Analysis on confirmation results of HIV antibody test in Liaoyang city,2011-2013

ObjectiveTo examine the status of human immunodeficiency virus(HIV)antibody screening and confirmation test in Liaoyang city and to provide evidences for improving HIV infection detection in the city.MethodsWestern blot(WB)assay was adopted in the confirmation test according the requirement of National Technical Manual for HIV testing;chi-square test was used in data analysis.ResultsOf the 128 HIV antibody positive specimens during the period of 2011-2013 in the city,85(66.41%)were positive,28(21.88%)were negative,and 15(11.72%)were indeterminate based on the results of WB confirmation assay and there was a statistically significant difference in the distribution of standard deviation/cut off value(S/CO)among the screening results with the three types of confirmation outcome(χ²=111.794,P<0.05);for the specimens with the S/CO value of>6 in the screening test,the WB confirmation positive rate was 95.3% (81/85)and 49.4% (42/85)of the specimens showed full pattern in WB band type.ConclusionThere are false positive results in HIV antibody screening,even for the specimens with the S/CO value of>6 and confirmation test is needed.