What are the animal epidemic prevention measures for flood and waterlogging disasters? Please put away this technical guide for epidemic prevention and control.

Since the beginning of summer in the south, many places have been hit by torrential rains and floods, and epidemic diseases are also easy to occur after floods, especially animals. What are the animal epidemic prevention measures for flood and waterlogging disasters? Please put away the following technical guide for epidemic prevention and control.

Technical guide for prevention and control of animal diseases caused by flood and waterlogging

When a flood occurs, a large number of livestock and poultry die as a result of the disaster, the corpses decompose, the pathogen is easy to spread, a large number of pathogenic microorganisms in the soil are exposed, and the environment is easy to pollute the water source. The resistance of livestock and poultry has declined and is vulnerable to epidemic diseases, resulting in major animal diseases such as African classical swine fever, foot-and-mouth disease, highly pathogenic pig blue ear disease and highly pathogenic avian influenza, as well as the occurrence and prevalence of many zoonotic diseases such as schistosomiasis, anthrax, streptococcosis, leptospirosis and so on.

In order to do a good job in the prevention and control of COVID-19 and animal epidemic prevention after the disaster, the disaster areas should focus on the following work: first, timely innocuous treatment of sick and dead animals; second, comprehensive disinfection of farms, slaughterhouses, trading markets and livestock and poultry carcasses; third, strengthening biosafety protection measures and animal disease vaccination The fourth is to strengthen feeding and management to ensure the safety of livestock and poultry feed and drinking water, and to ensure the sanitation of the breeding environment; fifth, to do a good job in the protection of COVID-19 of the staff in the disaster areas. when handling sick and dead animals, the staff should wear protective clothing, wear masks, and wash hands frequently, so as to strengthen personal health protection; once the staff are found to have suspected COVID-19 's illness, report to the health department in a timely manner.

I. harmless treatment of sick and dead livestock and poultry

When there is a flood disaster, due to a large number of microorganisms in the dead livestock and poultry, if they are not treated innocuously in time, they will rot and stink, and the germs will spread everywhere, which will not only pollute the environment, but also easily lead to zoonosis. According to the "Technical Specification for harmless treatment of sick and dead animals" and other relevant provisions to deal with sick and dead animals.

(1) treatment methods

Timely salvage of dead livestock and poultry carcasses, incineration, chemical system and other methods for professional harmless treatment, do not have the conditions can choose deep burial, deep burial should choose Gaogang area, conditional places can be incinerated after deep burial treatment.

(2) Technical points of deep burying of livestock and poultry carcasses in disaster areas

1. facilities and equipment. According to the number of dead animals, prepare working tools, such as trucks (laying plastic film on the bottom contact surface of the truck), tractors, excavators, bulldozers, loading and unloading tools, animal carcass loading bags (preferably sealed), etc. Transport vehicles should prevent body fluid leakage, and the contact surface should be easy to clean and disinfect repeatedly.

2. Transportation of livestock and poultry carcasses. Animal carcasses are best packed in sealed bags, transport vehicles are airtight and impervious, and vehicles and related transport facilities should be disinfected when they leave the enclosure and burial sites. Animal carcasses shall not be transported in the same car with food, live livestock and poultry.

3. Selection of deep burial pit for livestock and poultry. There is enough sealing soil cover, the soil permeability is not high (for example, the soil permeability is high, the bottom of the burial site is at least 1 meter higher than the groundwater level), and there is a certain distance from rivers, lakes, ponds, wells and other water bodies, at least 100 meters ~ 150 meters. in addition, it is necessary to consider to facilitate the arrival of animal carcasses, avoid public view, at least 100 meters away from residential areas, and avoid spillways, places often washed by floods and rock layers.

Under specific circumstances, dead animals on the farm can be considered to be buried on the spot. Scattered small animals (such as chickens) can be buried under the roots of trees.

4. Excavation of buried pits. The volume of the pit is generally 2 to 4 times the volume of the animal carcass. The width of the pit is generally not less than 1.2 meters, the depth is generally 2 meters, not more than 3 meters, and the length should be able to accommodate all dead animals. The bottom of the pit should be relatively flat. The volume of the pit can be calculated according to the estimated weight of animal carcass: volume of animal carcass (cubic meter) = estimated weight of animal carcass (kg) / 1000.

5. Burying methods and requirements. Spread quicklime at the bottom of the burial pit, and then lay some combustible substances; after placing the body in the pit, pour fuel into the pit for incineration, and after incineration, add soil cover, the thickness of the soil layer shall not be less than 1.5 meters. When there are a large number of small animal carcasses, they can be burnt and buried in layers. The thickness of each layer of carcasses is generally not more than 0.3 meters, and the middle layer is laid with combustible material at least 0.3 meters, then burnt and buried in turn, and finally the thickness of the covered soil layer shall not be less than 1.5 meters. In the process of burying, the buried soil shall not be compacted, so as not to affect the natural decay. After burying, wild animals (wild dogs, cats, etc.) should be prevented from digging.

6. Set up warning lines and warning signs around the harmless disposal site. Prevent personnel from entering the danger by mistake; arrange regular inspections by staff as required to prevent illegal elements from digging up livestock and poultry carcasses and reselling them.

7. It is forbidden to dissect the carcasses of livestock and poultry that have died of anthrax and other common diseases, and they must not be buried directly. The bodies must be incinerated first, and then the incinerated material must be buried deep together after the incineration is complete.

8. Animal carcasses found in the wild should also be collected in time for harmless disposal.

(3) Protection and safety of staff

First, staff in harmless disposal operations, to wear protective clothing, rubber gloves, masks, goggles and rubber boots. The second is to clean and disinfect in time after disposal, accept health monitoring, and go to the health department for examination as soon as possible when there are adverse symptoms.

(4) Livestock and poultry excreta and sewage treatment

Livestock and poultry manure, bedding grass and sewage must all enter the biogas digester or concentrate and accumulate, and can be returned to the field after airtight fermentation for 42 days; a small amount of feces or bedding grass can be dried and dried and then incinerated; the sewage from the farm must be precipitated three times before the clear water can be discharged.

(5) inform farmers that it is strictly forbidden to throw livestock and poultry carcasses into water sources, rivers, roadsides and other places at will.

2. Disinfection

Flood-stricken areas suffer from continuous heavy rainfall, dead livestock and poultry and all kinds of dirt flow with the water, and the water source and other environment are easy to be polluted. At the same time, the pathogen in the soil is washed out by Rain Water, which will also cause epidemic disease. In order to eliminate pathogens in the environment, cut off the route of transmission, prevent and control the epidemic of infectious diseases, and protect the health of human beings and animals, large-scale disinfection must be carried out. The animal husbandry and veterinary departments in the disaster areas should guide the affected breeding farms (households) to carry out disinfection work, and guide large-scale breeding farms and breeding communities to implement sanitary disinfection measures to prevent the occurrence of epidemic situation.

(1) scope of disinfection

After the flood, it is necessary to guide the breeding farms (households) in the disaster areas to do a good job in cleaning and disinfecting the enclosure and its surrounding environment. First, it is necessary to do a good job in cleaning the environment of the enclosure to prevent the invasion of wild animals and eliminate rats, mosquitoes and flies; second, all enclosures should be thoroughly disinfected. The key points of disinfection are livestock and poultry houses, slaughterhouses (sites), processing of livestock and poultry and their products, sales sites, warehouses, transit sites, livestock and poultry trading markets, drinking water sources, livestock and poultry transport vehicles, appliances, etc.; in particular, the enclosures of dead animals are thoroughly and repeatedly disinfected.

