{'fraction_non_alphanumeric': 0.038777908343125736, 'fraction_numerical': 0.02555816686251469, 'mean_word_length': 5.168478260869565, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
HIV status does not contribute to response to syphilis treatment

Sir: Warwick et al. fail to answer the question posed in the title of their article: whether HIV-positive and HIV-negative individuals should be treated differently. While we agree that a randomized control trial of standard versus extended penicillin treatment for syphilis would allow us to determine optimal therapy and duration, funding for such a study will prove difficult to obtain. During the Dublin syphilis outbreak, we diagnosed and treated 506 individuals (HIV-positive, n 1⁄4 100) with their first episode of syphilis between January 2000 and June 2003 and attempted to follow all patients for two years. Ninety-one percent of HIV-positive individuals were followed for two years compared with 77% of HIV-negative individuals. Only 10% of HIV-positive individuals were immunosuppressed (CD4 , 200 cells/10). Unlike the Brighton group, patients were treated with penicillin treatments according to syphilis stage and presentation, with ‘extended course treatment’ given only to those with positive cerebrospinal fluid or clinical symptoms suggestive of neurosyphilis. Responders were defined as a fourfold decline in titre from baseline or seroreversion (i.e. rapid plasma reagin negative). HIV-negative individuals were most frequently treated with benzathine penicillin (HIV negative 84% versus HIV positive 34%), with a smaller proportion treated with procaine penicillin 0.9 MU IM for 10 days (HIV negative 9% versus HIV positive 43%) and procaine penicillin 1.8 MU IM and probenicid for 21 days (HIV negative 5% versus HIV positive 17%). On an intent-to-treat analysis (where missing equalled failure), HIV-positive individuals responded better to treatment compared with HIV-negative individuals with overall response rates of 76 and 64%, respectively (P 1⁄4 0.02). Where all those who were lost to follow-up were excluded, response rates were identical (HIV positive 76/91 [84%] compared with HIV negative 258/312 [83%]). In addition, there was no statistically significant difference in response rate and type of treatment within HIV-positive individuals. Over the subsequent two years, 17 individuals who were initial responders had serological relapse, all of whom had potential high-risk exposure within syphilis networks. On multivariate analysis, where missing equalled failure, controlling for treatment type, early syphilis stage (adjusted odds ratio [OR] 3.7, 95% confidence intervals [CIs] 2.6–5.9) and being HIV positive were significant predictors of response to therapy (adjusted OR 2.0 [95% CI 1.1–3.6]). Where those who were lost to follow-up were excluded only early-stage syphilis remained a predictor of response. Warwick et al. demonstrated that HIV-positive individuals were less likely to default from follow-up and successfully responded to 17 days high-dose procaine penicillin and probenicid for early syphilis treatment. In our cohort, similar follow-up rates in HIV patients were observed over a two-year period and response rates to all forms of penicillin treatment were equivalent in both HIV-positive and HIV-negative individuals. We believe that HIV status (in those that are immune competent) does not contribute to treatment response and that HIV-positive individuals can be treated with standard penicillin regimens, particularly where syphilis serology forms part of routine HIV care.