Teschovirus Encephalomyelitis Cases in Haiti
HAITI - Since January 2009, a teschovirus PTV-1 serotype has been circulating in pigs in Haiti.The American Association of Swine Veterinarians, (AASV) reports that the virus has been identified by USDA's Foreign Animal Disease Diagnostic Lab at Plum Island.
While the virus does not affect humans, it is causing important losses to Haiti pig producers resulting in acute encephalomyelitis in pigs with an infectivity of 30 to 40 per cent and a lethality of 40 to 50 per cent, according to field observations. Surviving animals often remain paralysed.
Citing a report from the French Agricultural Research Centre for International Development (CIRAD), AASV says that the disease is widespread and has reached the border with the Dominican Republic (DR), threatening the DR as well as other countries of the region. The contamination of pigs occurs by ingestion or inhalation of products contaminated by faeces, urine or oral secretions of infected animals, the virus being very resistant in the environment.
The DR already reinforced surveillance at borders and a workshop is organized the second week of August to inform field agents in charge of Classical Swine Fever about this new threat, with support from Haitian veterinary officers.
The AASV adds that 11 serotypes of porcine teschovirus (PTV) are recognised, most resulting in sub-clinical or mild disease in pigs, the only known host. Highly virulent strains of PTV-1, however, cause teschovirus encephalomyelitis. Pigs of all ages are susceptible and clinical signs include fever, anorexia, depression and incoordination, followed by painful hypersensitivity, paralysis and death within three to four days. Muscle tremors, stiffness or rigidity, nystagmus, seizures, changes in or loss of the voice, opisthotonos and clonic spasms of the legs may be seen. Although mild cases may recover, progressive paralysis, beginning in the hindquarters, may be observed in the advanced stages with death in up to 90 per cent of the cases resulting from respiratory paralysis. There are no characteristic gross lesions.
Further Reading
- | You can find out more about PTV from the Center for Food Security and Public Health (CFSPH) at Iowa State University by clicking here. |