1. Enclosure and environmental disinfection: thoroughly clean and disinfect the enclosure and its surrounding environment after the disaster. One is to disinfect collapsed enclosures, with emphasis on thoroughly disinfecting dead animals and enclosures; the other is to disinfect farms that can continue to be used, with regular cleaning of large farms and regular disinfection with disinfectants, keep the enclosure clean and hygienic, prevent the invasion of wild animals, and eliminate rats, mosquitoes and flies. Small farms and free-range farmers focus on regular cleaning of enclosures and disposal of faeces to keep them clean. In the event of an epidemic, chemical disinfectants or disinfectants should be used for disinfection. Third, the reconstruction of enclosure disinfection, in addition to routine disinfection, after the disaster should also increase the number of disinfection according to the epidemic situation of the disease, choose appropriate disinfection drugs. Where conditions permit, biogas digesters should be set up to ferment feces to prevent mosquitoes and flies from breeding.

2. Disinfection management of live livestock and poultry trading market: disinfect the body surface of livestock and poultry such as chickens and pigs with small irritants, clean and disinfect livestock and poultry trading places, transport vehicles and cages, etc., and establish a regular disinfection system.

(2) commonly used disinfectants and methods of use

1. Quicklime: it is suitable for spraying and disinfecting the walls, piles and floor of the shed. The preparation method of lime water is as follows: 1 kg quicklime plus 4 kg 9 kg water. First put the quicklime in the bucket, add a small amount of water to dissolve it, and then add enough water. Limewater should be ready for use, and it will fail if it is kept for too long.

2. Caustic soda: 2% caustic soda solution can be used to disinfect sheds, sites, appliances and vehicles, etc. 3% to 5% caustic soda solution can disinfect the ground contaminated by anthrax spores. When disinfecting the shed, drive (lead) the livestock out of the pen, after half a day, rinse the sterilized feed trough, sink, cement floor or wooden floor with water, and then let the livestock into the cage.

3. Peracetic acid: 2%-5% peracetic acid solution, which can be sprayed to disinfect sheds, sites, walls, appliances, vehicles, ships, feces, etc.

4. Compound phenol: compound phenol 100: 300 times solution is suitable for disinfecting livestock barn, site, dirt and so on.

5. Quaternary ammonium salts: spray, rinse and impregnate with 3000 times diluent, which can be used to disinfect barns, environment, machinery, utensils, breeding eggs and so on. 2000 times of quaternary ammonium salts can be used for emergency prevention of disinfection of livestock and poultry houses. Quaternary ammonium salts diluted 10000-20000 times can prevent water storage towers and drinking fountains from being clogged by dirt, kill microorganisms, remove algae, deodorize and improve water quality.

In addition, chlorine, iodine, acid and other disinfectants can be selected to disinfect the environment and instruments of the enclosure according to the requirements of the instructions.

(3) the frequency of disinfection

Ensure the frequency of disinfection. After the disaster, the environment is disinfected at least twice a week, and the enclosure can be disinfected with livestock and poultry 3 or 4 times a week. In the event of an epidemic, the frequency of disinfection should be increased and the disinfection effect should be monitored.

It is necessary to ensure the effective concentration of disinfection drugs and prevent the mixed use of acid-base disinfectants to affect the disinfection effect.

(4) disinfection of staff

After completing the harmless disposal and disinfection work, the staff should incinerate the protective clothing, gloves and masks taken off; after contact with pollutants, they should use hand-free disinfectant to wipe their hands, and the disinfection time should be not less than 1 minute. Then wash it with water.

III. Immunization and surveillance of major animal diseases

Farmers of large-scale farms should, in the light of the actual situation of prevention and control, earnestly do a good job in the biosafety of African classical swine fever, and do a good job in the replenishment and immunity of major animal diseases such as foot-and-mouth disease, highly pathogenic avian influenza, highly pathogenic swine blue ear disease, and swine fever. Livestock and poultry with unqualified immune antibodies should be replenished and exempted in a timely manner.

(1) strengthen immunity and effectively improve the self-resistance of livestock and poultry

Immunization is an effective measure to prevent and control major animal diseases such as foot-and-mouth disease, highly pathogenic porcine blue ear disease, highly pathogenic avian influenza and so on. According to the situation of emergency surveillance, supplementary immunity and enhanced immunization against major animal epidemics such as highly pathogenic swine blue ear disease, avian influenza, foot-and-mouth disease, and classical swine fever should be carried out as soon as possible for livestock and poultry with low antibody levels, which are about to exceed the period of immune protection, and for new fences. Focus on testing the antibody level of households in large-scale farms to ensure the level of immune antibodies in large-scale farms. Special efforts should be made to strengthen the immunization of sows and weaned piglets. In the light of the local epidemic situation, emergency immunization should be carried out in old epidemic areas, densely populated areas and areas around temporary resettlement sites. It is necessary to actively carry out the "Law on Animal epidemic Prevention" and publicity on the knowledge of animal disease prevention and control for grass-roots epidemic prevention personnel and the broad masses of farmers, so as to earnestly improve the epidemic prevention level of grass-roots epidemic prevention personnel and farmers' awareness of independent epidemic prevention.

(2) strengthen surveillance and eliminate the hidden dangers of the epidemic situation in a timely manner

It is necessary to further strengthen animal epidemic surveillance and epidemiological investigation in disaster-stricken areas so as to detect and eliminate hidden dangers in a timely manner. Focus on antibody testing for livestock and poultry in large-scale farms (households), areas where outbreaks have occurred and other high-risk areas. When it is found that the epidemic situation should be sampled and submitted for inspection in time, surveillance and epidemiological investigation should be done well, and the causes of the epidemic situation should be comprehensively analyzed. According to the monitoring results, animal husbandry and veterinary departments in disaster areas should strengthen supervision and inspection to ensure that various prevention and control measures are implemented; veterinarians in counties and townships should strengthen the inspection of breeding farms (households), report the epidemic situation in time, and deal with it in time.

Prevention of mildew feed poisoning and feeding management

(1) Prevention of mildew feed poisoning

The continuous heavy rain and high humidity in the disaster area can easily cause feed mildew, and molds in moldy feed can cause animal poisoning. After poisoning, animals generally have normal body temperature, dry feces and vomiting symptoms. The sow is infertile and has miscarriage. Some have neurological symptoms and some die seriously. There are many parts of the body including visceral bleeding and liver necrosis.

There is no effective treatment for mildew feed poisoning, focus on prevention, it is strictly forbidden to feed spoilage, deterioration or mildew feed. Moldy feed can be incinerated or returned to the field; pay attention to the shelf life of the feed to prevent the consumption of expired feed.

(2) strengthen feeding and management

First, it is necessary to dredge the drainage channel of the livestock and poultry farm as soon as possible, remove the stagnant water in the livestock house, repair and strengthen the damaged livestock house, and if it cannot be repaired in time, the livestock and poultry should be transferred to dry and safe areas as soon as possible. Second, it is necessary to create a good feeding environment, maintain hygiene in the barn, clean up feces in time, and do a good job of ventilation. Third, we should provide nutritious feed and clean drinking water. Feed less frequently to avoid mildew. Compound vitamin B and Vc can be added to drinking water to enhance the resistance of livestock and poultry, increase appetite and eliminate stress. Fourth, it is necessary to strengthen the breeding of livestock and poultry, do a good job in protecting the fetus of female livestock, increase nutrition and timely breeding of aborted female livestock, and strengthen the conservation of young animals at the same time. Fifth, livestock and poultry that are young, weak, disabled and seriously ill should be eliminated in time to reduce the cost of raising. Commercial livestock and poultry that reach the standard should be released as soon as possible to reduce the breeding density.

V. Prevention and control of animal diseases after flood and waterlogging disasters

Animal diseases prone to flooding include schistosomiasis japonica, anthrax, streptococcosis suis, leptospirosis, porcine lung disease, swine erysipelas, Japanese encephalitis, highly pathogenic porcine blue ear disease, African swine fever and so on.

