Nipah virus (NiV) infection is a zoonotic disease that is transmitted from the natural hosts- fruit bats- to humans either directly, or indirectly through other hosts like pigs. Direct transmission occurs by consumption of fruit or date sap contaminated by infected fruit bats. Indirect transmission (through an intermediate host) is thought to occur through aerosolized respiratory secretions of infected animals. Besides, direct human-to-human transmission has also been documented where hospital workers caring for diseased individuals or visitors were infected.
Infection with Nipah virus is associated with encephalitis (inflammation of the brain). After exposure and an incubation period of 5 to 14 days,illness presents with 3-14 days of fever and headache, followed by drowsiness, disorientation and mental confusion. These signs and symptoms can progress to coma within 24-48 hours. Some patients have a respiratory illness during the early part of their infections, and half of the patients showing severe neurological signs showed also pulmonary signs.