The comparison of the performance between third generation ELISA and fourth generation ELISA on acute and early HIV infection

Abstract

Objective To evaluate the performance of the third generation ELISA and the fourth generation ELISA for HIV-1 diagnosis assays on acute and early HIV-1 infected samples. Methods Sixty-seven acute/early HIV-1 infected samples were collected from the follow-up gays with seroconversion in Shen Yang city and from clinical patients in the First Affiliated Hospital of China Medical University with incomplete HIV-1 specific bands in western blot between 2008 and 2010.Third generation ELISA, fourth generation ELISA, western blot and HIV-1 viral load detecting were used for detecting these samples.The sensitivity, consistency were compared between third generation ELISA and fourth generation ELISA to detect the seroconversion samples and the window periods were abserved.Chi square test was used for statistical analysis. Results In the 67 acute/early HIV-1 infected samples, 56 were HIV positive and 11 were HIV negative by the third generation ELISA.The sensitivity of the third generation ELISA was 83.6% (95%CI:72.5%-91.5%); 63 were HIV positive，1 was at gray zone and 3 were HIV negative by the fourth generation ELISA.The sensitivity of the fourth generation ELISA was 94.0% (95%CI:85.4%-98.3%),higher than the third generation ELISA（χ2=16.1，P<0.01）.The consistency of the third generation ELISA and the fourth generation ELISA was 86.6%(95%CI：76.0%-93.7%).The earliest third generation ELISA positive sample was the sample collected 16 days after HIV infection and the earliest fourth generation ELISA positive sample was the sample collected 9 days after HIV infection.There was significantly different on the window periods between the third generation ELISA and the fourth generation ELISA. Conclusion The fourth generation ELISA had a higher sensitivity and shorter window period on acute/early HIV infected samples than the third generation ELISA, which is more suitable for the HIV early infection screening on high risk populations. （Chin J Lab Med，2012,35：538-543） Key words: HIV infections; HIV-1; Enzyme-linked immunosorbent assay