(1) Schistosomiasis japonica

Schistosomiasis japonica is a zoonotic parasitic disease caused by Schistosoma japonicum parasitic on humans or mammals. The Ministry of Agriculture and villages listed it as a Class II animal epidemic and the State Health Commission classified it as a Class B human infectious disease.

1. Epidemic situation

The endemic areas of schistosomiasis japonica in China can be divided into three types: water network type, lake marsh type and hill type. Water network type: located between the Yangtze River and Qiantang River, that is, the vast plain area of the Yangtze River Delta. Lake and marsh type: it is located in the beaches along both sides of the middle and lower reaches of the Yangtze River and the vast lake area connected with the Yangtze River. Hill type: mainly distributed in the mountainous and hilly areas of Sichuan and Yunnan provinces.

The feces of animals and patients with schistosomiasis japonica contain live eggs, which is the main source of infection of the disease. Pigs and dogs themselves are hosts and can become sources of infection. Almost all mammals are susceptible to Schistosoma japonicum. Cattle (buffalo, yellow cattle) and sheep are the most susceptible, and so are people. The disease is infected mainly through skin, mucous membrane and contact with epidemic water. Infected snails escape from cercariae to pollute the water source, and the water containing cercariae is called epidemic water, and people and animals come into contact with the epidemic water. Water transmission is the main route of transmission of schistosomiasis. The frequency and area of contact between various animals and epidemic water are different, so the infection rate and the degree of infection are also different. The infection rate and infection degree of the same kind of animals are also different in different regions.

2. Clinical symptoms

The clinical symptoms varied with the breed, age and infection intensity of infected domestic animals. generally, yellow cattle and dairy cows were more obvious than buffalo, equine animals and pigs, goats were more obvious than sheep, and calves were more obvious than adult cattle. The main clinical symptoms are emaciation, rough coat, diarrhea, hematochezia, growth stagnation, decreased farming ability of serviced cattle, decreased milk yield of dairy cows, infertility or abortion of female animals, and a small number of suffering animals, especially calves and sheep with severe infection. often long-term diarrhea, hematochezia, rectal valgus, pain, appetite cessation, gait sway, long-term bedridden, slow breathing, and finally failure and death.

The clinical symptoms of human infection with schistosomiasis can be divided into acute, chronic and late stages. The symptoms of acute schistosomiasis, mostly occur in the first infection, some people in the contact site of the skin dotted red papules, strange itching. The main symptoms of chronic schistosomiasis are chronic diarrhea or dysentery. There are several types of advanced schistosomiasis, (1) ascites type, ascites is one of the main signs of advanced schistosomiasis, (2) giant spleen type, (3) dwarf type, (4) colon proliferation type. The common complications of advanced schistosomiasis are upper gastrointestinal bleeding and liver coma. Massive hemorrhage of upper digestive tract and liver failure are the main causes of death.

3. prevention and control measures

Implementation of agricultural schistosomiasis control key projects such as agricultural engineering snail control (water to drought, flood and drought rotation, ditch hardening, snail control by breeding) and management of infectious sources of livestock (captivity of livestock, replacement of cattle by machines, construction of biogas digesters, investigation and treatment of livestock), protection of water sources and safe grazing, cut off the route of transmission of schistosomiasis and prevent and control schistosomiasis.

The disease was detected by etiological or serological methods in the epidemic area, or by serological screening, and the positive animals were diagnosed by etiological methods. The diseased animals were treated with praziquantel or all livestock exposed to epidemic water were treated with universal treatment. Make a good record of the treatment of sick animals and organize it into a book and file it for reference.

4. Public health and personnel protection

There are snail areas in schistosomiasis control areas, strengthen the warning signs, prevent grazing livestock and personnel from coming into contact with epidemic water, if necessary, personnel protection must be done.

People may be infected with Schistosoma japonicum as long as they come into contact with epidemic water, and then get sick. The more times you are exposed to epidemic water, the more likely you are to be infected with Schistosoma japonicum. Farmers, fishermen and boat people engaged in productive labor in schistosomiasis endemic areas are more likely to be infected. In recent years, people from epidemic areas to non-epidemic areas, from non-epidemic areas to epidemic areas, or from one epidemic area to another, the above-mentioned personnel should take the initiative to undergo examination when they develop symptoms such as rash, fever, abdominal pain, diarrhea, fatigue, liver discomfort, etc. Children and housewives should stay away from the epidemic water. Farmers engaged in production activities should wear protective equipment and use protective drugs. Wear high rubber overshoes or protective clothing and gloves; all parts that come into contact with epidemic water should be covered with protective drugs. At present, the main protective agents used are: protective ointment, skin to avoid the enemy, anti-cercaria cream, anti-cercaria pen and so on. At present, oral drugs are praziquantel, artesunate or artemether, which can kill schistosomiasis schistosomiasis entering the body, and the preventive effect is better. Do a good job in fecal treatment to prevent feces from polluting water sources and kill Schistosoma japonicum eggs in feces.

(2) anthrax

Anthrax is a zoonotic disease caused by Bacillus anthracis. The Ministry of Agriculture and villages listed it as a second-class animal epidemic.

1. Diagnosis and epidemic characteristics

The disease is a zoonotic disease, all kinds of livestock, wild animals and people have varying degrees of susceptibility to the disease. Herbivores are the most susceptible, followed by omnivores, followed by carnivores, poultry are generally not infected, and people are also susceptible.

The disease is endemic. There is a certain seasonality, most of which occur in the season when there are many blood-sucking insects, Rain Water and flooding.

The main infectious sources of the disease are diseased animals and animal carcasses killed by anthrax, as well as contaminated soil, grassland, water and feed. Anthrax spores have strong resistance to the environment, and their contaminated soil, water sources and sites can form lasting epidemic foci. The disease is mainly infected through digestive tract, respiratory tract and skin.

2. Clinical symptoms

The disease is mainly acute, characterized by sudden death, natural pore bleeding and incomplete rigor.

Cattle: body temperature often rises to more than 41 ℃, visible mucosa is dark purple, tachycardia, dyspnea. In chronically diseased cattle, edema is common in the neck, chest, scapula, abdomen or vulva; skin lesions are elevated in temperature, hard, tenderness, necrosis and sometimes ulcers; neck edema is often accompanied by pharyngitis and laryngeal edema, resulting in increased dyspnea. Acute cases usually die after 24-36 hours, and subacute cases die after 2-5 days.

Horse: elevated body temperature, common edema under the abdomen, breast, shoulder and throat. Tongue anthrax is more common dyspnea, cyanosis, intestinal anthrax abdominal pain is obvious. Acute cases usually die after 24-36 hours, and when there is anthrax carbuncle, the course of disease can reach 3-8 days.

Sheep: most of the symptoms are the most acute (sudden death), including swinging, grinding teeth, convulsions, struggle, sudden death, and some black-red blood with bubbles can be seen flowing out of the natural hole. The course of the disease lasted only a few hours and then died.

Pigs: most of them are localized changes, showing chronic process, clinical symptoms are not obvious, and pathological changes are often seen after slaughter.

The clinical symptoms of dogs and other carnivores are not obvious.

3. Disposal of epidemic situation

After receiving the report of suspected anthrax epidemic, the local animal husbandry and veterinary department shall promptly send personnel to the scene to conduct epidemiological investigation and clinical examination, collect disease materials and send them to meet the requirements of laboratory diagnosis, and immediately isolate suspected sick animals and animals of the same group. restrict movement. Autopsy and examination of dead animals are strictly prohibited, and sampling must be carried out in accordance with regulations to prevent pathogens from polluting the environment and forming permanent epidemic foci.

When the disease is sporadic, the diseased animals should be treated with bloodless killing, and the animals in the same group should be forcibly vaccinated immediately and isolated for 20 days. Harmless treatment of dead animals and excreta, possibly contaminated feed and sewage as required; strict and thorough disinfection of potentially contaminated articles, means of transport, appliances and animal houses. All susceptible animals in epidemic areas and threatened areas were vaccinated urgently. Open dissection and examination of dead animal corpses is strictly prohibited, and sampling must be carried out in accordance with regulations to prevent pathogens from polluting the environment and forming permanent epidemic foci.

