Analysis of false positive-reaction in one case of HIV antibody confirmatory testing

Objective To explore the technical problems of the HIV-Ab test including screening and confirmatory testing following up a HIV-Ab positive case. Methods Antibody screening and confirmatory tests were carried out on the subject at 3,6,12 months. Results Of the initiate testing,negative-reaction occurred with PA(SFD HIV1/2) while positive reaction occurred with vironostika Ab-EIA.Thus the HIV-1 antibody was positive based on confirmatory test which showed the type of WB blet was gp120p24.Of the comparative testing,positive reaction also occurred with vironostika Ag/Ab-EIA while negative-reaction with kinghawk-EIA and GBI-EIA.In addition,Dainabot Determine(HIV1/2) met with a weak positive-recation and the virus-load was not detected.Of the 3 testings of follow-up,the screening testing met the same outcome of the initiate testing,the types of WB blet were gp120p24,p24 and p24p55 respectively,and virus-load of the last sample was not detected.Therefore the result of HIV-1 antibody negative was summed out.Of the total 4 tests,screening testing makes dfference among not the series but the brand of reagent,while confirmatory testing makes dfference among the series. Conclusion There is some difference among the series of reagent in the confirmatory testing,so that the comparative testing and re-testing should be carried out as the sample with weak or odd postive-reaction is concerned.Epidemiology investigation should be carried out when the result turned to be critical;uncertainty of HIV-Ab happened when one env belt with p24 appeared at the same time by WB confirmatory test,and follow up the subject.