Uptake of provider-initiated HIV and syphilis testing among heterosexual STD clinic patients in Guangdong, China: results from a cross-sectional study.

The low-level of HIV and syphilis testing uptake, alongside with the high-level of engagement in risky sexual behaviours among heterosexual STD clinic patients, warranted a more targeted and intensive behavioural interventions to promote HIV and syphilis testing in this population.