When the disease presents an outbreak (more than 5 diseased animals are found in a county within 10 days), it should be reported to the people's government at the same level to blockade the epidemic area; disinfection facilities must be set up at the entrance and exit of the epidemic spot. Restrict the entry and exit of people, susceptible animals, vehicles and the movement of animal products and potentially contaminated goods. Animal houses, sites and all means of transport and drinking water utensils in the epidemic spot must be strictly and thoroughly disinfected. All the sick animals and the animals of the same group were culled without blood. Emergency vaccination of other susceptible animals. All sick and dead animals, culled animals, as well as feces and potentially contaminated pads, feeds and other articles and products shall be treated innocuously as required. When animal carcasses need to be transported, leak-proof containers shall be used, which shall be clearly marked and carried out under the supervision of animal disease prevention and control agencies. Stop the trading and movement of animals and their products in the epidemic area. All susceptible animals must be kept in captivity or kept in designated places; disinfect animal houses, roads and other places that may be contaminated. All susceptible animals in epidemic areas and threatened areas were urgently immunized, and epidemic source analysis and epidemiological investigation were carried out.

4. Prevention and control measures

One is environmental control. Breeding, production, business premises and slaughterhouses must comply with the conditions for animal epidemic prevention stipulated in the measures for the examination of conditions for Animal epidemic Prevention, and establish a strict hygiene (disinfection) management system. The second is immunization. According to the epidemic situation of the local epidemic, according to the immunization program made by the Ministry of Agriculture and Village, the target and scope of immunization are determined; the anthrax vaccine approved by the state is used, and timely immunization is carried out according to the immunization procedure, and the immunization record is made. The third is to disinfect the source. Regular disinfection should be carried out in new and old epidemic areas, with emphasis on disinfection in case of flood and waterlogging disasters. Skin, hair, etc., shall be disinfected as required.

5. Personnel protection

The staff of animal epidemic prevention and quarantine, laboratory diagnosis and breeding farms, animal products and leather processing enterprises should pay attention to personal protection, and the relevant personnel involved in the handling of the epidemic should wear protective clothing, masks and gloves to do a good job of self-protection. The skin was sterilized with ethylene oxide under high pressure.

(3) Streptococcus suis

Streptococcus suis is a zoonotic disease caused by hemolytic streptococci, which is listed as a second-class animal epidemic disease by the Ministry of Agriculture and Village.

1. Diagnosis and epidemic characteristics

Pigs of different ages, breeds and genders are susceptible and can also infect humans.

Streptococcus often exists in respiratory tract, digestive tract and reproductive tract of normal animals and human beings. Pathogens exist in feces, secretions, blood, internal organs and joints of infected animals.

Diseased pigs and infected pigs are the main sources of infection of the disease. improper disposal of dead pigs and pollution of means of transport are important factors for the spread of the disease.

The disease is mainly infected by digestive tract, respiratory tract and injured skin. It can happen all the year round, especially in summer and autumn. It is endemic, the new epidemic area can be an outbreak, and the morbidity and mortality are high. Most of the old epidemic areas are sporadic, and the morbidity and mortality are low.

2. Clinical symptoms

It can be divided into septic type, meningitis type and lymph node abscess type.

Septic type: divided into the most acute, acute and chronic three types. The most acute type has an acute onset and a short course of disease, and often dies suddenly without any symptoms. The body temperature was as high as 41 ℃, shortness of breath, and most of them died of septicemia within 24 hours. Most of the acute type occurred suddenly, with a temperature rise of 40 ℃, shortness of breath, dry nose and serous or purulent secretions from the nasal cavity. Conjunctiva flushed and shed tears. The skin of the neck, auricle, lower abdomen and lower extremities is purplish red with bleeding spots. Most of them died in 1Mel for 3 days. The chronic type is characterized by polyarthritis. The joint is swollen, crippled or paralyzed, and finally dies of weakness and paralysis.

Meningitis type: mainly meningitis, more common in piglets. The main manifestations are neurological symptoms, such as molars, foaming at the mouth, circle movement, convulsions, falling limbs like swimming, and finally paralysis and death. The short course of disease is a few hours, and the long one is 5 days. The fatality rate is extremely high.

The type of lymph node abscess is characterized by suppuration and abscess of lymph nodes in submandible, pharynx and neck.

3. Disposal of epidemic situation

When a suspected epidemic of Streptococcus suis is found, the local animal husbandry and veterinary department should promptly send personnel to the scene to carry out epidemiological investigation, clinical symptom examination, etc., and sample for inspection. When it is confirmed as a suspected epidemic of Streptococcus suis, prevention and control measures such as isolation and movement restriction should be taken immediately.

When the disease is sporadic, the diseased pigs should be killed without blood, and the pigs in the same group should be vaccinated or prevented with drugs immediately, and quarantined and observed for 14 days. Culling the same herd of pigs if necessary. The culled pigs, sick and dead pigs and feces, potentially contaminated feed and sewage shall be treated innocuously in accordance with the relevant regulations, and the articles, means of transport, appliances and livestock houses that may be contaminated shall be strictly and thoroughly disinfected. All susceptible animals around are urgently immunized.

When the disease breaks out (more than 50 diseased pigs or more than 2 villages and towns are found in a township within 30 days), the diseased pigs in the epidemic spot should be treated without blood, and the pigs in the same group should be vaccinated or prevented with drugs immediately. And quarantined for 14 days. Culling the same herd of pigs if necessary. Carry out harmless treatment of sick and dead pigs and excreta, possibly contaminated feed and sewage according to the requirements of the attachment; strictly and thoroughly disinfect the articles, means of transportation, appliances and livestock houses that may be contaminated. Animal health supervision and inspection stations shall be set up on major traffic roads, special personnel shall be sent to supervise the movement of animals and their products, and people and vehicles entering and leaving shall be disinfected. Stop the trading, slaughtering, transportation and movement of live pigs in the epidemic area. Disinfect livestock houses, roads and other places that may be contaminated. For the same group of healthy pigs in the epidemic area and pigs in the epidemic area, high-sensitive antibiotics can be used for emergency preventive administration. All pigs in the epidemic area and the threatened area shall be urgently immunized according to the instructions.

Pig excreta and contaminated or possibly contaminated pads, feeds and other articles need to be treated innocuously. Leak-proof containers should be used when transporting pig carcasses.

4. Personnel protection

The relevant personnel involved in dealing with the epidemic should wear protective clothing, rubber shoes, masks and gloves to protect themselves.

(4) Leptospirosis

Leptospirosis (leptospirosis) is a zoonotic disease caused by pathogenic Leptospira (Leptospira for short), commonly known as "threshing yellow" and "rice blast". The Ministry of Agriculture and villages listed it as a Class II animal epidemic and the State Health Commission classified it as a Class B human infectious disease.

1. Epidemic situation

Cases of leptospirosis have been reported in other provinces and cities except Xinjiang, Qinghai, Gansu and Ningxia, and it is more serious in south-central, southwest and east China, which are rich in rice. In the rice harvest season and flood relief, large-scale epidemics often occur due to the large number of people exposed to water contaminated by Leptospira.

The host of Leptospira is very extensive. Domestic animals such as pigs, dogs, cattle, sheep and horses, and wild animals such as rats, wolves, rabbits, snakes and frogs can be sources of infection. Rodents and pigs are the two main sources of infection.

Leptospira can survive for a long time in micro-alkali and containing certain humus (such as rice field water) and silt. Leptospira is a water-borne epidemic disease. After animal infection, pathogens can be excreted with urine through the kidney, polluting water, soil, feed, cattle pens, utensils and so on. The disease is transmitted through the skin, mucosa and digestive tract, as well as by mating, artificial insemination and blood-sucking insects during bacteremia. It is generally endemic or sporadic, and it is more common in summer and autumn. young animals are more susceptible than adult animals and the disease is serious.

