Miranda AE et al. - Overall, 6.1% had at least one positive serological marker for any of the tested infections. A majority was sexually active, of whom 12.1% reported a previously diagnosed sexually transmitted infection (STI) and 1.4% a history of commercial sex work. Variables independently associated with any positive serological test included: older age, low monthly income, previously diagnosed STI, >=1 sexual partner, and any illicit drug use.