Japanese Encephalitis is caused by a virus. Japanese encephalitis virus (JEV) is a mosquito-borne Flavivirus that is closely associated to West Nile and St. Louis encephalitis viruses. Mosquitoes become infected by feeding on domestic pigs and wild birds infected with the Japanese encephalitis virus. Infected mosquitoes then transmit the Japanese encephalitis virus to humans and animals during the feeding process. The Japanese encephalitis virus is amplified in the blood systems of domestic pigs and wild birds. Japanese encephalitis virus is NOT transmitted from person-to-person.
Japanese Encephalitis illness arises throughout most of Asia and is the most common cause of encephalitis in that region. Other than sporadic travel-related cases, Japanese encephalitis (JE) has not been notorious in Africa, Europe or the Americas. Other places, disease patterns vary with rainy seasons and irrigation practices. Japanese encephalitis outbreaks are usually circumscribed and do not cover large areas. They usually do not last more than a couple of months, dying out after the majority of the pigs amplifying hosts have become infected. Birds are the natural hosts for Japanese encephalitis.
Epidemics arise when the virus is brought into the peridomestic environment by mosquito bridge vectors where there are pigs, which serve as amplification hosts, infecting more mosquitoes which then may contaminate humans. Most Japanese Encephalitis virus infections are soft or without clear symptoms, but approximately 1 in 200 infections results in severe disease characterized by fast onset of high fever, headache, neck stiffness, disorientation, coma, seizures, spastic paralysis and death. Anyone can get Japanese encephalitis, but some people are at an increased risk active-duty military deployed to areas where the disease is common.
Travelers to rustic areas where the disease is familiar. Travelers with widespread outdoor, evening, and nighttime exposure in rural areas, such as might be experienced while bicycling, camping, working outdoors, or sleeping in unscreened structures without bed nets, may be at high risk even if their trip is brief. There is no specific treatment for Japanese encephalitis and treatment is supportive. Anticonvulsants to manage seizures, ventilation support, and feeding are the standard treatments. Mannitol is used to decrease intracranial pressure when needed. Use an electric mat to vaporise insecticide overnight. Burning a mosquito coil is an alternative.
