The HIV epidemic in Zambia: socio-demographic prevalence patterns and indications of trends among childbearing women

Abstract

Objective: To examine socio-demographic HIV prevalence patterns and trends among childbearing women in Zambia.

Design: Repeated cross-sectional surveys.

Methods: Personal interviews and unlinked anonymous testing of blood samples of women attending antenatal care in selected areas.

Results: The 1994 data includes information from 27 areas and a total of 11,517 women. The HIV prevalence among urban residents appeared with moderate variation at a very high level (range 25-32%, comparing provinces). The geographical variation was more prominent in rural populations (range 8-16%) and was approximately half the prevalence level of the urban populations. With the exception of the 15-19 years age-group, HIV infection was found to rise sharply with increasing educational attainment (odds ratio, 3.1; confidence interval, 2.6-3.8) when contrasting extreme educational levels. Although the assessment of trends is somewhat restricted, the available information indicates stable prevalence levels in most populations over the last 2-4 years.

Conclusions: The data showed extremely high HIV prevalence levels among childbearing women. Longer time-intervals between surveys are needed, however, in order to verify the stability in prevalence identified by this study. The tendency to changing differentials by social status is suggested as a possible sign of an ongoing process of significant behavioural change.

PIP: A series of cross-sectional surveys conducted in Zambia revealed extremely high HIV prevalence among childbearing women. The analysis was based on data derived from an HIV sentinel surveillance system established among childbearing-age women in Zambia in 1990 and expanded in 1994 to improve geographic coverage and obtain data on socio-demographic characteristics. In 1994, when complete data on HIV status was obtained on 11,517 women from 27 areas, overall HIV prevalence was 19.8%. This rate ranged from 22% to 35% in Lusaka and provincial headquarters, from 25% to 32% in urban areas, and from 8% to 16% in rural areas. In both urban and rural areas, HIV prevalence was highest in the 25-29 year age group (34% and 17%, respectively). With the exception of the 15-19 year group, seroprevalence also rose significantly with increasing educational attainment; the odds ratio was 3.13 for the most educated compared to the least educated women. The lack of HIV prevalence socioeconomic differentials among 15-19 year olds, who became sexually active at a time when information about AIDS prevention was available, may be indicative of a process of behavioral change. Only 1 area (Kalabo) showed a trend of increase in the past 2-3 years; in other areas, HIV infection rates appear to have stabilized.