3b). its potential SBC-115076 as an effective tool for detecting NiV neutralizing antibodies under BSL2 containment with higher speed, level of sensitivity and security as compared to the conventional NiV serum neutralization test. strong class=”kwd-title” Keywords: Nipah, Henipavirus, Pseudotype, Neutralization, Analysis, Biosafety 1.?Intro Nipah disease (NiV) is a highly pathogenic paramyxovirus that emerged while the causal agent of respiratory disease in pigs and an acute febrile encephalitis in humans working in the pig market in Malaysia and Singapore in 1998 (Chua et al., 2000). NiV is definitely classified in the new genus em Henipavirus /em , based on unique genetic characteristics unique from additional paramyxoviruses (Eaton et al., 2006, Eaton et al., 2007), together with Hendra disease (HeV) which has caused repeated incidences of severe respiratory and neurological diseases among horses and humans in Australia since 1994 (Bishop and Broder, 2008, Murray et al., 1995). Organic NiV infections were also confirmed in dogs, cats and horses. Further NiV outbreaks have occurred in Bangladesh and India almost every yr since 2001 (Bishop and Broder, 2008, Chadha et al., 2006, Harcourt et al., 2005, Hsu et al., 2004). Henipavirus reservoirs look like several varieties of fruit bats, primarily of the genus em Pteropus /em . During the NiV outbreak within the Malay Peninsula, humans and other varieties are presumed to be infected through an intermediate varieties such as pigs (Eaton et al., 2006). On the other hand, in the NiV outbreak in Bangladesh in 2004, involvement of animals other than fruit bats was not confirmed, indicating direct transmission from bats to humans (Hsu et al., 2004, Luby et al., 2006). Human-to-human transmission has also been suggested based on the epidemiological studies carried out in Bangladesh (Gurley et al., 2007a, Gurley et al., 2007b). The presence of antibodies against NiV or NiV-like viruses in fruit bats have been reported in Thailand (Wacharapluesadee et al., 2005), Cambodia (Olson et al., 2002, Reynes et al., 2005), Indonesia (Sendow et al., 2006), Madagascar (Lehle et al., 2007), Ghana (Hayman et al., 2008) and China (Li et al., 2008). For safe and quick serological analysis of NiV illness, several enzyme-linked immunosorbent assays (ELISAs) have been developed (Daniels et al., 2001). Even though specificities of these ELISAs are fairly high, they still yield false positive results. This means that confirmatory analysis is required when an animal is suspected of being infected with NiV by ELISA. The serum neutralization test, which detects neutralizing antibodies against the viral fusion (F) and/or attachment (G) glycoproteins is regarded currently as the gold standard for serological analysis, and is approved as the research standard of the World Organization for Animal Health (OIE) (OIE, 2008). Although cross-reactivity is present between NiV and HeV by serum neutralization test, they can be differentiated when sera are tested against both viruses simultaneously (Daniels et al., 2001). Due to the highly pathogenic nature of NiV and HeV and the absence of any restorative or prophylactic actions, both are classified as biosafety level 4 (BSL4) pathogens and serum neutralization test using live disease must be carried out SBC-115076 under BSL4 SBC-115076 conditions (OIE, 2008). These security concerns possess prompted the development of a system for detecting neutralizing antibodies against NiV without using live infectious disease. Probably one of the most encouraging systems is based on vesicular stomatitis disease (VSV) G*, a recombinant VSV whose G gene was replaced from the green fluorescent protein (GFP) gene (Lawson et al., 1995, Takada et al., 1997). In this study, a serum neutralization test using VSV-based pseudotyped disease possessing NiV-F and G was developed. The results of the neutralization test using VSVCNiVCGFP was found to be well correlated with those acquired using live NiV. Using a 50% reduction in IL1A VSVCNiVCGFP infected cells as the cut-off for neutralization, this assay shown its potential as a more rapid and sensitive method than the standard serum neutralization test using live-NiV. Furthermore,.