SENTINEL SURVEILLANCE AND CROSS-SECTIONAL SURVEY ON HIV-INFECTION PREVALENCE - A COMPARATIVE-STUDY

Despite widespread use of sentinel surveillance systems in monitoring the magnitude of HIV-1 infection in populations, little is known of ho w the trends they produce compare with those of the larger populations which they pupport to represent. The objective of this study, therefo re, was to assess how useful sentinel surveillance data on HIV-1 infec tion might he in estimating the magnitude of HIV-1 infection in the ge neral population. To achieve this, results from a population based stu dy on HIV-1 infection in Bukoba town were compared with those from ant enatal mothers and blood donors, all from the same town. The studies w ere, done during the period of 1987-90. The overall HIV-1 prevalence w as highest in the general population sample at 24.2 % (95% CI 20.6-27. 8) followed by that in antenatal mothers at 22.4% (95% CI 20.6-25.2) a nd lowest in blood donors at 11.9 % (95% CI 9.1-15.3). Seroprevalence among antenatal clinic attenders was significantly lower than that of females from the general population sample (p=0.016). Prevalence among female blood donors did pot differ significantly from that of females from the general population sample (p=0.06). Blood donor males had a lower HIV-1 seroprevalence when compared to that from the general popu lation males (p=0.038). The age group 25-34 years had the highest prev alence of HIV-1 infection in all the three populations indicating that this group is at the highest risk of HIV infection and that the three populations show a similar trend of age specific prevalence. From the se findings, it is noted that female blood donors as a sentinel popula tion represents more closely estimates of HIV-1 seroprevalence of fema les in the general population than antenatal clinic attenders or male blood donors. Further studies are proposed in different settings in or der to come up with guidelines on the methodology of using sentinel su rveillance populations in monitoring HIV-1 infection.