A comparative study on fourth generation ELISA and rapid assay for diagnosing HIV infection in the high risk group

Abstract

Background: Enzyme linked immunosorbent assay (ELISA) is a widely employed method for detecting HIV. Following its successful detection of HIV, the fourth generation ELISA was approved by FDA. The advantage of the FDA approved fourth generation ELISA is it detects p24 antigen, HIV 1&2 antibodies simultaneously and that too 5-7 days prior to conventional tests so that it detects HIV seroconversion earlier reducing its further spread. Methods: The study was conducted in a tertiary level medical centre after obtaining ethical approval. 200 patients from high risk group and their contacts were selected after a thorough physical examination and tests were done using fourth generation ELISA and rapid assay and these results were compared. Results: As per our observations, the percentage of patients tested positive by fourth generation ELISA out of 200 subjects was 37% and negative was 63%. The detection rate of HIV positivity by rapid assay in high risk group was 11% and negative was 89%. The detection rate was also higher with fourth generation ELISA when various other parameters were compared. Conclusions: In this study, the percentage of HIV positivity detected by fourth generation ELISA was higher than that detected by rapid assay showing that fourth generation ELISA is a more sensitive test than rapid assay as well as a better diagnostic modality to opt for when coming to early detection in HIV.