Antibiotics for treating urogenital Chlamydia trachomatis infection in men and non-pregnant women

Abstract

Background: The genital infection caused by Chlamydia trachomatis (CT) is a common sexually transmitted infection (STI) globally. The infection is mainly asymptomatic in women, thus it can produce infertility and chronic pelvic pain. In men infection is mainly symptomatic, but can evolve to prostatitis. Clinical practice guidelines for CT urogenital infections do not give any specific recommendation about which antibiotic use as first option Objectives: To assess the efficacy and safety of antibiotic treatment for CT genital infection in men and non-pregnant women. Search methods: The Cochrane Sexually Transmitted Infections' (STI) Information Specialist developed the electronic searches in electronic databases (CENTRAL, MEDLINE, Embase and LILACS), and trials registers. We searched studies published from inception to June 2018. Selection criteria: We included parallel, randomised controlled trials (RCTs) of men, and sexually-active, non-pregnant women with CT infection (urethritis or uterine cervicitis or asymptomatic), diagnosed by cell culture for CT, nucleic acid amplification tests (NAAT) or antigen-based detection methods, who had been treated with any of the antibiotic regimens recommended by any of the updated to 2013 CT Guidelines. Data collection and analysis: Four review authors screened evidence according to selection criteria and independently extracted data and assessed risk of bias. Two authors developed the 'Summary of findings' tables. We used a fixed-effect meta-analysis model for combining data where it was reasonable to assume that studies were estimating the same underlying treatment effect. We estimated the pooled risk ratio in order to establish the effects of the comparisons. Our primary outcomes were microbiological failure and adverse events, and our secondary outcomes were clinical failure, antimicrobial resistance and reinfection. Main results: We selected 14 studies ( 2715 participants: 2147 (79.08%) men and 568 (20.92%) women). The studies were conducted mainly at STD clinics. Sample sizes ranged from 71 to 606 participants; follow-up was 29.7 days on average. For the comparison: azithromycin single dose versus doxycycline once or twice daily for 7 days, in men treated for CT, the risk of microbiological failure was higher in the azithromycin group (RR 2.45, 95% CI 1.36 to 4.41; participants = 821; studies = 9; moderate-quality evidence), but regarding clinical failure, the results showed that the effect is uncertain (RR 0.94, 95% CI 0.43 to 2,05; I2 = 55%; participants = 525; studies = 3; low-quality evidence). Regarding adverse events (AE) in men there could be little or no difference between the antibiotics (RR 0.83, 95% CI 0.67 to 1.02; participants = 1424; studies = 6; low-quality evidence). About women treated for CT, the effect on microbiological failure was uncertain (RR = 1.71, 95% CI 0.48 to 6.16; participants = 338; studies = 5; very low-quality evidence). There were no studies assessing clinical failure or adverse events in women, however, we found that azithromycin probably has fewer adverse events in both genders (RR 0.83, 95% CI 0.71 to 0.98; I2 = 0%; participants = 2261; studies = 9; moderate-quality evidence). For the second comparison: doxycycline compared to ofloxacin, for men treated for CT the effect on microbiological failure was uncertain (RR 8.53, 95% CI 0.43 to 167.38, I2 not applicable; participants = 80; studies = 2; very low-quality evidence), as also it was on clinical failure (RR 0.85, 95% CI 0.28 to 2.62; participants = 36; studies = 1; very low-quality evidence). The effect of in women on clinical failure was uncertain (RR 0.94, 95% CI 0.39 to 2.25; I2 = 39%; participants = 127; studies = 2; very low-quality evidence).Regarding adverse events, the effect in both men and women was uncertain (RR 1.02 95% CI 0.66 to 1.55; participants = 339 studies = 3; very low-quality evidence). The effect on microbiological failure in women and in men and women together, the effect on microbiological failure was not estimable. The most frequently AE reported were not serious and of gastrointestinal origin.No studies assessed antimicrobial resistance or reinfection in either comparison. Authors' conclusions: In men, regimens with azithromycin are probably less effective than doxycycline for microbiological failure, however, there might be little or no difference for clinical failure. For women, we are uncertain whether azithromycin compared to doxycycline increases the risk of microbiological failure. Azithromycin probably slightly reduces adverse events compared to doxycycline in men and women together but may have little difference in men alone. We are uncertain whether doxycycline compared to ofloxacin reduces microbiological failure in men or women alone, or men and women together, nor if it reduces clinical failure or adverse events in men or women. Based on the fact that women suffer mainly asymptomatic infections, and in order to test the effectiveness and safety of the current recommendations (azithromycin, doxycycline and ofloxacin), for CT infection, especially in low and middle income countries, future RCTs should be designed and conducted to include a large enough sample size of women, and with low risk of bias. It is also important that future RCTs include adherence, CT resistance to antibiotic regimens, and risk of reinfection as outcomes to be measured. In addition, it is important to conduct a network meta-analysis in order to evaluate all those studies that included in one arm only the current antibiotic treatments for CT infection that are recommended by the updated clinical practice guidelines.