Abstract
<jats:p>Women engaged in informal cross-border trade in Southern Africa experience frequent mobility, economic pressure, and exposure to new social environments that may increase vulnerability to risky sexual behaviour and HIV. Limited evidence exists on how pre-migratory, migratory, and post-migratory factors interact to shape sexual risk among this population. This study examined the prevalence and determinants of risky sexual behaviour among women informal cross-border traders at COMESA Market in Lusaka, Zambia. A cross-sectional survey was conducted with 499 women informal cross-border traders. A composite risk score was used to classify respondents as "low risk" or "high risk" for sexual behaviour. Descriptive statistics, chi-square tests, and multivariate binary logistic regression were used to investigate associations between selected covariates and risky sexual behaviour, guided by migration and vulnerability theory. The majority (67.7%) of respondents were classified as high-risk. In multivariate analysis, women who used personal savings for start-up capital were 73% less likely to be high-risk compared to those relying on nuclear family capital (aOR = 0.27, 95% CI: 0.10-0.73). Women with 5-9 years of trading experience also had lower odds (aOR = 0.21, 95% CI: 0.29-0.96). Conversely, using Katima Mulilo border increased the odds 15-fold (aOR = 14.59, 95% CI: 1.26-169.50). Not feeling disconnected while away (aOR = 3.39, 95% CI: 1.03-11.11) and sharing accommodation with one roommate (aOR = 4.42, 95% CI: 1.10-17.84) were also significant predictors of high-risk behaviour. This study demonstrates that risk among women informal cross-border traders is produced across the migration continuum by economic dependence, specific transit routes, and destination living conditions. Interventions should therefore prioritise financial independence, targeted health and protection services at high-risk borders, and safe accommodation with peer-led HIV prevention to reduce vulnerability among mobile women traders.</jats:p>