Selective testing missed more than two-thirds of all oropharyngeal Neisseria gonorrhoeae infections in women, according to a study published in the Lancet Infectious Diseases. While the findings indicated that routine universal testing is necessary to detect the majority of infections, the study authors noted that the cost-effectiveness of this recommendation warrants further consideration.
In this retrospective cohort study, the study authors assessed the optimal testing strategy for oropharyngeal N gonorrhoeae using surveillance data from all sexually transmitted infection clinics in the Netherlands for a 10-year period. The prevalence of oropharyngeal N gonorrhoeae was compared using 3 different testing strategies: routine universal testing (defined as >85% of women tested per clinic-year), selective testing (defined as 5%-5% of women tested per clinic-year), and incidental testing (<5% of women tested per clinic-year).
Of the 545,750 consultations included in the analysis, 10.5% were defined as routine universal testing, 81.4% were defined as selective testing, and 8.1% were defined as incidental testing. The prevalence of oropharyngeal N gonorrhoeae was similar between consultations done in the routine universal testing group and selective testing group: 1.4% (95% CI, 1.3%-1.5%; n=703/50,962) and 1.4% (95% CI, 1.3%-1.5%; n=1858/132,276), respectively. However, compared with consultations done in the routine universal testing group, the prevalence was higher among consultations done in the incidental testing group (2.8%; 95% CI, 1.9%-3.9%; n=30/1088; P <.0001).
When the authors extrapolated the prevalence in the routine universal testing group (1.4%) to all consultations defined as selective testing including those without oropharyngeal testing (n=444,283), there was an estimated 6221 infections. Of the estimated 6221 infections, 30% (n=1858) were diagnosed using selective testing in clinical practice. Thus, selective testing would have missed an estimated 70% (95% CI, 69%-71%; n=4363/6221) of all oropharyngeal N gonorrhoeae infections, “indicating that routine universal testing is necessary to detect the majority of infections,” the authors noted.
Oropharyngeal-only infections were more prevalent than concurrent genital or anorectal infections across all testing strategies that led to a diagnosis of oropharyngeal N gonorrhoeae infection (n=2591). The prevalence of oropharyngeal-only infections in each group was as follows: 47.7% (n=33/703) in the routine testing group, 53.3% (n=991/1858) in the selective testing group, and 60.0% (n=18/30) in the incidental testing group.
Reporting sex work, being notified of any sexually transmitted infections, and having concurrent genital or anorectal N gonorrhoeae were independent risk factors for oropharyngeal N gonorrhoeae. Meanwhile, reporting sex work and self-identifying as a swinger were independent risk factors for oropharyngeal-only N gonorrhoeae.
Given that the prevalence in both routine universal testing and selective testing strategies was low (1.4%), future studies are needed to assess the cost-effectiveness of routine universal testing. In addition, more studies are needed to determine what the impact of missing or failing to treat oropharyngeal-only infections will have on the control of antimicrobial resistance.
While this study had a large dataset, it was limited by including sexually transmitted infection clinics from only 1 country. In addition, women visiting general practitioners, who diagnose two-thirds of all N gonorrhoeae infections in the Netherlands, were not included.
van Liere GAFS, Dukers-Muijrers NHTM, Kuizenga-Wessel S, Wolffs PFG, Hoebe CJPA. Routine universal testing versus selective or incidental testing for oropharyngeal Neisseria gonorrhoeae in women in the Netherlands: a retrospective cohort study. Lancet Infect Dis. Published online January 11, 2021. doi:10.1016/S1473-3099(20)30594-6