Monsoon Diseases: Here are The Common Causes That are Responsible for Japanese Encephalitis

A viral disease infecting humans and animals, Japanese encephalitis (JE) is transmitted by mosquitoes in humans and cause an inflammation of the membranes around the brain. A leading cause of viral encephalitis in Asia, Japanese encephalitis has been found from the western pacific region in east to Pakistan in the west and from Korea in the north to Papua New Guinea in the south.

The viral disease Japanese encephalitis is caused by the mosquito-borne Japanese encephalitis virus, also known as JEV. The flavivirus usually affects the membranes around the brain, causing inflammation in the brain.

The flavivirus, a common cause of Japanese encephalitis, can affect both humans and animals. The virus is passed from animals to humans through the bite of an infected mosquito. While mosquitoes act as the vectors to transmit flavivirus from infected animal or bird by sucking their blood and passing the virus to humans through their bite, pigs and wading birds are the main carriers of the Japanese encephalitis virus. The Japanese encephalitis cannot be passed from person to person.

The mosquito-borne flavivirus, responsible for the transmission of Japanese encephalitis, belongs to the same genus as dengue, yellow fever and West Nile viruses. JEV is usually spread from the bites from infected mosquitoes of the Culex species (mainly Culex tritaeniorhynchus).

The mosquitoes, which transmit Japanese encephalitis flavivirus from infected animals and birds to humans, usually breed in rural areas. Their breeding usually happens in are having flooded rice fields or marshes. However, infected mosquitoes have also been found in urban areas. These mosquitoes usually feed between sunset and sunrise, which is the night time.

While the symptoms of the infection caused by Japanese encephalitis virus are mild, resulting in fever and headache, in severe cases, the symptoms may include headache, vomiting, fever, confusion and seizure, sometimes also in spastic paralysis and death.

The enveloped Japanese encephalitis virus is closely related to the West Nile virus and the St. Louis encephalitis virus. In these viruses, the positive-sense single-stranded RNA genome is packaged in the capsid which is formed by the capsid protein. It has also been noted that Japanese encephalitis virus infects the lumen of the endoplasmic reticulum, resulting in rapid accumulation of substantial amounts of viral proteins.

According to World Health Organisation, while there is no antiviral treatment for patients with Japanese Encephalitis, there are a number of safe and effective JE vaccines available to prevent disease.