Factors associated with rectal pH among men who have sex with men.

Background Rectal chlamydia treatment failures up to 22% with azithromycin 1 g have been reported, but low tissue concentrations are unlikely to be the cause. Anecdotally, low rectal pH could reduce rectal azithromycin concentrations, with in vitro studies reporting higher minimum inhibitory concentrations (MICs) with lower pHs for antibiotics used to treat sexually transmissible infections (STIs). Leucocytes arising from an inflammatory immune response could also lower pH and efficacy. We examined factors that may alter rectal pH and potentially influence treatment outcomes. METHODS: We recruited consecutive men who have sex with men (MSM) from a Dutch STI clinic between October 2016 and July 2018 who had not used antibiotics in the past fortnight. Rectal mucus collected under anoscopy using a cotton swab was used to wet a pH indicator strip. Logistic regression was used to examine the association of pH <8.0 to demographic, dietary, sexual health and behaviour data, recent medication use and STI diagnosis. RESULTS: In total, 112 MSM were recruited (median age 37 years). It was found that 45% and 39% of men were HIV positive or had a rectal infection, respectively. And 50% had a rectal pH <8.0, with 27% reporting a pH between 6.0 and 6.5 where treatment failure is thought to occur for azithromycin. The adjusted odds ratio (OR) of a pH <8.0 showed that being aged 36-45 years (OR 6.7; 95%CI: 1.9-23.4) or having high rectal leucocytes in a Gram smear (OR 0.3; 95%CI: 0.1-0.7) were significantly associated with a low and high rectal pH, respectively. CONCLUSIONS: Lower rectal pH among MSM is associated with older age and could influence the rectal pharmacokinetics of azithromycin and other drugs influenced by pH and may therefore affect treatment outcomes.

Sexually transmissible infections among female sex workers in Amsterdam between 2011 and 2016: does risk vary by work location?

Background Female sex workers (FSW) are at risk for sexually transmissible infections (STI). This study aimed to investigate whether the risk for chlamydia and gonorrhoea differs by work location among FSW in Amsterdam. Additionally, trends in STI positivity rates between 2011 and 2016 were assessed. METHODS: This was a retrospective analysis of routinely collected clinical data during STI consultations of FSW by the Prostitution and Healthcare Centre (P&G292). Work location was categorised as window prostitution, escorts/homeworkers, clubs/brothels/private houses/massage salons and other. RESULTS: In total, 7558 STI consultations of 2529 FSW in the period 2011-16 were included. Positivity rates for chlamydia and gonorrhoea were 6.6% and 2.0%, respectively. Infectious hepatitis B virus, syphilis and HIV were diagnosed in <0.2% of consultations. Positivity rates of chlamydia and rectal gonorrhoea differed significantly by work location (P < 0.001). Genital and rectal chlamydia and rectal gonorrhoea were significantly less likely among women working in window prostitution, except for the other-group. Risk factors for STI did not vary by work location. Among women working in window prostitution, positivity rates for oropharyngeal and genital chlamydia and genital gonorrhoea were significantly decreasing between 2011 and 2016 (P trend <0.05). CONCLUSIONS: The higher STI positivity among escorts/homeworkers and FSW in clubs/brothels/private houses/massage salons emphasises the need for extra attention to improve condom use and STI testing in this group. Factors associated with STI did not vary by work location, thus interventions, including those used by P&G292, to reduce STI risk, can be used for women at all work locations.

Increasing trends of lymphogranuloma venereum among HIV-negative and asymptomatic men who have sex with men, the Netherlands, 2011 to 2017.

IntroductionLymphogranuloma venereum (LGV), an invasive form of Chlamydia trachomatis infection, has been reported among (mainly HIV-positive) men who have sex with men (MSM) since 2003. In the Netherlands, LGV testing recommendations changed from selective to universal testing in 2015. Changes in tested populations could have led to incomparable LGV positivity rates over time.AimWe investigated LGV trends among MSM attending Centres for Sexual Health using surveillance data between 2011 and 2017.MethodsLGV positivity was calculated among MSM tested for rectal Chlamydia infection and MSM tested specifically for LGV. With multivariable logistic regression analysis, the association between years and LGV was adjusted for testing indicators and determinants.ResultsWe included 224,194 consultations. LGV increased from 86 in 2011 to 270 in 2017. Among LGV-positives, proportions of HIV-negative and asymptomatic MSM increased from 17.4% to 45.6% and from 31.4% to 49.3%, respectively, between 2011 and 2017. Among MSM tested for rectal chlamydia, LGV positivity increased from 0.12% to 0.33% among HIV-negatives and remained stable around 2.5% among HIV-positives. Among LGV-tested MSM, LGV positivity increased from 2.1% to 5.7% among HIV-negatives and from 15.1% to 22.1% among HIV-positives. Multivariable models showed increased odds ratios and significant positive associations between years and LGV.ConclusionsAlthough increased testing and changes in LGV incidence are difficult to disentangle, we found increasing LGV trends, especially when corrected for confounding. LGV was increasingly attributed to HIV-negative and asymptomatic MSM, among whom testing was previously limited. This stresses the importance of universal testing and continuous surveillance.