Prevalence of positive syphilis serology among HIV-infected patients: role for routine screening in Thailand.

Data regarding syphilis screening in resource-limited settings is limited. We aimed to determine the prevalence and associated factors of positive syphilis serology in HIV-infected adult patients in an outpatient setting in Thailand. A cross sectional study was conducted among 178 HIV-infected patients. Ninety-eight patients (55%) were male; then median (interquartile range; IQR) age was 43 (36-49) years. The majority of the patients (84.3%) had a heterosexual risk. Three patients (1.7%) had a positive rapid plasma reagin (RPR) test (range, 1:2 to 1:16), 9 (5%) patients had a positive Treponema pallidum particle agglutination (TPPA) test, and 3 patients (1.7%) had positive results on both tests. On multivariate logistic regression analysis, a pruritic papular eruption [odds ratio (OR) 5.37; 95% confidence interval (CI): 1.09-26.38; p = 0.038], current CD4 cell count (OR 1.22, per 50 cells/mm3; 95% CI: 1.01-1.46; p = 0.035), and using abacavir in the current regimen (OR 59.19; 95% CI: 2.15-1,628.68; p = 0.016) were associated with positive syphilis serology. In conclusion, the prevalence of positive syphilis serology among Thai HIV-infected patients was low. Routine screening for syphilis in HIV-infected patients who are asymptomatic may need to be re-considered at the national level in this resource-limited setting.