Modelling the impact of screening for chlamydia and gonorrhoea in youth and other high-prevalence groups in a resource-limited setting

Rachel T Esra,Leigh F Johnson

doi:10.1007/s00038-020-01351-0

Abstract

ObjectivesModelling the potential impact of screening for chlamydia and gonorrhoea in youth and other populations in a resource-limited setting.MethodsWe extended an agent-based model of heterosexual chlamydia and gonorrhoea transmission in South Africa to investigate the impact of screening strategies in key populations including youth, patients in HIV care, pregnant women and female sex workers (FSWs). Additionally, we compared the modelled impact of a standardised screening programme to results obtained from other published mathematical models of chlamydia screening.ResultsAll strategies resulted in reductions in general and targeted population chlamydia and gonorrhoea transmission. Opportunistic screening of patients in youth and HIV care was shown to be the most effective, and FSW screening was shown to be the most efficient strategy. Differences between models could be attributed to differences in the modelled heterogeneity in sexual behaviour as well as differences in assumptions about immunity following chlamydia recovery.ConclusionsTaking modelling assumptions into account, opportunistic chlamydia and gonorrhoea screening of youth and those in HIV care represents a viable intervention for reducing sexually transmitted infections in the South African population.

Highlights

Curable bacterial sexually transmitted infections (STIs) such as Chlamydia trachomatis and Neisseria gonorrhoea were responsible for 214 million new infections in 2016 (World Health Organisation 2018)
We investigate the impact of opportunistic screening strategies targeting high-risk groups including youth, female sex workers (FSWs), pregnant women and those in human immunodeficiency virus (HIV) care
Based on estimates of low levels of health-seeking behaviours in South African youth, we assumed that only 23% of female and 15% of male youths would be opportunistically screened per annum in a South African setting (Statistics South Africa 2017)

Summary

Introduction

Curable bacterial sexually transmitted infections (STIs) such as Chlamydia trachomatis (chlamydia) and Neisseria gonorrhoea (gonorrhoea) were responsible for 214 million new infections in 2016 (World Health Organisation 2018). Chlamydia and gonorrhoea can result in serious reproductive problems in women (Menon et al 2015). This presents a major global health challenge, in youth, with 14–25-year-olds in the USA accounting for 65% of chlamydia infections and 53% of gonorrhoea infections (Centers for Disease Control and Prevention 2015). Multiple concurrent sexual partners and limited knowledge of sexual health contribute to increased risk of STIs during adolescence (Centre for Disease Control and Prevention 2013). Cervical ectopy during adolescence may place young women at an increased risk of bacterial STI acquisition (Lee et al 2006).

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