Indigineously developed ELISA testing kits for Coronavirus have been found to be sensitive and specific for the detection of the COVID19 antibodies in human serum samples and can used for determining infection exposure among the general population, s study said.
The COVID19 kit may be used to detect exposed immune protected individuals, stated the study conducted by the scientists of the Indian Council of Medical Research along with other collaborators and the rsult published in the Indian Journal of Medical Research.
ELISA testing kit was found to be 97.9 percent specific, 92.37 percent sensitive, robust and reproducible. The negative and positive predictive values were 94.44 and 98.14 respectively, it mentioned.
Indian Council of Medical Research has been conducting a survey to assess the proportion of population exposed to COVID19, including asymptomatic cases as a part of which ELISA based antibody tests would be used for data collection.
Scientists highlighted that for surveillance of the emerging viruses, serological assays have been widely recommended. Several IgG/IgM ELISA test kits for Coronavirus are in varied stages of development.
However, approved and validated SARS CoV 2 serological assays are lacking for case detection and are not included in World Health Organisation's laboratory testing guidelines for Coronavirus.
Due to non-availability of an indigenous, approved and cost effective test kit, an in-house ELISA was developed and validated for the detection of anti SARS CoV 2 human IgG antibodies, the study said.
A total of 513 blood samples were tested by ELISA for Coronavirus.
Our findings suggested that this indigenous anti SARS CoV 2 human IgG-ELISA was sensitive and specific for the detection of the IgG antibodies among individuals who have been exposed to COVID19 infection, the research hghlighted.
It can be used for ascertaining the seroprevalence against SARS CoV 2 in an epidemiological and population studies, it said.
ELISA will be helpful in screening industry workers, healthcare workers and among others. The use of whole cell antigen instead of recombinant nucleocaspid antigen or spike protein antigen provided a broad sensitivity to the assay. However, the assay performances needs to be assessed in a large cohort of related human coronaviruses, the study added.
Such kits can be produced at low cost, are affordable and easy to use in resource limited settings.