When people come into contact with water contaminated by Leptospira in production, labor or life, pathogens can enter the human body through skin (especially damaged skin) and mucous membrane, causing human disease. Direct contact infection refers to the infection caused by direct contact with pathogens in animals in the process of raising, slaughtering, processing and transporting animals. Occasionally there are reports of mother-to-child vertical transmission, but human-to-human transmission is of little significance.

Almost all animals can be infected, and rodents are the most susceptible and most important storage hosts. Followed by pigs, buffaloes, cattle and ducks, followed by sheep, horses, camels, rabbits and cats. Poultry can also be infected. People are generally susceptible to leptospirosis. Residents of non-epidemic areas are particularly susceptible to entering the epidemic area.

The disease is a natural infectious disease. Cases are relatively concentrated during rice harvest in summer and autumn or after heavy rains and floods, and can be seen all the year round in areas with higher temperatures. The disease is common among young and middle-aged farmers, and other fishermen, miners, butchers and breeders who have more opportunities to come into contact with water contaminated by Leptospira can also occur.

2. Clinical symptoms

The clinical features of acute cases mainly showed short-term fever, anemia, jaundice, hemoglobinuria, mucosal and skin necrosis and other symptoms. But most animals are recessive infection, lack of obvious clinical symptoms.

Cattle: nine types of Leptospira were isolated from cattle in China, mainly Pomona group, followed by jaundice bleeding group, often lack of typical symptoms, only weight loss and diarrhea. In typical cases, the acute course was taken, and the initial body temperature was more than 40.5ml / 41 ℃. Depressed spirit, loss of appetite, dry nose, even cracked, gradually emaciated. The amount of lactation decreases or stops, and the milk turns yellow in the shape of colostrum, and there are often blood clots. In some cases, 3 days after abortion, visible mucosal yellow staining and hemoglobinuria occurred. Skin necrosis often occurs in the oral mucosa, ear, head, breast and external genitalia of diseased cattle. The chronic cases showed intermittent fever, the diseased cattle gradually lost weight, jaundice and hemoglobinuria appeared from time to time.

Pig: leptospirosis is more common in pigs. Fourteen bacterial types have been isolated from pigs in China, mainly Pomona group, followed by dog group. Most of them have no obvious clinical symptoms. Acute cases were mostly seen in piglets, showing short-term fever (about 39.8 ℃) and conjunctivitis. Depressed spirit, loss of appetite, yellow staining of visible mucosa, edema of the head. Skin elasticity decreased, skin necrosis appeared in the later stage, and the urine was yellowish and brown. Miscarriage and stillbirth often occur in sows in the third trimester of pregnancy.

Ma: most of them are recessive infection, and there are few acute cases. The symptoms of acute sick horses are similar to those of cattle, mainly showing elevated body temperature, mental depression, conjunctivitis and visible mucosal yellow staining. The urine volume is small, the urine is sticky, showing a yellowish red soybean oil sample. Pregnancy horse abortion, hemoglobin decreased, white blood cell count increased, neutrophils increased, nucleus moved to the left.

People: the incubation period is 2-20 days, usually 7-13 days. The course of the disease can be divided into three stages: early "severe cold-like" syndrome, with "three symptoms", that is, chills and fever, muscle soreness, and general fatigue; three signs, namely, conjunctival congestion, gelatinous intestinal muscle tenderness, and enlarged lymph nodes. The middle stage can be divided into four types. Influenza typhoid type, pulmonary hemorrhage type, jaundice bleeding type, meningoencephalitis type. There will be varying degrees of organ damage. Such as epistaxis, hemoptysis, diffuse pulmonary hemorrhage, skin and mucous membrane jaundice or bleeding point; renal type patients with proteinuria, hematuria, tubular urine and other renal function damage; meningoencephalitis patients with severe headache, vomiting, neck ankylosis and cerebrospinal fluid composition changes. Some symptoms or organ damage occur again within 6 months after acute fever (some can be as long as 9 months). The common late-onset symptoms are post-fever, ophthalmic sequelae, allergic meningitis and so on. The pathological basis of leptospirosis is systemic capillary toxic injury, a large number of leptospirosis invaded internal organs such as lung, liver, kidney, heart and central nervous system, resulting in organ damage and corresponding organ complications. The severity of the disease is related to the type, quantity and virulence of Leptospira. Leptospira with high virulence can cause serious manifestations such as pulmonary hemorrhage or jaundice bleeding.

3. Differential diagnosis

A preliminary diagnosis is made according to clinical symptoms, epidemiological investigation and pathological changes, and laboratory diagnosis is needed for diagnosis.

It should be distinguished from hemocystis, postpartum hemoglobinuria, bacterial hemoglobinuria, equine infectious anemia and jaundice and abortion caused by other pathogens.

4. Prevention and control measures

Animals can use penicillin, others such as streptomycin, chloramphenicol, gentamicin and so on have a good effect on the disease. In addition, the new arsenic vannamine also has a good effect.

Carrying out mass comprehensive preventive measures, rodent control and vaccination are the key to control the outbreak and reduce the incidence of leptospirosis. We will carry out mass campaigns to kill rats and protect food, kill rats and prevent diseases. Combined with the work of "two pipes (water, dung) and five reforms (wells, toilets, livestock pens, stoves and environment), it is especially necessary to promote the management of pig manure and urine manure, so as to achieve the purpose of preventing pollution of water sources, rice fields, ponds and rivers. Pay attention to drinking water hygiene, isolate diseased animals, and strictly prevent urine pollution of drinking water and feed. Residents, troops and people who may come into contact with epidemic water in harvesting, flood control and drainage should be vaccinated with Leptospira polyvalent vaccine with the same epidemic type as possible one month in advance. In frequently affected areas, Leptospira vaccine can be inoculated. Kill rodents and wild dogs. For those who are susceptible to high risk, such as pregnant women, children, adolescents, the elderly or laboratory staff who accidentally come into contact with Leptospira, suspected infection but no obvious symptoms, penicillin can be injected 80 ~ 1.2 million U daily for 2 ~ 3 days.

5. Public health and personal protection

The disease is a natural epidemic disease, carrying animals can discharge bacteria into the environment for a long time, when susceptible animals and humans come into contact with the pathogen, can be infected, in rice-producing areas in China, there have been cases, especially floods and natural disasters, often outbreaks. People in disaster areas mainly prevent leptospirosis by killing rats (such as drugs), preventing rats (such as farmland reconstruction), managing livestock to reduce environmental pollution (such as captive pigs), and avoiding contact with epidemic water as far as possible, such as drying and drying the water in the field before harvesting paddies. If necessary, take leptospirosis vaccination, oral drug prevention, and so on. High-risk groups such as fishermen, miners, butchers and breeders who have frequent contact with epidemic water and personnel who work on the spot in the epidemic area of leptospirosis should avoid contact with epidemic water and wear protective gloves when investigating the density and carrier rate of animal hosts. Do not touch animals and their carcasses directly. If necessary, leptospirosis can be vaccinated 15 days before entering the epidemic area, or oral doxycycline and other emergency prevention of leptospirosis infection.

(5) Porcine lung disease

Porcine lung disease (pasteurellosis) is an acute infectious disease caused by Pasteurella multocida.

