Abstracto

Development of sensitive, specific, point of care enzyme-linked immunosorbent assay combined with DBS and hand-held ELISA reader for the rapid detection of hepatitis C virus in resource-limited settings

Soumendra Nath Maity, Prudhvi Chand Mallepaddi, Nagababu Pyadala, Sujaya Raghavendra, Sai Sailesh Kumar, Vijayaraghavan R, Rathnagiri Polavarapu

Background: Hepatitis C virus cause liver infection which can lead to liver cirrhosis and hepatocellular carcinoma. Identification of hepatitis C virus infection initially depends on the antibody screening test.

Aim and Objectives: We developed highly specific and sensitive recombinant protein-based HCV ELISA and combined the assay with Dried Blood Spot (DBS) assay and hand-held ELISA reader to establish its use in limited resource areas as well as in field level.

Materials and Methods: A total of 610 specimens were collected for assay validation purpose. To check the proficiency of our diagnostic strategy, we compared our test results with standard HCV chemiluminescence enzyme immune assay. The Institutional Ethical Committee approved this study (IEC). NCSS 11 statistical software analysed all the data. The correlation-regression was done to compare the assay. The level of significance of this study was p<0.05.

Results: Among 60 known reactive specimens, 59 showed reactive by HCV ELISA and chemiluminescence enzyme assay. Therefore sensitivity for both the assay recorded 98.33%. Out of 150 known non-reactive samples, both the method showed the nonreactive result. Thus specificity calculated 100%. While HCV ELISA tested with DBS, we found no significant difference in specificity and sensitivity of the assay (r2=0.9940). ELISA optical density value obtained by Hand-held ELISA reader showed better performance as compared to Tulip ELISA plate reader (r2=0.9921). While performed field study, out of 400 specimens, 6 showed reactive by both the methods. Therefore specificity and sensitivity was 100% for in-house HCV ELISA as compared to chemiluminescence assay. In this case, also we found a good performance of DBS assay (r2=0.9476). There was a good correlation between O.D. obtained by hand-held ELISA reader and Tulip ELISA plate reader (r2=0.9923).

Conclusion: According to our study report, in-house HCV ELISA is highly specific and sensitive method. Addition of DBS assay and hand-held ELISA reader makes it possible to run the assay in limited resource settings as well as in field level or outside the standard laboratory setup. This unique HCV diagnostic strategy can reduce the global burden of HCV infection.