Nipah Virus – An Overview
INTRODUCTION:
Nipah Virus is a newly emerging zoon-osis that causes a severe disease in both animals and humans. This virus was first identified in Malaysia and Singapore . At that time, it was primar-ily caused in pigs and through them got transferred to humans.Nipah virus (NiV) is a member of the fami-ly Paramyxoviridae, genus Henipavirus. The natural host of the virus is fruit bats of the Pteropodidae Family, Pteropus genus.
NiV was initially isolated and identified in 1999 during an outbreak of encepha-litis and respiratory illness among pig farmers and people with close contact with pigs in Malaysia and Singapore. Its name originated from Sungai Nipah, a village in the Malaysian Pen-insula where pig farmers became ill with encephalitis. Given the related-ness of NiV to Hedra Virus, bat species were quickly singled out for investiga-tion and flying foxes of the ge-nus Pteropus were subsequently iden-tified as the reservoir for NiV
In the 1999 outbreak, Nipah virus caused a relatively mild disease in pigs, but nearly 300 human cases with over 100 deaths were reported. In 2001, NiV was again identified as the causa-tive agent in an outbreak of human disease occurring in Bangladesh. Ge-netic sequencing confirmed this virus as Nipah virus, but a strain different from the one identified in 1999.
Structure:
Nipah virus is a newly emergent, bat-borne paramyxovirus found in South-east Asia that causes encephalitis in humans with 40 to 90% lethali-ty .There are no vaccines or antiviral therapeutics approved for human use .Nipah virus has a single-stranded, negative-sense RNA genome that is encapsidated by the nucleoprotein (N) and transcribed and replicated by the polymerase protein (L). The phospho-protein (P) plays an essential role as a polymerase cofactor, enhancing poly-merase processivity and allowing the encapsidation of the newly synthesized viral genomes and antigenomes. In these roles, P serves as a tether be-tween the polymerase and its template and also serves as a chaperone for nas-cent, RNA-free N, termed N0, prevent-ing it from nonspecifically binding host RNA.