Gonorrhoea: New diagnostics and treatment guidelines

The 2021 WHO GLASS reports shows that the proportion of patients with genital infections caused by resistant Neisseria gonorrhoeae are extremely high for ciprofloxacin. There are intermediate rates of resistance against azithromycin, primarily used to treat individuals with genital chlamydial infections. There is decreased susceptibility against ceftriaxone which is an injectable but is the first line drug recommended by WHO and in many countries because of widespread resistance to quinolones. An accurate rapid test combined with susceptibility or resistance testing is urgently needed so that doctors can be informed about what drug to use.

Proportion of patients with genital infections caused by resistant N. gonorrhoeae

(Click to expand)

Source: Global Antimicrobial Resistance and Use Surveillance System (GLASS) Report June 2021. Click here for link.

What is new in the diagnosis of gonococcal infections?

The winner of the US NIH AMR prize is the Visby diagnostic test which is used for the detection of N.gonorrhoeae, C trachomatis, and T vaginalis. This test is a single-use, disposable, fully-integrated, rapid molecular point-of-care test (the Visby Medical Sexual Health Test [Visby Medical, San Jose, CA, USA]) for the:

• rapid (providing results in <30 min), easy-to-use
• Study limitations included 7% of point-of-care test results being invalid on the initial run, 6–7% of results from the investigational device being non-evaluable for the different STIs

The Dare-to-dream scenario for NG diagnostics:

Although the ability to use genital or ocular specimens for detection of all 3 diseases is useful, treatment choices are dependent on their drug susceptible patterns.

Turner et al modelled scenarios where a test that can detect N. gonorrhoeae and the presence of resistance gene encoding for quinolone and penicillin within 30 minutes, then clinicians can go back to using oral regimens such as penicillin and fluoroquinolones, which are much cheaper and would be a real game changer.

33, 431 ceftriaxone treatments are given annually in the UK for gonorrhoea (2014). Antibiotic susceptibility testing was performed on all available NG isolates

A modelling study showed that if a 30 min AMR POC test were available:

• for NG + penicillin resistance, 79% of current treatment could be replaced by penicillin
• for GC + ciprofloxacin resistance, 66% of current treatment could be replaced by ciprofloxacin

AMR POC test can:

✓ reduce loss to follow up
✓ extend the life of current last-line treatment V be cost-saving