New Delhi: The Indian Council of Medical Research (ICMR) in collaboration with the National Institute of Virology, Pune, has developed IgM and IgG ELISA primary diagnostic tools for Nipah virus (NiV) screening. The NiV is a zoonotic paramyxovirus that causes fatal encephalitis in humans.

Enzyme-Linked Immunosorbent Assay (ELISA) is a safe, sensitive, specific, and affordable diagnostic tool that can be used during the screening of large-scale epidemiological investigations. The development and evaluation of IgM and IgG ELISA for screening serum samples of NiV in suspected cases would also help in planning public health interventions, ICMR scientists have underlined in a study.

An IgM capture (MAC) ELISA and an indirect IgG ELISA were developed using NiV antigen to detect IgM and IgG antibodies against NiV in human sera. The sensitivity, specificity, and cross-reactivity of the assays were evaluated using NiV IgM, IgG positive, negative human sera and measles, mumps, rubella, Crimean-Congo haemorrhagic fever, Kyasanur forest disease IgM, IgG positive sera, respectively, the study noted.

The scientists have also claimed that the developed anti-NiV IgM and IgG ELISAs have shown a specificity of 99.28 per cent and sensitivity of 100 per cent compared to reference tests from the Centers for Disease Control and Prevention, USA. Assays demonstrated a negative predictive value of 100 per cent and positive predictive value of 90 and 93.94 per cent for anti-Nipah IgM ELISA and IgG ELISA respectively with a test accuracy of 99.33 per cent.

Timely diagnosis of NiV is crucial for the management of cases, which could prevent the further spread of infection in the community. IgM ELISA can be used as a primary diagnostic tool followed by polymerase chain reactions, it claimed.