1. Popular characteristics

Pasteurella multocida can infect a variety of animals, pig is one of them, pigs of all ages can be infected, the incidence of piglets and middle pigs is higher. Sick pigs and healthy infected pigs are sources of infection. pathogens are excreted from secretions and feces and are transmitted through respiratory tract, digestive tract and injured skin. When infected pigs suffer from cold, cold, overwork and improper feeding and management, when the resistance is reduced, autogenic infection can occur. Porcine pulmonary disease is often sporadic, when pigs are in adverse external environment, such as cold, muggy, climate upheaval, dampness, crowding, poor ventilation, lack of nutrition, fatigue, long-distance transportation, etc., resulting in a decline in resistance of pigs. at this time, the pathogen proliferated and caused the disease. In addition, diseased pigs pass bacteria through secretions and feces to pollute drinking water, feed, utensils and the external environment, and transmit them to healthy pigs through the digestive tract, which is also an important way of transmission. The pathogen can also be discharged by coughing and sneezing and transmitted through the respiratory tract through droplets. In addition, blood-sucking insects bite the skin and mucous membrane wounds can be contagious. The disease generally has no obvious seasonality, but it occurs frequently in hot and cold alternation, changeable climate and high temperature in flood-stricken areas, which is generally sporadic or local epidemic.

The disease is common in middle and small pigs; in the four seasons of the year, it occurs most frequently in late autumn, early spring and abrupt climate change season, and it is easy to occur in the humid and muggy May-September in the south, with epidemic porcine lung disease.

2. Clinical symptoms

The incubation period of the disease is 1-5 days, usually about 2 days. The main symptoms were marked increase in body temperature (42.2 ℃), loss of appetite, extreme difficulty in breathing, persistent cough, visual mucosal purulent conjunctivitis, constipation followed by diarrhea, erythema in the ear root, ventral side and medial extremities, and the mortality rate was as high as 50%. Clinical symptoms can be divided into three types: the most acute, acute and chronic. The most acute type is often seen in the early stage of the epidemic and often dies suddenly. The course of the disease is a little longer, the body temperature rises (40-42 ℃), the appetite is lost, the whole body is weak, lying on the floor can not afford. Conjunctival congestion and cyanosis. Erythema occurs in the skin of the ear root, neck, ventral and lower abdomen, and the finger pressure is not completely faded. The most characteristic symptoms are redness, swelling, heat, pain and acute inflammation of the throat. In severe cases, local swelling can extend to the ear root and neck. Breathing is extremely difficult, mouth and nose bleed like foam, more than 2 days after asphyxiation to death. The acute type mainly presents fibrinous pleuropneumonia. In addition to the symptoms of septicemia, the initial body temperature increased to 40: 41 ℃, spastic dry cough, rhinorrhea and purulent conjunctivitis. Initial constipation, followed by diarrhea. Dyspnea, often do dog sitting posture, chest palpation has pain, auscultation has squeak and friction sound. Most of them died of suffocation. The course of the disease lasted for 4 to 6 days, and the undead became chronic. Chronic type mainly presents chronic pneumonia or chronic gastroenteritis. The diseased pig has persistent cough, dyspnea, nasal discharge of sticky or purulent secretions, and chest auscultation with rales and friction sounds. Joint swelling. Sometimes diarrhea, progressive malnutrition, extreme emaciation, and finally died of exhaustion, the course of disease 2-4 weeks.

3. Differential diagnosis

The most acute cases of this disease often die suddenly, the symptoms and pathological changes of chronic cases are not typical, and they are often mixed with other diseases, so it is difficult to make a definite diagnosis only by the diagnosis of epidemiology, clinical symptoms and pathological changes. it should be based on the comprehensive data of epidemiology, symptoms, pathological changes and bacteriological examination. Pay attention to the difference from classical swine fever and swine erysipelas. In the most acute cases, swelling and inflammation of the throat and jelly-like infiltration during autopsy were similar to septic anthrax, but acute anthrax in pigs rarely occurred and did not form an epidemic. During autopsy, the splenomegaly of anthrax is different from that of porcine lung disease, such as bacteriological examination of local disease materials, the pathogen morphology of the two is obviously different, and it is easy to distinguish.

4. Prevention and control measures

Pasteurella multocida is found in the upper respiratory tract of some healthy pigs, which can often induce the disease due to adverse factors. Therefore, the fundamental way to prevent this disease must carry out the policy of "prevention first", eliminate all bad factors that reduce the resistance of pigs, strengthen feeding and management, and do a good job of animal epidemic prevention in order to enhance the resistance of pigs; preventive injections are carried out regularly in spring and autumn every year to enhance the specific resistance of pigs.

When the disease occurs, isolate the sick pigs and treat them in time. Sick pigs can be injected with penicillin water 400000 units intramuscularly 3 times a day for 3 to 5 days. Streptomycin was injected intramuscularly twice a day. 20% sulfathiazole sodium or sulfadiazine sodium injection, 10~15mL for piglets and 20~30mL for big pigs, intramuscular or intravenous injection, twice a day for 3-5 days.

Do a good job of disinfection and nursing in flooded areas. The walls, floors, feeding and management appliances of the pig house should be disinfected, and the fecal waste should be accumulated and fermented; if necessary, the assumed healthy pigs of the diseased group can be urgently injected with porcine lung disease antiserum at a dose of half of the therapeutic dose; it is better to eliminate small stiff pigs suffering from chronic porcine lung disease.

(6) Porcine erysipelas

Porcine erysipelas is an acute febrile infectious disease caused by erysipelas suis.

1. Popular characteristics

Porcine erysipelas occurs all the year round. Diseased pigs and infected pigs are the source of infection of the disease. Erysipelas are mainly found in tonsils, gallbladder, glands of ileocecal valve and bone marrow of infected pigs. Infected pigs and infected pigs excreted erysipelas from feces and urine, contaminated feed, drinking water, soil, utensils and farms, and transmitted them to susceptible pigs through the digestive tract. The disease can also be transmitted by damaging the skin and blood-sucking insects such as mosquitoes and flies.

2. Clinical symptoms

It is divided into two types: acute and chronic. Acute septicemic porcine erysipelas is commonly seen with elevated body temperature up to 42-43 ℃, persistent, weak, not eating, and sometimes vomiting. The feces are dry and hard in the shape of millet, with mucus, and piglets may have dysentery in the later stage. Severe rapid breathing, mucosal cyanosis, some diseased pig ears, neck, back and other skin flushing, purple. Those with a short course of disease can die suddenly, with a fatality rate of about 80%. Common skin necrosis of chronic porcine erysipelas often occurs in the back, shoulders, ears, hooves and tails, with local skin swelling, bulging, black, dry and hard, like leather. After 2-3 months, the necrotic skin fell off, leaving a hairless scar. Chronic arthritis shows swelling of the joints of the extremities, wrist joint is more common, leg stiffness, pain, lameness or lying on the ground can not afford. Shortness of breath, usually heart paralysis suddenly fell to the ground and died.

3. prevention and control measures

Strengthen feeding management, keep piggery utensils clean, and disinfect with disinfectants regularly. Vaccination is carried out as planned every year. At present, there are two types of vaccines for the prevention and treatment of this disease: attenuated vaccine and inactivated vaccine. The immune factors of suckling pigs may be affected by maternal antibodies and should be carried out after weaning; if they have been immunized during lactation, they should be immunized again after weaning and every 6 months thereafter. Do a good job of killing mosquitoes, flies and fleas in pig houses.

After the detection of swine erysipelas, the diseased pigs should be isolated and treated as soon as possible. Pig pens, sports grounds, feeding tanks and appliances should be carefully disinfected. Faeces and bedding grass had better be burned or piled up for biological heat treatment. After the outbreak of swine erysipelas, the temperature of the whole herd of pigs should be measured immediately, the diseased pigs should be isolated and treated, and the dead pigs should be buried or burned. Non-diseased pigs in the same group as diseased pigs were prevented with penicillin. After the epidemic was extinguished and stopped, a large-scale disinfection was carried out.

After the diseased pigs were isolated and disposed, the normal pigs were injected with porcine erysipelas vaccine to consolidate the epidemic prevention effect. The chronic disease pigs should be eliminated as soon as possible to reduce the economic loss and prevent the spread of bacteria.

