Neiserria gonorrhoeae and Chlamydia trachomatis infection


Among MSM attending Australian sexual health clinics in 2017, chlamydia and gonorrhoea incidence was approximately 60% higher among HIV-positive MSM, compared with HIV-negative, MSM (3).   In the previous five years, chlamydia incidence increased by 25% and 43% among HIV-positive and HIV-negative MSM, respectively. Over the same time period, gonorrhoea incidence also increased among HIV‑positive (31%) and HIV‑negative (34%) MSM (3).

These increases were observed during a time of rapid HIV pre-exposure prophylaxis roll-out in several Australian jurisdictions (8, 9).  The concurrent increase in STI testing frequency undoubtedly contributed to these increases. Nonetheless, a significant increase in chlamydia incidence was observed in the Victorian PrEP Demonstration Project, even when adjusted for pre-PrEP STI testing frequency (10).

 Clinical presentation

In a US cross-sectional study of women hospitalised with pelvic inflammatory disease (PID), HIV-positive women had a more severe initial presentation and prolonged hospital course compared with hospitalised HIV-negative women (11). Nonetheless, there was no difference by HIV status in the prevalence of chlamydia and gonorrhoea detected during hospitalisation, or for treatment outcomes with standard therapeutic regimens. There have been no other published studies evaluating differences in clinical presentation, diagnosis, or response to treatment of gonococcal or chlamydial infections in patients with HIV infection (12).


 Australian guidelines have recently changed to recommend 2g oral Azithromycin (previously 1g) plus 500mg IMI Ceftriaxone statim for treatment of pharyngeal gonococcal infections. Compared with uncomplicated anogenital infection (where treatment guidelines remain unchanged), treatment of pharyngeal gonorrhoea may be more likely to select for both ceftriaxone and azithromycin resistance due to lower levels of drug penetration at this site with treatment failures being observed, even in gonococcal strains susceptible to both antibiotics. The rise in low-level resistance to azithromycin among Australian gonococcal isolates is the basis for the recommendation to increase the dose of oral azithromycin (4).

A recent systematic review and meta-analysis suggested that one week of oral doxycycline 100mg BD was superior to a single dose of Azithromycin 1g po statim, for treatment of rectal chlamydia in MSM (13) and a randomized clinical trial will soon definitely answer this question for treatment of asymptomatic rectal chlamydia in MSM (14).