Russia issued a warning about the possibility of rise in cases of West Nile Virus  infections this autumn because mild temperatures and heavy precipitation are the favourable circumstances for mosquitos carrying the virus.

• More than 80% of West Nile fever cases are registered in the southwest Russia.
• According to the reports, human cases of the mosquito-borne West Nile virus were increasing in North Dakota region of Russia.
• So far, five people have confirmed cases.

It is a single-stranded RNA virus causing West Nile fever. Virus is the member of family Flaviviridae, which also comprises the Zika virus, dengue virus, as well as yellow fever virus. This virus is primarily transmitted through mosquitoes and mostly by species of Culex. Primary hosts of the virus are birds. Genetically, the virus is related to the Japanese encephalitis family. Humans and horses both exhibit disease symptoms from this virus. First human case of the disease was reported in 1937 in Uganda and now it is the leading cause of mosquito-borne disease in continental United States.

West Nile virus was originated in Africa. It has now spread to Europe, Asia, and North America. Virus is mostly transmitted by mosquito bites, causing a deadly neurological condition in humans.

Most of the West Nile virus cases occur during mosquito season, starts in the summer and lasts until the fall.

Majority of people (8 out of 10) infected with West Nile virus do not exhibit any symptoms. Some infected people develop fever along with symptoms like headache, body aches, joint pains, rash, vomiting or diarrhoea.