Background:  Since the introduction of HAART, an increase in sexually transmitted infections (STI) has been observed in men who have sex with men (MSM) who are aware of their HIV⁺ status. Many of these STI may be asymptomatic. The question is whether regular STI screening should be considered for all HIV-infected MSM. Therefore, we studied the prevalence and factors associated with asymptomatic STI in a representative group of HIV⁺ MSM in the Netherlands.

Methods:  MSM visiting the HIV outpatient clinic of 2 academic hospitals were screened for STI during a routine visit. Patients spontaneously reporting symptoms compatible with STI were excluded. C. trachomatis (CT) and N. gonorrhoeae (NG) were tested by PCR on oral swabs, anal self swabs. and urine samples. Antibodies against hepatitis B virus (HBV) and hepatitis C virus (HCV) were measured and patients were screened for syphilis by conventional treponemal antigen and antibody tests. MSM completed a questionnaire about sexual behavior in the previous 6 months. Using logistic regression, we assessed associations between sexual behavior and the presence of any of the following STI: CT, NG, or syphilis.

Results:  Between October 2007 and June 2008, 659 MSM (median age 45.4 years, range 19.8 and 79.3) were included. CT, NG or a new syphilis infection was found in 14.4% of patients. Other results are shown in Table 1. Almost 87% of patients with CT or NG diagnoses had anal infections. One new HBV and 3 new HCV infections were identified. In multivariate analysis, having had more than 2 steady or more than 2 casual partners (OR = 2.5, 95%CI 1.4 to 4.5), unprotected anal sex or other high-risk sexual techniques (fisting, use of sexual toys, or rimming) (OR = 2.3, 95%CI 1.2 to 4.4), and enema use (OR = 2.3, 95%CI 1.3 to 4.2), all in the last 6 months, were associated with presence of any of the following: CT, NG, or syphilis.

Conclusions: More than 10% of HIV⁺ MSM attending our HIV outpatient clinics in the Netherlands, had one or more asymptomatic STI, mostly CT and syphilis. Having had more than 2 steady or more than 2 casual partners, unsafe anal sex or other high-risk sexual techniques, and enema use were associated with the presence of any of the following STI: CT, NG, or syphilis. Routine (bi-) annual screening for anal STI and syphilis, in HIV⁺ MSM reporting any of the factors associated with STI in this study, might be considered to prevent the further spread of STI.