The false-positive and false-negative predictive value of HIV antibody test in the Chinese population.
OBJECTIVE
To analyse the relationship between the false-positive/false-negative predictive value (FPPV/FNPV) of the HIV-antibody (HIV-Ab) test and prevalence in different Chinese population groups.


METHODS
HIV prevalence among different population groups was obtained by a screening survey of blood donors and the national HIV/AIDS surveillance programme in China. Given the sensitivity and specificity of a test kit and the prevalence of HIV infection, the estimated values of FPPV/FNPV were calculated using Bayes' formula. The actual value of FPPV of blood donors was obtained by screening 1,195,286 blood donors.


RESULTS
This study indicates that the FPPV of HIV-Ab enzyme-linked immunosorbent assay (ELISA) assays varies widely in different Chinese populations: about 99.5% in the blood donor population, but only 3.2% in the injecting-drug users in high-risk areas. In 1,195,286 sera specimens from the blood donors, 2439 specimens were HIV-Ab positive by third ELISA, and 11 HIV cases were confirmed by Western blot. The HIV prevalence of the blood donor population in this survey was 0.0009% (11/1,195,286), but the HIV-Ab positive rate of third ELISA is 0.2% (2439/1,195,286) and 222 times higher than the prevalence.


CONCLUSIONS
Evaluation of HIV prevalence through the HIV-Ab positive rate by third ELISA will significantly overestimate the true prevalence in a low-prevalence population. Individual HIV-infection status should be taken into consideration when analysing the results of HIV-Ab tests in a population with low infection.
Liu
Pei
P
Department of Epidemiology and Biostatistics, School of Public Health, Southeast University, Nanjing 210009, Jiangsu, China.
Shi
Zhixu
Z
Wang
Cannan
C
Yang
Haitao
H
Li
Lei
L
Dai
Yudong
Y
Liu
Yuanbao
Y
Sun
Jinfang
J
Pu
Yuepu
Y
D044466:Asian People / Q000706:statistics & numerical data*; D001782:Blood Donors; D015153:Blotting, Western; D002681:China / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015483:HIV Antibodies / Q000097:blood*; D006679:HIV Seropositivity / Q000097:blood* / Q000208:ethnology; D015528:HIV Seroprevalence; D015497:HIV-1 / Q000276:immunology; D015498:HIV-2 / Q000276:immunology; D006801:Humans; D011247:Pregnancy; D015995:Prevalence
D015483:HIV Antibodies