(7) Japanese encephalitis

Porcine Japanese encephalitis (also known as Japanese encephalitis and Japanese encephalitis) is an acute zoonotic infectious disease of the central nervous system caused by Japanese encephalitis virus. Mosquitoes are the vector, and pigs are characterized by miscarriage, stillbirth and orchitis. The Ministry of Agriculture and villages listed it as a Class II animal epidemic and the State Health Commission classified it as a Class B human infectious disease.

1. Epidemic situation

China has the highest incidence of encephalitis B, accounting for more than 80% of the total number of cases in the world. So far, no je cases have been reported in Xinjiang, Qinghai and Xizang, but je cases have occurred in other provinces and cities. Japanese Encephalitis (je) is a natural focus disease with obvious seasonality, which mostly occurs in mosquito breeding and activity season from July to September. In addition to scattered occurrence in tropical areas throughout the year, subtropical and temperate regions have strict seasonality, with the vast majority of cases concentrated in July, August and September, accounting for about 80% of the total number of cases in the year. The epidemic peak in central China is from July to August, one month earlier in South China and one month later in North China. The epidemic characteristics of pigs are high infection rate, low incidence, generally recessive infection, most of them no longer relapse after the disease is cured, and become infected pigs. Generally speaking, the natural infection peak of pigs is 4 weeks earlier than the epidemic peak of Japanese encephalitis in humans.

The main source of infection of Japanese encephalitis in pigs is virus-carrying animals, in which pigs and horses are the most important animal hosts and sources of infection. The horse is the natural host of the virus, and the pig is the multiplication host and source of infection of the virus. The virus spreads continuously through the mosquito → pig → mosquito cycle. Birds are also important storage hosts for this virus. Birds can produce high titers of viremia after infection. The antibody to Japanese encephalitis virus was found in the blood of many birds in Japan, and the Japanese encephalitis virus was isolated from the nestling of heron. Except pigs and birds, cattle, sheep, bats and other animals can be infected with Japanese encephalitis virus and become the storage host and source of infection of the virus.

It is mainly transmitted by mosquitoes (Culex pipiens, Aedes albopictus, Anopheles Anopheles, etc.), the most important of which is Culex tritaeniorhynchus. Overwintering mosquitoes can transmit the virus every other year, and the virus may also be passed on to the next generation through mosquito eggs. The transmission cycle of the virus is repeated through mosquito bites between overwintering animals and susceptible animals. Pigs can also be transmitted vertically through the placenta to the fetus.

Horses, pigs, cattle, sheep, chickens and wild birds can all be infected. Horses are the most susceptible, pigs are susceptible to infection regardless of breed and sex, and young animals are the most susceptible. People are also susceptible to infection, mainly through insect bites such as mosquitoes (Culex tritaeniorhynchus). Generally speaking, the disease mainly occurs in children under the age of 10, accounting for more than 80% of the total number of patients, and most adults are recessive infections.

2. Clinical symptoms and diagnosis

The incubation period of artificial infection is generally 3-4 days. The diseased pigs showed elevated body temperature, depression, lethargy and loss of appetite. The body temperature increased to 40: 41 ℃, showing missed fever. Depressed spirit, loss of appetite, conjunctival flushing. When pregnant sows get sick, they often have sudden miscarriage, premature delivery, stillbirth or mummified fetus. Abortion often occurs in the late pregnancy, when the breast swelling, the outflow of milk, common placenta stagnation, from the vaginal flow of reddish brown or grayish brown mucus. Piglets develop spastic symptoms within a few days after birth and die, or become stiff pigs. Boar symptoms are not obvious, orchitis can occur.

In the initial stage of the sick horse, the body temperature rises, less movement and loss of appetite. In severe cases, they are unstable on their feet and their limbs are swimming. Some horses are excited and manic. Generally, the symptoms of depression, excitement and paralysis appear successively or alternately.

Japanese B encephalitis often occurs in children under 10 years old, with an incubation period of 4-21 days, usually 10-14 days. The main clinical symptoms were acute onset, fever, headache, jet vomiting, disturbance of consciousness in varying degrees after 2-3 days of fever, and central nervous symptoms such as systemic convulsion, tonic spasm or paralysis in severe patients. Central respiratory failure occurred in severe cases.

According to the clinical symptoms and pathological changes, a preliminary diagnosis can be made, and the diagnosis needs further laboratory diagnosis. Differential diagnosis should be made from pseudorabies, parvovirus, classical swine fever and other diseases.

3. prevention and control measures

Pigs were vaccinated with attenuated Japanese encephalitis vaccine 1-2 months before the epidemic season. Strengthen the feeding and management of animals, improve animal resistance, regularly do a good job in environmental disinfection, mosquito control, mosquito prevention, and reduce the incidence of epidemic diseases.

When the epidemic disease of Japanese encephalitis occurs, strict control and extinction measures shall be taken to prevent the spread of the disease. The sick animals were culled and treated innocuously. Dead pigs, aborted fetuses, placentas and amniotic fluid must be treated innocuously. Contaminated places and appliances should be thoroughly disinfected.

4. Public health and personnel protection

In rural areas and farms, it is necessary to do a good job in environmental hygiene and immunization of pigs, through the control of je in pigs, so as to reduce the epidemic of human je. Farms, veterinarians, laboratory personnel, etc., should wear protective clothing, masks, gloves and other protective equipment before coming into contact with sick animals or virus pollutants. At the end of the work, all protective equipment should be taken off on the spot, washed and disinfected, and disposable items should be treated innocuously. People of the right age and related staff in the epidemic area of Japanese encephalitis should be vaccinated with je vaccine.

(8) highly pathogenic porcine blue ear disease

Highly pathogenic porcine blue ear disease is an acute and highly fatal disease caused by mutants of porcine reproductive and respiratory syndrome (commonly known as blue ear disease) virus. The Ministry of Agriculture and Village classifies it as a kind of animal epidemic.

1. Popular characteristics

The infection rate of blue ear disease virus in pigs in China is very high, and the positive rate of antibody in pigs is 10% 88%. At present, the persistent infection of blue ear disease virus in pig farms is an important epidemiological feature of the disease. It can survive for a long time in the serum, lymph nodes, spleen, lungs and other tissues of infected pigs, and can detoxify the environment. Older pigs and breeder pigs showed invisible infection. In China, the phenomenon of virus-carrying in breeding pigs is more serious. Blue ear disease virus can often be detected from sow blood and boar semen, and the virus can be transmitted through placenta and semen. Infected sows and infected sows can show estrus disorders, such as delayed delivery, non-estrus and so on.

2. Clinical symptoms

The body temperature increased significantly to more than 41 ℃; conjunctivitis, eyelid edema; cough, asthma and other respiratory symptoms; some pigs hindquarters weakness, unable to stand or ataxia and other neurological symptoms; the incidence of piglets can reach 100%, the mortality rate can reach more than 50%, the abortion rate of sows can reach more than 30%, and adult pigs can also die.

3. Disposal of epidemic situation

Any unit or individual that discovers the occurrence of acute morbidity and death in pigs shall promptly report to the local animal epidemic prevention and control agency. After receiving the report or understanding of the clinically suspected epidemic situation, the local animal disease prevention and control agency shall immediately send personnel to the scene for preliminary investigation and verification, and collect samples for laboratory diagnosis to confirm the epidemic situation.

When the epidemic situation is suspected, the disease site / household should be isolated and monitored, the movement of pigs and their products and related articles should be prohibited, and strict disinfection measures should be carried out on their internal and external environment. Harmless treatment of sick and dead pigs, pollutants or suspicious pollutants. When necessary, the diseased pigs and the same herd pigs should be culled and treated innocuously.

