Social history of viruses of encephalitis, of which 105 were fatal, were recorded. A new paramyxovirus was discovered in a victim's brain; it was named Nipah virus, after the village where he had lived. The infection was caused by a virus from fruit bats, after their colony had been disrupted by deforestation. The bats had moved to trees nearer the pig farm and the pigs caught the virus from their droppings. Several highly lethal viral pathogens are members of the "Filoviridae". Filoviruses are filament-like viruses that cause viral haemorrhagic fever, and include the Ebola and Marburg viruses. The Marburg virus attracted widespread press attention
West Nile virus West Nile virus West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the family Flaviviridae, specifically from the genus "Flavivirus", which also contains the Zika virus, dengue virus, and yellow fever virus. West Nile virus is primarily transmitted by mosquitoes, mostly species of the genus "Culex", but ticks have also been found to carry the virus. The primary hosts of WNV are birds, so that the virus remains within a "bird-mosquito-bird" transmission cycle. Like most other flaviviruses, WNV is an enveloped virus, but has icosahedral symmetry. Flavivirus envelopes consist of