African swine fever has been attracting attention to the situation in China. Almost 4 million pigs have been discarded since the disease was identified. Highly contagious, there is no treatment, much less a cure, the virus is causing fear in the global market. The disease affects pigs and wild boars and is not transmitted to humans. The first case in the world was identified in Africa, in the 20th century, among wild pigs. In 1957, the disease was introduced into Europe, in Portugal, through aircraft food waste containing products derived from swine contaminated with ASF. In Brazil, there were cases in 1978, in the Metropolitan Region of Rio de Janeiro. The country eradicated ASF and has been considered free for 35 years.
Since September 2018, China has faced a problem that has now reached epidemic status. The Asian country had the largest pig herd in the world (428 million heads), the largest production (54 million tons), the largest consumer market (55 million tons) and the highest import rate (1.56 million tons). tons). To give you an idea of how gigantic these numbers are, consumption alone is 18 times greater than that of Brazil, for example. So far the disease has spread to other countries, such as Hungary, Mongolia, Vietnam, Cambodia and Hong Kong.
The virus and transmission
African Swine Fever is caused by a DNA virus that already has 24 different genotypes identified. Most of them are highly contagious and lead to high mortality rates. Proliferation is rapid. The main form of transmission is through direct contact between pigs or when these animals ingest contaminated pork products or carcasses of dead pigs that remain in the environment. A less common route is by ticks passing from one animal to another. The virus persists in blood and tissues even after death, making it easier to spread. Refrigerating and maturing meat does not inactivate the virus, which can remain active for 11 days in feces, 15 weeks in refrigerators and up to 6 months in cured or smoked sausages.
The disease is mandatory for notification to international bodies. A vaccine is already under development by the USDA, the US government's agricultural agency. However, while it is not approved and commercialized, in cases of disease outbreaks, the sanitary slaughter of animals and the appropriate disposal of carcasses are mandatory.
PsA symptoms
The incubation period for the disease is 4 to 19 days. In the acute form, the virus causes redness and hemorrhages in the skin, anorexia, apathy, cyanosis and lack of motor coordination within 24 to 48 hours before death; increased respiratory rate; vomiting, diarrhea (sometimes bloody) and eye secretions. Less severe cases bring fever, lack of appetite, depression, respiratory signs and miscarriages, and can be easily confused with other diseases.
Tests to identify are carried out in official laboratories with lymph node, kidney, spleen, lung, blood and serum samples.
Care in Brazil
Brazil has a surveillance system for hemorrhagic syndromes that includes laboratory tests for PSA as a differential diagnosis for Classical Swine Fever (CSF). The Ministry of Agriculture, Livestock and Supply (Mapa) has implemented precautions at borders and when importing agricultural products and food from countries where ASF is occurring.
In the event of an outbreak in the country, disease control actions include the rapid sanitary slaughter of all pigs; the proper disposal of carcasses and thorough cleaning and disinfection of facilities; the designation of the infected zone, with control of the movement and transit of pigs; and detailed epidemiological research, tracking possible sources of infection and spread, in addition to surveillance of the infected area and the surrounding area.
Cases of Classical Swine Fever were recently identified in the Northeast. All animals were slaughtered. PSC is caused by a different virus from PSA, being less severe and also not transmitted to humans.
Post: Marina Carvejani
Author: Eliza Maliszewski
Source: agrolink