After the epidemic situation is confirmed, the epidemic spot, epidemic area and threatened area shall be designated by the competent veterinary department at or above the county level. In the epidemic spot, all sick pigs and pigs in the same group shall be culled; dead pigs, excreta, contaminated feed, bedding and sewage shall be treated innocuously; and contaminated articles, vehicles, appliances, pig sheds and sites shall be thoroughly disinfected. In the epidemic area, the contaminated articles, vehicles, appliances, pig houses and sites were thoroughly disinfected; all pigs were urgently immunized with inactivated vaccine against highly pathogenic porcine blue ear disease, and epidemic surveillance was strengthened. Emergency enhanced immunization and epidemic surveillance were carried out for all pigs in threatened areas with inactivated vaccine against highly pathogenic porcine blue ear disease.

4. Prevention and control measures

Strengthen monitoring. Focus on monitoring live pigs in high-risk areas such as pig breeding farms, isolation farms, borders, recent outbreaks and frequent outbreaks. Animal disease prevention and control institutions at all levels carry out risk analysis on the monitoring results and related information, and make early warning and forecast. The laboratory designated by the Ministry of Agriculture and villages analyzed and evaluated the biological and molecular biological characteristics of the isolated strains.

Improve the quality of immunity. All live pigs were immunized with inactivated vaccine against highly pathogenic porcine blue ear disease. During the outbreak of highly pathogenic porcine blue ear disease, the inactivated vaccine of highly pathogenic porcine blue ear disease was used for emergency enhanced immunization. Animal epidemic control agencies at all levels regularly monitor the immune antibody level of immunized pigs and strengthen immunity in time according to the growth and decline of population antibody level.

Strengthen feeding and management, implement closed breeding, establish and improve various epidemic prevention systems, and do a good job in disinfection, insecticidal and rodent control.

(IX) African classical swine fever

African classical swine fever is an acute, severe and highly contagious disease caused by African classical swine fever virus. Morbidity and mortality are as high as 100%. Domestic pigs, wild boars and soft ticks infected with African classical swine fever virus are the main sources of infection. The Ministry of Agriculture and Village classifies it as a kind of animal epidemic.

1. Popular characteristics

African classical swine fever is the biggest threat to the production safety of pig industry in China. At present, the virus has been colonized in China and formed a large pollution surface, the risk of epidemic situation is very high. African classical swine fever is transmitted mainly through contact with African swine fever virus infected pigs or African classical swine fever virus pollutants (kitchen waste, feed, drinking water, enclosures, bedding, clothing, appliances, vehicles, etc.). Digestive tract and respiratory tract are the main routes of infection; it can also be transmitted by insect bites such as soft ticks. The risk of aerosol transmission of African classical swine fever is very low. Domestic pigs and Eurasian wild boars are highly susceptible, and there is no significant difference in breed, age and sex. The seasonality of classical swine fever in Africa is not obvious.

2. Clinical symptoms

Incubation period, morbidity and mortality of African classical swine fever: the incubation period varies according to the strain, host and route of infection, which is generally 19 days and the longest is 21 days. The morbidity and mortality of pigs infected by virulent strains can reach 100%; the fatality rate caused by moderately virulent strains is generally 30% 50%, and low virulent strains cause only a small number of deaths in pigs.

The clinical manifestations can be divided into the most acute, acute, subacute and chronic.

The most acute: sudden death without obvious clinical symptoms.

Acute: body temperature can be as high as 42 ℃, depression, anorexia, ear, limbs, abdominal skin bleeding, splenomegaly, eyes, nose mucus purulent secretions; vomiting; diarrhea, feces with blood. Ataxia or stiff gait, dyspnea, paralysis, convulsions and other neurological symptoms. Pregnant sows had a miscarriage. The case fatality rate can reach 100%. The course of the disease ranged from 4 to 10 days.

Subacute: the symptoms are the same as acute, but the condition is mild and the fatality rate is low. The fluctuation of body temperature is irregular, generally higher than 40.5 ℃. The case fatality rate of piglets was higher. The course of the disease ranged from 5 to 30 days.

Chronic: wavy fever, dyspnea, wet cough. Emaciated or stunted, weak and dull in color. Swelling of joints and skin ulcers. The mortality rate is low. The course of the disease ranged from 2 to 15 months.

3. Pathological changes.

The typical pathological changes are enlarged and fragile spleen, dark red to black, bleeding spots on the surface, blunt edges, sometimes marginal infarction, congestion and bleeding on the serous surface, bleeding spots on the surface of the kidney, lungs and endocardium, diffuse bleeding in the gastric and intestinal mucosa, gallbladder and bladder bleeding, enlargement of the lungs, flow of foamy fluid from the section, and bloody foam-like mucus in the trachea. The submandibular and celiac lymph nodes were enlarged with severe bleeding. Individuals of the most acute type may not have obvious pathological changes.

4. Laboratory diagnosis

The clinical symptoms of African classical swine fever are similar to those of classical swine fever, highly pathogenic porcine blue ear disease and porcine erysipelas, which must be diagnosed by laboratory testing, and serum and etiological samples of diseased pigs or pigs of the same group can be collected.

If the clinical suspicious cases are re-examined by the laboratories of provincial animal disease prevention and control institutions or the laboratories of prefectural and municipal animal disease prevention and control institutions authorized by the animal husbandry and veterinary departments of the people's government at the provincial level, if the African classical swine fever virus nucleic acid is positive, it shall be determined as a confirmed case.

5. epidemic situation disposal and prevention and control measures

At present, there is no approved vaccine for the prevention and control of African classical swine fever. Mainly rely on pig farm environmental control, pig health management, feed nutrition, feeding management, health and epidemic prevention, disinfection, harmless treatment and other aspects of biosafety measures to remove pathogens and reduce the probability of infection. For the relevant sites where suspicious and suspected epidemics occur, the competent animal husbandry and veterinary departments at the county level and the township government should immediately organize and take measures such as isolation and observation, sampling and testing, epidemiological investigation, restrictions on the entry and exit of susceptible animals and related articles, and environmental disinfection. Blockade, culling and other measures may be taken when necessary. After the epidemic situation is confirmed, the animal husbandry and veterinary departments of the people's governments at or above the county level shall immediately delineate epidemic spots, epidemic areas and threatened areas.

The designation and disposal of epidemic spots, epidemic areas and threatened areas shall be implemented in accordance with the provisions of the Emergency implementation Plan for African Classical Swine Fever (second Edition 2020).

Disinfection of pig farms in disaster areas: choose effective disinfectants and disinfection methods to carry out disinfection and sterilization work. 3% sodium hypochlorite can be used for disinfection of drinking water for pigs; glutaraldehyde of 1Rue 200mur300 or compound phenol of 1RV 100Rue 300 can be used for disinfection of empty pens and vehicles; 0.5% peracetic acid solution can be used for spray disinfection of pig house environment; 2% Rue 5% iodine preparation can be used for disinfection of pigs, and compound phenol spray of 1Rue 100Rue 300 can be used for disinfection of pigs. The gate disinfection tank can be disinfected with 1% Mel 5% sodium hydroxide solution; workers entering and leaving the disinfection channel can be disinfected by ultrasonic atomization wave disinfector or ultraviolet radiation disinfection; feces and other pollutants can be stacked and fermented or incinerated.

For the prevention and control of African classical swine fever in pig farms, it is necessary to achieve "five must and four no". The "five essentials" are: first, to reduce the number of people and vehicles from outside the pig farm entering the pig farm; second, to thoroughly disinfect the personnel and vehicles before entering the pig farm; third, to carry out "all in and all out" feeding and management of the pig farm; fourth, to isolate the newly introduced pigs; fifth, to declare and quarantine in accordance with the regulations. "four no": first, do not use hogwash to feed pigs; second, do not release pigs; third, do not buy pigs from epidemic areas; fourth, do not conceal or late report suspected epidemics.

In areas where African classical swine fever has occurred, attention should be paid to landfill disinfection to prevent secondary pollution caused by floods.