Nipah virus is a member of the family Paramyxoviridae, genus Henipavirus. The virus was initially isolated and identified in 1999 during an outbreak of encephalitis and respiratory illness among pig farmers and people with close contact with pigs in Malaysia and Singapore. In the 1999 outbreak, the virus caused a relatively mild disease in pigs, but nearly 300 human cases with over 100 deaths were reported. In 2001, Nipah was again identified as the causative agent in an outbreak of human disease occurring in Bangladesh. In the same year, another outbreak was identified retrospectively in Siliguri in West Bengal. (IN PIC: Only a few patients are seen at Perambra Taluk Hospital after a nurse, Lini, right, died of Nipah virus. / Express Photo by TP Sooraj)