African swine fever is a viral disease characterized by high contagiousness and acute course. It can cause the imminent death of the entire pig population. Initially, the disease affected wild boars, but subsequently the virus began to spread to domestic pigs.
General characteristics of the disease
The African plague is also known as Montgomery disease - by the name of the researcher who proved its viral nature. This is an infectious process in which inflammatory processes develop, a fever occurs, and the blood supply to the internal organs stops.
The disease-causing DNA-containing virus of the Asfarviridae family spreads to the entire population, regardless of the age of the pigs.
In individuals who died from this disease, pathological changes in the body are observed:
- multiple lesions of connective tissue;
- numerous sources of hemorrhage;
- severe pulmonary edema;
- an increase in the size of the spleen, kidneys, and liver;
- serous hemorrhagic fluid in the respiratory system and in the stomach;
- the content of blood clots in the lymph.
The virus that causes this serious illness is resistant to external conditions. It survives temperature extremes, multiplies upon drying, crystallization and decay. The virus is also resistant to formalin and an alkaline environment, but it is sensitive to acids.
In pickles and smoked meats, this virus is able to persist for several weeks or months. In feces, it remains active for about 160 days, in urine - up to 60 days. In soil, the virus can persist for 180 days, in bricks and wood - from 120 to 180 days. It remains in meat for about 5-6 months, in bone marrow - up to 6-7 months.
The first time a case of this formidable disease was recorded in 1903 in South Africa. The infectious process spread to wild boars. The disease subsequently spread to many African countries in southern Sahara.
In the mid-twentieth century, a case of African plague was recorded in Portugal. This happened after meat products from Angola were brought into the country. Subsequently, the infectious process spread to Spain, Cuba, France, Holland, and Malta.
In Russia, as well as Ukraine, Georgia, Armenia and Abkhazia, African swine fever was first detected in 2007.
The statistics of outbreaks of African plague over the years are as follows:
- Kenya - 1921;
- Portugal - 1957, as well as 1999;
- Spain - 1960;
- France - 1964, as well as 1967 and 1974;
- Italy - 1967, 1969, 1978-1984 and 1993;
- Cuba - 1971;
- Malta - 1978;
- Dominican Republic - 1978;
- Brazil - 1978;
- Belgium - 1985;
- Holland - 1986;
- Russia - 2007;
- Georgia - 2007;
- Armenia - 2007
Analyzing the causes of the rapid spread of infection, the researchers concluded that in most cases contaminated food waste contributes to this.
In Russia, the plague was brought from Georgia. In turn, this virus has spread in Georgia due to the improper use of waste from international vessels that transported infected meat and products from it. The media reported that the bodies of animals that had died in this country were found in ordinary landfills, river banks and on the coast of the sea.
In areas that are considered to be stationary-dysfunctional in African swine fever, the frequency of outbreaks is observed: in Africa this viral process occurs every 2-4 years, in Europe - after 5-6 years.
Currently, this pig infectious disease is registered in 24 countries.
Virus transmission methods
This disease affecting domestic pigs is transmitted in the following ways:
- as a result of close contact of a sick animal with a healthy one: infection occurs through the oral cavity, skin, mucous membranes of the eyes;
- through contaminated food waste, as well as equipment intended for slaughtering pigs;
- from domestic animals, birds, rodents, insects and people who were in the infected territory - slaughterhouse or warehouse;
- through the bite of a tick-carrier virus;
- through vehicles that have been contaminated when transporting sick pets;
- through food waste, which is added to the feed of pigs, without first processing them accordingly.
The duration of the incubation period of the disease is about 5-10 days.
For the human body, this disease is not dangerous, since it is not sensitive to the virus of this type. However, a person is able to act as a virus carrier and infect pigs in contact with them.
Symptoms of African swine fever
The disease can occur in three forms:
- Lightning fast. In this case, the disease develops for 2-3 days and inevitably ends in the death of an infected animal.
- Sharp. This form of the disease is characterized by severe clinical manifestations.
- Chronic. This form is weakly manifested, is very rare. Most often, a similar species of African plague is observed among wild boars.
For this pathology, the following manifestations are characteristic:
- an increase in body temperature to 42 degrees, such indicators hold until the moment of the death of the animal;
- general depression;
- weakness;
- cough;
- serous conjunctivitis;
- increased thirst;
- lack of appetite;
- purulent masses from the nose and eyes;
- severe shortness of breath;
- paresis of the hind limbs;
- vomiting
- fever;
- swollen lymph nodes;
- exhaustion;
- discoloration of the skin on the abdomen and under the chest to red or dark purple;
- constipation or bloody diarrhea;
- motor impairment;
- point hemorrhages in the lower abdomen, neck, ears.
