Introduction Due to cultural characteristics, there are some potential risks for HIV/STI transmission including early sexual debut and multiple sex partners among Dao ethnic people. This study aims to measure HIV/STI prevalence and risk behaviour among this ethnic minority in Viet Nam.

Methods Household survey was carried out to recruit 807 and 802 Dao people in 2006 and 2012. A two-stage cluster sampling design was used. The households were chosen randomly based on the list of local authority. All women and men aged 15–49 was eligible to be selected into the survey. Participants were asked to be interviewed and provide 3 ml bloods for HIV/STI testing.

Results Syphilis prevalence was 3.4% and 5.6% in 2006 and 2012, respectively. HIV prevalence was 0.0% in both rounds. Mean age of sexual debut was 17.5 (SD: 2.3 years old) and 17 years old (SD: 1.7 years old) in 2006 and 2012, respectively. Correct knowledge on HIV prevention was 18.7% and 50.2% in 2006 and 2012, respectively. Having multiple sex partners in the last 12 months was 5.8%, 8.6% for men and 3.0% for women, and 30.1%, 38.5% for men and 22.2% for women, in 2006 and 2012 respectively. Always using condom with any sexual partners in the last 12 months was 3.5% and 5.1% in 2006 and 2012, respectively. Using drug was 1.4% in both rounds. HIV testing and knowing the result were 1.1% and 31.8% in 2006 and 2012, respectively. Among aged 15–24 groups, the correct knowledge on HIV prevention was increased from 21.0% (2006) to 52.9% (2012); always using condom with any sexual partners in the last 12 months was increased from 5.9% (2006) to 12.0% (2012) and syphilis prevalence was decreased from 3.1% (2006) to 1.6% (2012).

Conclusion High syphilis prevalence combined with high sexual risk behaviour such as multiple sex partners and low consistent condom use suggests high potential risk for HIV/STI transmission among Dao ethnic people. In addition, low-level knowledge on HIV/AIDS prevention and STI treatment warrants extra attention. HIV prevention effort needs to ensure reaching this remote and vulnerable ethnicity with focus on young in Viet Nam.

Disclosure of interest None.