Role of widows in the heterosexual transmission of HIV in Manicaland, Zimbabwe, 1998-2003

Abstract

Background: AIDS is the main driver of young widowhood in southern Africa.

Methods: The demographic characteristics of widows, their reported risk behaviours and the prevalence of HIV were examined by analysing a longitudinal population-based cohort of men and women aged 15-54 years in Manicaland, eastern Zimbabwe. The results from statistical analyses were used to construct a mathematical simulation model with the aim of estimating the contribution of widow behaviour to heterosexual HIV transmission.

Results: 413 (11.4%) sexually experienced women and 31 (1.2%) sexually experienced men were reported to be widowed at the time of follow-up. The prevalence of HIV was exceptionally high among both widows (61%) and widowers (male widows) (54%). Widows were more likely to have high rates of partner change and engage in a pattern of transactional sex than married women. Widowers took partners who were a median of 10 years younger than themselves. Mathematical model simulations of different scenarios of sexual behaviour of widows suggested that the sexual activity of widow(er)s may underlie 8-17% of new HIV infections over a 20-year period.

Conclusions: This combined statistical analysis and model simulation suggest that widowhood plays an important role in the transmission of HIV in this rural Zimbabwean population. High-risk partnerships may be formed when widowed men and women reconnect to the sexual network.

Figure 1

Prevalence of widowhood and remarriage patterns by age and sex in Manicaland, Zimbabwe, 2001–3. (A) Men: prevalence of widowers at baseline and follow-up. (B) Women: prevalence of widows at baseline and follow-up. (C) Men: prevalence of remarried and unmarried widowers at follow-up. (D) Women: prevalence of remarried and unmarried widows at follow-up.

Figure 2

Total number of partnerships in 3-year follow-up period based on marital status at baseline: 0 (light grey), 1 (dark grey), >1 (black).

Figure 3

Kaplan-Meier survival plot of remarriage after widowhood (n = 99 men; 644 women).

Figure 4

Model prediction. Percentage of cases averted over 20 years after cessation in sexual behaviour of male, female and all widows. Four scenarios of the pre-intervention mixing and sexual activity patterns of widows (W) and non-widows (NW) are presented: (1) Widows form more sexual partners than non-widows, the age difference between partners is higher for widows than non-widows, and widows form most of their partnerships with non-widows (black bars). (2) As for (1), but with the same numbers of sexual partners (dark grey bars). (3) As for (2), but age difference between partners is the same (light grey bars). (4) As for (3), but widows preferentially form partnerships with other widows (white bars).