Emil Asamoah-Odei | PubMed Health

PubMed2004

Second-generation HIV surveillance: better data for decision-making.

This paper seeks to outline the key elements of the expanded surveillance efforts recommended by the second-generation HIV surveillance approach. Second-generation systems focus on improving and expanding existing surveillance methods and combine them in ways that have the greatest explanatory power. The main elements of this approach include: considering biological surveillance - HIV, AIDS, sexually transmitted infections (STIs) - and behavioural surveillance as integral components, targeting surveillance efforts at segments of the population where most new infections are concentrated - which might differ depending on the stage and type of the epidemic - and providing the rationale for the optimal use of data generated for monitoring the HIV epidemic and evaluating national AIDS control programmes. The paper emphasizes improvements in existing surveillance methodologies and discusses in detail crucial issues such as the validity of HIV prevalence data measured in pregnant women and linking HIV surveillance and behavioural data collection. In addition, a strategic partnership between second-generation surveillance and AIDS programme evaluation is proposed that stresses the complementary roles of these data collection activities in determining the effectiveness of prevention and care programmes and explaining the epidemiological trend data collected by sentinel serosurveillance systems. In conclusion, second-generation HIV surveillance systems provide a comprehensive, cost-effective and appropriate response to the information needs of AIDS control programmes. The implementation of such systems, including a better use of the data generated by the system, will ensure that national programmes are in the best possible position to respond to the challenges of the epidemic.

Behavioral Risk Factor Surveillance System↗

PubMedDate not supplied

HIV prevalence and trends in sub-Saharan Africa: no decline and large subregional differences.

BACKGROUND: Expansion of HIV surveillance systems in sub-Saharan Africa is leading to downward adjustments to the size of the AIDS epidemic. However, only analysis of surveillance data from the same populations over time can provide insight into trends of HIV prevalence. We have used data from the same antenatal clinics to document recent empirical trends. METHODS: We collated data from antenatal clinics on HIV prevalence between 1997 and 2003. Data were obtained from 140?000 pregnant women attending more than 300 antenatal clinics in 22 countries in sub-Saharan Africa. Additionally, long-term trend data are available for 57 urban areas and provinces. FINDINGS: Median HIV prevalence in 148 antenatal clinic sites in southern Africa increased from 21.3% (IQR 11.5-28.2%) in 1997/98 to 23.8% (15.6-29.2%) in 2002. At more than half the sites (58%) an increase of at least one-tenth was noted, but at a fifth of sites, prevalence dropped by at least one-tenth. In eastern Africa, median HIV prevalence decreased from 12.9% (7.0-16.9%) in 1997/98 to 8.5% (5.3-13.0%) in 2002, with prevalence rising in four (7%) sites, but falling at 25 (43%) sites. In west Africa, median HIV prevalence was 3.5% (2.2-5.9%) and 3.2% (2.3-6.1%) for 1997/98 and 2002, respectively, with reductions and increases in prevalence being noted in equal proportions. The long-term trends in urban areas in sub-Saharan Africa show a similar pattern, with increasing evidence of stabilisation during the past 2-3 years compared with the previous decade. INTERPRETATION: Evidence from surveillance of mostly urban antenatal clinic attendees indicates that the growth in the AIDS epidemic in sub-Saharan Africa has levelled off since the late 1990s but only eastern Africa shows a decline in HIV prevalence. Very large differences persist between subregions. Workers planning a response to the AIDS epidemic must take more careful consideration of these variations to allow locally appropriate responses to the epidemic.

Adolescent↗