Nipah virus-Unfolded mystery
heNipah virus, an unsual paramyxovirus turned out to be one of the most preveiling concern in zoogenesis as well as microbiology.It has been identified as etiological agent of outbreak of severe febrile encephalitis associated with human deaths was reported in Peninsular Malaysia beginning in late September 1998. However, in subsequent NiV outbreaks, there were no intermediate hosts. In Bangladesh in 2004, humans became infected with NiV as a result of consuming date palm sap that had been contaminated by infected fruit bats.
Electron microscopic studies demonstrated unique characteristics which indicate this virus belongs to paramyxovirus,a family s typically possesses a single-stranded nonsegmented RNA genome of negative polarity that is fully encapsidated by protein. Virus particles vary in size from 120 to 500 nm. The paramyxovirus envelope contains two transmembrane glycoproteins, HN (hemagglutinin/ neuraminidase)] and a separate fusion (F) protein. Thin-section EM studies of infected cells revealed typical “herringbone” nucleocapsids within cytoplasmic inclusions and incorporated into virions budding from the plasma membrane. . Serologic studies also suggested that Nipah virus infection occurred in dogs, cats, and bats including human which have direct contact with pigs. The most notable illness in pigs which transmitted to human and infect respiratory tract followed by other parts of body includes CNS. Infection was most prominent in the central nervous system, where a diffuse vasculitis was noted in the cerebral cortex, Necrosis observed in many areas of brain. viral inclusions with a melted-tallow appearance were seen in the affected neurons and other parenchymal cells. This leads to severe damage of other organs like kidney, heart and spleen.
There is no such efficient vaccine against it. Mortality rate is 70%. The drug ribavirin has been shown to be effective against the viruses in vitro, but human investigations to date have been inconclusive and the clinical usefulness of ribavirin remains uncertain.apart from it, Passive immunization using a human monoclonal antibody targeting the Nipah G glycoprotein has been evaluated in the post-exposure therapy in the ferret model and found to be of benefit.