Factors associated with sexually transmitted diseases among prostitutes in Singapore.

From June to December 1990, 806 prostitutes registered with the STD programme in Singapore for regular screening for sexually transmitted diseases (STD) were investigated for factors associated with STD incidence in the preceding year. The majority were foreigners (92.7% Malaysians and 3.1% Thais). Anal sex (0.4%) and intravenous drug use (0.9%) were rare. The overall STD incidence rate was 47.7 per 100. None was human immunodeficiency virus (HIV) positive. The crude and age-adjusted risk of STD was found to increase significantly with client load. An inverse relationship between condom use and STD risk was also observed. Mean condom use among clients was reported as 56.1% for spontaneous use and estimated as 75.4% following negotiation for condom use by prostitutes. Although the prostitutes negotiated for condom use with majority of the clients (85.5%) who did not use condoms spontaneously, they were successful with only about half of them (54.4%). Health education should be targeted at clients on the protective effects of condom use and at the prostitutes on skills in negotiating condom use.