|Source of the outbreak(s) or origin of infection
See the epidemiological comments
||The first case of BSE in Brazil was notified on 7 December 2012, after the diagnosis was confirmed by the OIE Reference Laboratory at Weybridge / United Kingdom (Animal Health and Veterinary Laboratories Agency - AVHLA).
The event concerns a native cow reared for beef calves. The animal was born in 1997, after the feed ban on use of ruminant protein in ruminant feed in Brazil, established in 1996. Epidemiological investigation showed that lifelong the animal was only fed with fodder and mineral supplement, rearing system that is not favorable to the occurrence of classical BSE and which concerns approximately 95% of Brazilian beef cattle.
The case showed characteristics unusual for BSE, such as acute course until death (within less than 24 hours) and advanced age of the animal (around 13 years). Samples were taken for the diagnosis of rabies and differential diagnosis, since the farm was in an area endemic for herbivores’ rabies. Therefore, the sample was included into the surveillance system for neurological syndromes, as recommended by the national protocol.
Epidemiological investigation conducted after the positive result obtained by immunohistochemical test by the National Reference Laboratory, LANAGRO, Recife/PE, followed provisions in point 3.b, Article 11.5.3 of the OIE Terrestrial Animal Health Code. All cohort animals born during the 12-month period before and after the case was born were identified and kept under movement restrictions and official veterinary surveillance. These were cows around 15 years old and in good health conditions which were humanely euthanized on the premises where they were and their carcasses were buried in a deep pit in appropriate premises. Samples from these animals were tested for BSE at LANAGRO Recife/PE Laboratory and all resulted negative.
Considering the aforementioned information, the results of the epidemiological investigation conducted by the Brazilian veterinary services and the AVHLA report that states that “Although the poor quality and the indeterminate fixation history of the sample compromises interpretation, even so we note that the sample appears to have some characteristics of H-Type rather than L or C-Type of BSE”, the Brazilian veterinary services believe that this is a case of atypical BSE (rare and spontaneous). Furthermore, it is important to highlight that this animal did not enter the meat-processing chain, having been buried on the farm where it died; therefore, it did not represent any risk of contamination.
Based on these results, the Animal Health Department / SDA / MAPA considers the investigation on the BSE case in Brazil closed.
Note by the OIE Animal Health Information Department: At present time, the OIE does not yet recognise an atypical form of BSE as a distinct entity for the purpose of its international standards; therefore, it is not mentioned in the OIE Terrestrial Animal Health Code, which does not distinguish between different forms of BSE.