Objectives: A limited number of studies in Asia have investigated HIV transmission in the general population in order to better guide preventive efforts. We examine HIV prevalence patterns in men and women aged 15-49 years in Cambodia.

Methods: The first national population-based survey was conducted in 2005, including HIV-related questionnaires and HIV test. Data were analysed separately for men and women. Logistic regression analysis, adjusted by age, was used to determine factors associated with HIV. To estimate the HIV prevalence, it was standardized by age, sex and place of residence.

Results: Among 6514 men and 8188 women, HIV prevalence was 0.61% [95% confidence interval (CI) 0.2-1.8] and 0.62% (95% CI 0.3-2.1), respectively. The prevalence in urban areas was approximately three times higher than in rural settings. The likelihood among women of being HIV positive increased with increasing age differentials between spouses. HIV among men increased with household wealth (odds ratio 5.7; 95% CI 2.0-16.4) and education (odds ratio 3.7; 95% CI 0.8-17.8). About 10% of men reported multiple partners, a behaviour strongly associated with HIV (odds ratio 4.0; 95% CI 1.3-12.5).

Conclusion: This study revealed HIV prevalence to be relatively low in the general population and substantially below previous estimates. Multiple observations were consistent with the hypothesis that the bulk of infections among men are related to sex work and most women are infected in marriage. Intervention should be focused on reducing the transmission among spouses and empower women with better access to information, education and care while sustaining preventive efforts related to sex work.