Genital ulcer disease in central Australia: predictors of testing and outcomes

The global and regional burden of genital ulcer disease due to herpes simplex virus: a natural history modelling study

Introduction

Herpes simplex virus (HSV) infection can cause painful, recurrent genital ulcer disease (GUD), which can have a substantial impact on sexual and reproductive health. HSV-related GUD is most often due to HSV type 2 (HSV-2), but may also be due to genital HSV type 1 (HSV-1), which has less frequent recurrent episodes than HSV-2. The global burden of GUD has never been quantified. Here we present the first global and regional estimates of GUD due to HSV-1 and HSV-2 among women and men aged 15-49 years old.

Methods

We developed a natural history model reflecting the clinical course of GUD following HSV-2 and genital HSV-1 infection, informed by a literature search for data on model parameters. We considered both diagnosed and undiagnosed symptomatic infection. This model was then applied to existing infection estimates and population sizes for 2016. A sensitivity analysis was carried out varying the assumptions made.

Results

We estimated that 187 million people aged 15-49 years had at least one episode of HSV-related GUD globally in 2016: 5.0% of the world's population. Of these, 178 million (95% of those with HSV-related GUD) had HSV-2 compared with 9 million (5%) with HSV-1. GUD burden was highest in Africa, and approximately double in women compared with men. Altogether there were an estimated 8 billion person-days spent with HSV-related GUD globally in 2016, with 99% of days due to HSV-2. Taking into account parameter uncertainty, the percentage with at least one episode of HSV-related GUD ranged from 3.2% to 7.9% (120-296 million). However, the estimates were sensitive to the model assumptions.

Conclusion

Our study represents a first attempt to quantify the global burden of HSV-related GUD, which is large. New interventions such as HSV vaccines, antivirals or microbicides have the potential to improve the quality of life of millions of people worldwide.

Prevalence of chlamydia, gonorrhoea, syphilis and trichomonas in Aboriginal and Torres Strait Islander Australians: a systematic review and meta-analysis

Higher notification rates of sexually transmissible infections (STIs) are reported among Aboriginal and Torres Strait Islander (Aboriginal) compared with non-Aboriginal people in Australia. The aim of this study is to estimate the pooled prevalence of chlamydia, gonorrhoea, syphilis and trichomonas among Aboriginal people in Australia by sex, age-group, setting (clinic vs population/community-based) and population group [adults, pregnant females, young people (12-29 years) and prisoners]. The databases Medline, PubMed and Web of Science were searched in May 2015. A meta-analysis was conducted to estimate the pooled prevalence of the four STIs in Aboriginal people and if possible, by gender, age-group, setting and population group. A total of 46 studies were included. The pooled prevalence was 11.2% (95%CI: 9.4-13.0%) for chlamydia (36 studies), 12.5% (95%CI: 10.5-14.6%) for gonorrhoea (28 studies), 16.8% (95%CI: 11.0-22.6%) for syphilis (13 studies) and 22.6% (95%CI: 18.5-26.7%) for trichomonas (11 studies); however, there was significant heterogeneity between studies (I(2) <97.5%, P<0.01). In the subgroup analysis, a higher pooled prevalence occurred in females than males for chlamydia (12.7% vs 7.7%) and gonorrhoea (10.7% vs 8.1%). The prevalence of chlamydia was 12.4% in clinic-based compared with 4.3% in population-based studies. The highest pooled prevalence by population group was among pregnant females (16.8%) and young people (16.2%) for chlamydia, pregnant females (25.2%) for trichomonas; and young people for gonorrhoea (11.9%). This review highlights the need to decrease the prevalence of STIs among Aboriginal people through community-based programs that target asymptomatic young people.