Sick individuals are clogged into the far corner of the barn, constantly lying on their sides. The tail of infected pigs spins. If African plague affects pregnant sows, they have a miscarriage.
Some individuals can survive, but they remain carriers of the virus for a long time, and therefore threaten other animals. Immunity in this case is not produced: pigs that have undergone African plague, get it again.
Diagnostic Methods
African swine fever can be detected by the characteristic symptoms of this infectious process, which appear externally.
The diagnosis is made comprehensively, based on laboratory research data, as well as the results of pathological anatomical studies. In the diagnostic center, samples of the lungs, spleen, lymph nodes, blood and its serum are examined.
To identify the pathogen using methods of PCR, hemadsorption, fluorescent antibodies.
Ways to solve the problem
The African swine fever virus is spreading at a high rate. Conducting therapeutic measures is prohibited, the only way out is the complete destruction of infected individuals. An adequate treatment for pigs that are affected by African plague does not currently exist.
With the spread of the infectious process, it is necessary first of all to determine the boundaries of the source of infection and declare a quarantine regime.
All individuals infected with African plague must be destroyed by the bloodless method. The territory where slaughter of animals infected with the virus is planned should be isolated.
The bodies of dead and destroyed pigs, as well as their livelihoods, residues of feed and equipment are burned. The same must be done with feeders, partitions, dilapidated rooms. The resulting ash must be mixed with lime and bury in the ground. Depth must be at least 1 m.
All rooms in which animals stayed must be treated with special solutions. You need to do this 3 times, with an interval of 3-5 days. For disinfection use a solution of bleach, sodium hypochloride.
At all pig farms within 25 km of the infection zone, livestock are slaughtered, even if the pigs are healthy.
Quarantine after the detection of African swine fever lasts at least 40 days. During this period, it is forbidden to export any products received from animals (even if they were not obtained from pigs) outside the zone. Within six months after the outbreak of infection, the export and sale of any agricultural plant products is prohibited.
Activities related to the eradication of the African swine fever epidemic should be provided by veterinary services.
Prevention
There is currently no vaccine that can protect the stock from African swine fever. Work in this direction is underway, but they are experimental in nature. Scientists note that in the next 10 years, a vaccine against this viral disease will not be invented.
Prevention measures exist that can minimize the risk of an outbreak of African plague. These include:
- timely inspection of the livestock by a veterinarian and vaccination against classical plague;
- heat treatment of feed, their purchase only from reliable manufacturers;
- proper organization of processes for the disinfection of manure and sewage, disposal of animal corpses;
- organization of fencing of livestock farms;
- a ban on feeding animals food waste and confiscated materials;
- keeping pigs in fenced areas and excluding the possibility of their contact with the livestock of other owners, as well as with domestic animals, birds, insects;
- insulated equipment of the slaughter area from livestock complexes;
- cleaning the territory of the economy and surrounding areas from garbage and manure;
- limitation of free-range pigs;
- preventing the importation into the territory of the pig farm of untreated implements, as well as vehicles that have not undergone special processing;
- periodic disinfection of pig farm territories, warehouses with feed, treatment from parasites;
- purchase of pigs only by agreement with the State Veterinary Service.
If you suspect an outbreak of African plague among the livestock of pigs, you must immediately report this to the appropriate authorities - the sanitary and epidemiological station.
Preventive measures do not provide complete protection against the spread of the virus, but significantly reduce this risk.
Virus Detection Notice and Responsibility for Concealing Information
If an outbreak of African swine fever is detected among the livestock, it is necessary to immediately inform the sanitary and epidemiological station about this.
For the concealment of information about a sudden death or simultaneous mass diseases of animals, liability is imposed in the form of an administrative fine. For citizens, its size is 3,000-4,000 rubles, for officials - from 30,000 to 40,000 rubles, for legal entities - from 90,000 to 100,000 rubles.
Administrative punishment is also provided for violation of the quarantine rules and prescribed recommendations regarding the handling of potentially hazardous waste (animal bodies, feed, premises).
Watch a popular science film about the origin, distribution and danger of this disease of pigs, which has become a real scourge of farming of the XXI century:
African swine fever is a dangerous domestic animal disease that causes massive mortality. A person can act as a carrier of the virus of this disease, but it does not affect his body in any way. The African plague requires drastic measures: bloodless slaughter of all infected and healthy individuals and the organization of a quarantine regime.