Seroprevalence of HSV-1 and 2 among sex workers attending a sexually transmitted infection clinic in Singapore

We studied the seroprevalence of herpes simplex virus (HSV)-1 and 2 in sex workers attending a sexually transmitted infection clinic in Singapore and examined their knowledge and attitudes towards HSV infection. A total of 300 participants were recruited. Questionnaires were administered and blood was taken and analysed, using the HerpeSelect 1 and 2 Elisa IgG assays (type-specific serological test). HSV-1 serology was positive in 230 (76.7%), negative in 67 (22.3%) sex workers and indeterminate in three (1.0%) sex workers. HSV-2 serology was positive in 237 (79.0%) and negative in 63 (21.0%) sex workers. On univariate analysis, there was significant association between HSV-2 seropositivity and increasing age, nationality (locals) (P < 0.001) and marital status (P < 0.01). Adjusting for age, marital status and condom use, HSV-2 prevalence increased significantly with duration of years of practice of sex work. Most of the respondents (86.0%) were aware that HSV could be spread through sex without a condom and about two-thirds of them were aware that HSV could be spread in the absence of symptoms. In conclusion, HSV-2 is a common infection among sex workers in Singapore with the risk increasing with years of practice.