Japanese B Encephalitis

Japanese B encephalitis is caused by a virus found in South Asia, it is transmitted by mosquitos and presents as reproductive problems.

Japanese B encephalitis is caused by a virus transmitted by mosquitos. The disease is confined to a large area of southern Asia. It can affect most domestic animals and produces encephalitis in humans. Pigs are a significant source of infection.

Sows

• Mummified fetuses.
• Stillbirths.

Boars 

• Infertility.
• Testicular degeneration.

Nursing piglets

• Subcutaneous edema.
• Hydrocephaly.
• Weak piglets.
• Neurological symptoms in piglets - attacks and seizures.

Nursery and fattening

• No clinical signs. 

• Presence of  mosquitos.
• Susceptible pigs.
• Other species that act as reservoirs of the virus.

• Lab tests of stillbirths and of testes from affected boars.
• Definitive diagnosis requires tissue culture virus isolation, and serum antibodies from stillbirths, usually using ELISA.
• Differentiate from other similar reproductive problems as those caused by parvovirus, Aujeszky's disease, porcine reproductive and respiratory syndrome, some strains of influenza, classical swine fever and some enteroviruses. 

• There is no effective treatment.
• Vaccination.