Epidemiology and Infection

Table of Contents - 2008 - Volume 136, Issue 04  

Original Papers

Behaviour change and competitive exclusion can explain the diverging HIV-1 and HIV-2 prevalence trends in Guinea–Bissau

W. P. SCHMIDTa1 c1, M. SCHIM VAN DER LOEFFa1a2, P. AABYa3, H. WHITTLEa2, R. BAKKERa4, M. BUCKNERa5, F. DIASa6 and R. G. WHITEa7

a1 Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK

a2 MRC Laboratories, Fajara, The Gambia

a3 Bandim Health Project, Statens Serum Institut, Copenhagen, Denmark

a4 Department of Public Health, Erasmus MC University Medical Center, Rotterdam, The Netherlands

a5 Department of Sociology, Anthropology, and Criminology, Missouri State University, Springfield, MO, USA

a6 Ministry of Health, Bissau, Guinea–Bissau

a7 Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK

Abstract

The aim of this study was to determine whether a temporary rise in sexual risk behaviour during war in Guinea–Bissau could explain the observed trends in HIV-1 and HIV-2 prevalence, and to explore the possible contribution of competitive elimination of HIV-2 by HIV-1. A simulation model of the heterosexual transmission of sexually transmitted infections was parameterized using demographic, behavioural and epidemiological data from rural Guinea–Bissau, and fitted to the observed HIV-1 and HIV-2 trends with and without a historic rise in risk behaviour. The observed trends could only be simulated by assuming a temporary rise in risk behaviour. Around 30% of the projected decline in HIV-2 prevalence from a peak of 8·7% to 4·3% in 2010 was due to competitive elimination by HIV-1. Importantly for public health, HIV-1 prevalence was predicted to continue increasing and to become the dominant HIV type by 2010. Data collection is required to validate this prediction.

(Accepted April 20 2007)

(Online publication June 11 2007)

Correspondence:

c1 Author for correspondence: Dr W. P. Schmidt, Disease Control and Vector Biology Unit, Department for Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, WC1E 7HT, London UK. (Email: Wolf-Peter.Schmidt@lshtm.ac.uk)

Metrics
Related Content