Mouthwash to prevent pharyngeal gonorrhoea – a study of adherence and acceptability.

Background
Gonorrhoea infections amongst men who have sex with men (MSM) are at a 20-year high, and antibiotic resistance is also increasing. Pharyngeal gonorrhoea is an important contributor to gonorrhoea transmission, and gonorrhoea acquires genes that confer antibiotic resistance from other pharyngeal bacteria.

Aim
This study assessed whether men who have sex with men (MSM) would adhere to a regimen of daily mouthwash use, as a new intervention to prevent pharyngeal gonorrhoea.

Methods
Ten MSM at Melbourne Sexual Health Centre were invited to use Listerine® alcohol-containing mouthwash daily for 14 days in August 2015. Participants were asked to complete baseline and follow-up questionnaires about their experience of mouthwash use, and a daily diary to record mouthwash use over the 14-day study period. 

Results
The participants’ mean age was 28 years (SD 7.2). Mouthwash was used at least once daily for 133 of 140 days (95% of days; 95% CI: 90% to 98%). All ten men reported willingness to use mouthwash on a daily basis, and nine men were willing to use mouthwash after oral sex.

Conclusion
This study showed a high adherence to daily use of mouthwash and that it is an acceptable intervention to reduce the risk of pharyngeal gonorrhoea in MSM. Further studies are required to assess whether Listerine® mouthwash is effective against pharyngeal gonorrhoea in vitro and in vivo. If this is confirmed, then this will be a novel strategy to reduce transmission of gonorrhoea amongst MSM and may potentially also reduce rates of antimicrobial resistance.

Adherence to and acceptability of mouthwash as a potential preventive intervention for pharyngeal gonorrhoea among men who have sex with men in Australia – an observational study.