HIV serosurveillance in Papua New Guinea.

To determine human immunodeficiency virus-1 (HIV-1) prevalence in low- and high-risk populations in Papua New Guinea (PNG), anonymous unlinked serosurveillance was conducted in government-administered antenatal and sexually transmitted disease (STD) clinics at six sites beginning in June 1989. Although 3 of 1233 samples were HIV positive in a pilot study, none of 7948 samples was HIV positive during the first full year of serosurveillance (June 1989--May 1990). HIV-infected people are also identified in PNG through clinical diagnostic testing. Although underreporting is probably substantial, 45 HIV-infected people had been identified in PNG (population 3.6 million) through diagnostic testing between 1987 and the end of the first serosurveillance year (May 1990). In view of the steadily emerging clinical problem of acquired immune deficiency syndrome (AIDS) in PNG, the negative results of serosurveillance required explanation. Three possibilities are proposed: 1) the sample size chosen could fail to detect a case 5% (or more) of the time under the likely conditions of this survey; 2) the populations chosen for surveillance may not, yet, be those in which HIV is circulating at this early stage of the epidemic in PNG; and 3) laboratory error could account for some false negative results. The first two of these, alone or in combination, are most likely. Limited surveillance continued in PNG in 1991 and 1992. By June of 1992, 5 of an additional 6035 serosurveillance samples had tested positive. All 5 were among 2000 samples from a single site, the Port Moresby STD Clinic.(ABSTRACT TRUNCATED AT 250 WORDS)