Is antenatal syphilis screening still cost effective in sub-Saharan Africa.

OBJECTIVES: To estimate the cost effectiveness of on-site antenatal syphilis screening and treatment in Mwanza, Tanzania. To compare this intervention with other antenatal and child health interventions, specifically the prevention of mother to child transmission of HIV (PMTCT). METHODS: The economic costs of adding the intervention to routine antenatal care were assessed. Cost effectiveness (CE) ratios of the intervention were obtained for low birth weight (LBW) live births and stillbirths averted and cost per DALY saved. Cost per DALY saved was also estimated for previous CE studies of syphilis screening. The CE of the intervention at different syphilis prevalence rates was modelled. RESULTS: The economic cost of the intervention is $1.44 per woman screened, $20 per woman treated, and $187 per adverse birth outcome averted. The cost per DALY saved is $110 with LBW as the only adverse outcome. When including stillbirth, this estimate improves 10-fold to $10.56 per DALY saved. The cost per DALY saved from all syphilis screening studies ranged from $3.97 to $18.73. CONCLUSIONS: Syphilis screening is shown to be at least as cost effective as PMTCT and more cost effective than many widely implemented interventions. There is urgent need for scaling up syphilis screening and treatment in high prevalence areas. The CE of screening interventions is highly dependent on disease prevalence. In combination, PMTCT and syphilis screening and treatment interventions may achieve economies of scope and thus improved efficiency.

Sentinel surveillance for HIV-1 among pregnant women in a developing country: 3 years' experience and comparison with a population serosurvey.

OBJECTIVES: To establish unlinked, anonymous sentinel surveillance for HIV-1 among pregnant women attending an antenatal clinic, to determine age-specific seroprevalences, to monitor trends and to compare seroprevalence with that detected by a population serosurvey. To establish the sustainability and costs of surveillance. DESIGN: Sentinel surveillance for HIV through serial collection of unlinked, anonymous seroprevalence data from antenatal care; comparison of sentinel data with those from a population serosurvey; financial and general audit of the sentinel surveillance. SETTING: A community antenatal clinic in a large urban centre, Mwanza Municipality, Tanzania, eastern Africa, between October 1988 and September 1991. PATIENTS: Pregnant women attending for antenatal care. MAIN OUTCOME MEASURE: Age-specific HIV-1 seroprevalences, trends over time, difference from age-specific population seroprevalences, sustainability and costs. RESULTS: Overall HIV-1 seroprevalence was 11.5% (95% confidence interval, 10.5-12.4); differences in age-specific prevalences were not significant. There was no clear evidence of change in seroprevalence over the study period in any age group, although there was some indication of a rise in some age groups in 1988-1989. Sentinel surveillance among pregnant women may have significantly underestimated population HIV-1 seroprevalence for women under the age of 35 years. HIV-1 surveillance proved feasible and sustainable. Additional recurrent costs were US$1.7 per specimen for unlinked anonymous testing and US$0.57 per woman for syphilis screening. CONCLUSIONS: HIV-1 seroprevalence did not change significantly over 3 years, probably implying a substantial incidence of HIV-1 infection. In this setting seroprevalence in pregnant women may have underestimated population seroprevalence in women aged under 35 years. With modest inputs and good organization unlinked anonymous HIV-1 sentinel surveillance of pregnant women can be introduced and sustained in an African setting. This may usefully be carried out in conjunction with syphilis screening.

PIP: Between October 1989 and September 1991, health workers took blood samples from pregnant women attending Makongoro Clinic in Mwanza, Tanzania, to determine age-specific HIV-1 seroprevalence in pregnant women, trends over 3 years, and the feasibility, sustainability, and costs of HIV monitoring and to compare age-specific seroprevalences in pregnant women with those of all women. Overall, HIV prevalence among pregnant women stood at 11.5%. Even though the younger and older age groups had lower seroprevalence than the other age groups (10% for those under 20 years old, 11% for 30-34 year olds, and 8.3% for = or 35 year olds vs. 12.8% for 25-29 year olds and 12.3% for 20-24 year olds), the differences were not significant. HIV seroprevalence appeared to increase in 1988-89 in most age groups, but no significant evidence of a linear trend occurred during the study period for any age group. This absence of significant change in HIV seroprevalence over 3 years likely indicated a considerable HIV incidence. The population serosurvey revealed an HIV seroprevalence of 15.1% among the general adult female population, suggesting that the sentinel surveillance among pregnant women could have greatly underestimated population HIV seroprevalence for women under 35 years old (p = .02). Sentinel surveillance improved the clinic's ability to detect anemia and reintroduced syphilis screening. Unlinked anonymous testing resulted in additional recurrent costs of S$1.7/specimen. Syphilis screening added recurrent costs of US$0.57/woman. These findings indicated that health workers in Africa can successfully introduce and maintain anonymous HIV-1 sentinel surveillance of pregnant women and this can be accomplished with concurrent syphilis screening.