Impact of male circumcision on the HIV epidemic in Papua New Guinea: a country with extensive foreskin cutting practices.

Richard T Gray,John M Murray,David P Wilson,Angela Kelly-Hanku,Andrew Vallely,Peter Siba,David Maclaren,John Kaldor,

doi:10.1371/journal.pone.0104531

Abstract

The degree to which adult medical male circumcision (MC) programs can reduce new HIV infections in a moderate HIV prevalence country like Papua New Guinea (PNG) are uncertain especially given the widespread prevalence of longitudinal foreskin cuts among adult males. We estimated the likely impact of a medical MC intervention in PNG using a mathematical model of HIV transmission. The model was age-structured and incorporated separate components for sex, rural/urban, men who have sex with men and female sex workers. Country-specific data of the prevalence of foreskin cuts, sexually transmitted infections, condom usage, and the acceptability of MC were obtained by our group through related studies. If longitudinal foreskin cutting has a protective efficacy of 20% compared to 60% for MC, then providing MC to 20% of uncut males from 2012 would require 376,000 procedures, avert 7,900 HIV infections by 2032, and require 143 MC per averted infection. Targeting uncut urban youths would achieve the most cost effective returns of 54 MC per HIV infection averted. These numbers of MC required to avert an HIV infection change little even with coverage up to 80% of men. The greater the protective efficacy of longitudinal foreskin cuts against HIV acquisition, the less impact MC interventions will have. Dependent on this efficacy, increasing condom use could have a much greater impact with a 10 percentage point increase averting 18,400 infections over this same period. MC programs could be effective in reducing HIV infections in PNG, particularly in high prevalence populations. However the overall impact is highly dependent on the protective efficacy of existing longitudinal foreskin cutting in preventing HIV.

Highlights

Based on randomized trials in sub-Saharan Africa, adult medical male circumcision (MC) reduces HIV acquisition in men during heterosexual intercourse by approximately 60% [1,2,3]
The model estimates of numbers of individuals living with HIV infection show a much slower and lower expansion to date and into the future than experienced in sub-Saharan Africa but as indicated by HIV data from Papua New Guinea (PNG) (Figure 2A)
We and others have shown that increased MC in high prevalence countries, where the main mode of HIV transmission is through heterosexual contact, can lead to sizeable reductions in HIV incidence [4,5,6]

Summary

Introduction

Based on randomized trials in sub-Saharan Africa, adult medical male circumcision (MC) reduces HIV acquisition in men during heterosexual intercourse by approximately 60% [1,2,3]. The intervention is considered moderately costeffective requiring between 5 and 15 MC at a cost of $US150 to $US900 to avert an HIV infection [6], other calculations produce higher estimates of 19 to 58 MCs per infection averted [8] Based on this evidence, voluntary MC has become a priority prevention intervention by global funders and countries in southern and eastern Africa [9,10]. A longitudinal cut may confer some degree of protection against HIV acquisition in men in a similar way to full removal of the foreskin, because the lateral retraction and eversion of the foreskin that follows a dorsal slit result in exposure of the glans and inner foreskin, and a final appearance that can closely resemble medical circumcision

Methods

Results

Conclusion