BMC Public Health 2006, 6:109 http://www.biomedcentral.com/1471-2458/6/109 3.5 4 3 2.5 ) % ( e c le2 n a v e r p V 1.5 I H 1 0.5 0 Remote Rural 15-19 20-24 Age groups (years) 25-29 30+ RFAuiggerua–lrMespa1encyiafircaHanIVd pSrinegviadlaenrceegiaomnso,nTgaannztaenniaa,ta2l0a0t3te–n2d0e0e4s in Age – specific HIV prevalence among antenatal attendees in Rural Manyara and Singida regions, Tanzania, 2003–2004. Factors associated with HIV infection on univariate analysis On univariate analysis, HIV infection was significantly associated with the number of lifetime husbands/sexual partners; OR 4.8 (95%CI: 1.75–13.17) and polygynous relationships (Fisher's exact test, p < 0.01) that character- ise the majority of relationships 99% (1289/1296). Women who reported more than one lifetime sexual part- ner, had an HIV prevalence of 7.7% and had 4.8 times likelihood of being HIV infected, compared to those reporting one partner only. Women who had been using contraceptives of any kind, were more likely to be HIV infected; OR 2.8 (95%CI: 1.25–6.48) compared to non- users (Table 2). HIV infection was highly associated with first pregnancies at ages below 18 years compared to first pregnancies at ages above 18 years. A history of either gen- ital sore or foul smelling genital discharge increased the odds of HIV infection by 4.6; OR 4.6 (95%CI: 2.06– 10.39). Women, who had ever received voluntary coun- selling and testing, were twice more likely to be HIV infected; OR 2.6 (95%CI: 1.20–5.72). Single, divorced or separated women had 1.9 odds of being HIV infected but not significantly; OR 1.9 (95%CI: 0.65–5.72). Women who had ever used a condom were more likely to be HIV infected, OR 3.7 (95%CI: 1.25–11.18) compared to those who have never used condoms. Factors associated with HIV infection on multivariate analysis HIV remained significantly associated with more than one of lifetime sexual partners OR 4.3 (95%CI: 1.42–12.77) and history of genital discharge or sore, OR 6.8 (95%CI: 2.78–16.66). In addition, women who had their first pregnancy at 18 years or older were less likely to be HIV infected compared to those being pregnant for the first time at less than 18 years OR 0.3 (95%CI: 0.13–0.89). Discussion This study provides a comprehensive sentinel surveillance of HIV in these very remote rural regions of Manyara and Singida in Northern Tanzania. The HIV prevalence for the area was 2.0% with a rural: remote rural ratio of two. Compared to other rural areas in Tanzania, this preva- lence is relatively low. For example in Mbeya region, the ANC-based prevalence in 2002 was 13.5% and 23.3% in Isoko and Itete, both being rural areas respectively, whereas in rural Moshi it was 16.6% [22]. However, there were signs indicating that the HIV incidence might be increasing in the area. First, epidemics on the increase will tend to show a negative association between age and infection. A second indication was the findings from hos- pital-based screening of HIV infection done in the main antenatal clinics in the same region in 1995/96 and 1999. These showed a prevalence of 0.3% [(95%CI: 0.04–1.1), (n = 2/733)] and 0.4% [95%CI: 0.07–1.7), (n = 2/467)], respectively [23]. A reflection of the relatively general low exposure to sources of infection rather than absence of risks factors that are also evident elsewhere [24]. This area had limited accessibility in the last decade, due to poor infrastructure, hence less traffic and reduced mobility [23]. This might have been among the factors that limited the sources and spread of infection. However, the situa- tion is now changing with improvements in roads, increase in trade and mobility, which in turn may escalate the spread of HIV infection in these communities [25]. It is likely that the rural area with a relatively higher HIV prevalence presents marked current changes compared to the remote area. This study included all pregnant women from all divi- sions that fall within the geographical boundaries of the catchment area. Though documented that in Tanzania, that 98% of pregnant women receive antenatal care [26], some areas lacked established clinics. In order to address this void, planned monthly outreach reproductive and child health (RCH) clinics from HLH and government RCH clinics take place throughout the year. Thus, biases due to non- attendance are likely to be minimal, owing to the placement and coverage of clinics, and absence of pri- vate clinics in the area. However, as these clinics are also entry points for PMTCT, VCT is mandatory in order to be tested, and this introduces potential selection bias since it requires consent. This might over-estimate the HIV preva- lence among pregnant women since pregnant women per- ceiving themselves to be HIV infected from neighbouring areas outside the catchment area, might seek health serv- ices from this locality to benefit from the PMTCT interven- tion. Under-estimation is also a possibility since such Page 5 of 9 (page number not for citation purposes)