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Epidemiology
HIV and syphilis prevalence and associated risk factors among fishing communities of Lake Victoria, Uganda Gershim Asiki,1 Juliet Mpendo,2 Andrew Abaasa,1 Collins Agaba,1 Annet Nanvubya,2 Leslie Nielsen,2 Janet Seeley,1,3 Pontiano Kaleebu,1,2 Heiner Grosskurth,1,4 Anatoli Kamali1 < Additional materials are
published online only. To view these files please visit the journal online (http://sti.bmj. com). 1
Medical Research Council (MRC)/Uganda Virus Research Institute (UVRI)dUganda Research Unit on AIDS, Entebbe, Uganda 2 UVRI/International Aids Vaccine Initiative (IAVI)dHIV Vaccine Program, Entebbe, Uganda 3 School of International Development, University of East Anglia, Norwich, UK 4 London School of Hygiene and Tropical Medicine, London, UK Correspondence to Gershim Asiki, Medical Research Council Research Unit on AIDS, Uganda Virus Research Institute, PO Box 49 Entebbe, Uganda;
[email protected] Accepted 17 June 2011 Published Online First 10 August 2011
ABSTRACT Objectives Recent publications suggest that fishing populations may be highly affected by the HIV epidemic. However, accurate data are scarce. The authors determined HIV and syphilis prevalence and associated risk factors in a fishing population of Lake Victoria in Uganda. Methods 10 188 volunteers aged $13 years from a census carried out in five fishing communities between February and August 2009 were invited to attend central study clinics established in each community. After informed consent, 2005 randomly selected volunteers responded to socio-demographic and risk assessment questions, provided blood for HIV testing and 1618 volunteers were also tested for syphilis. Risk factors were analysed using logistic regression. Results HIV and active syphilis (rapid plasma reagin titre $1:8) prevalences were 28.8% (95% CI 26.8 to 30.8) and 4.3% (95% CI 3.3 to 5.4), respectively, and high risk sexual behaviour was frequently reported. HIV prevalence was independently associated with female sex, increasing age, occupation (highest in fishermen), relationship to household head, self-reported genital sores and knowledge of an HIV infected partner. Alcohol consumption, syphilis and sexually transmitted infections (STIs) reported by health workers were associated with HIV in women, and genital discharge and inconsistent condom use in men. Syphilis prevalence was independently associated with age and alcohol consumption in women, and recent genital sores and sex under the influence of drugs in men. Conclusion This fishing population characterised by a very high HIV prevalence, high syphilis prevalence and frequently reported sexual risk behaviours, urgently needs improved STI services and targeted behavioural interventions.
INTRODUCTION Fisher-folk have been described as vulnerable to HIV infection and other sexually transmitted infections (STIs).1e4 In Uganda, as in other countries in sub-Saharan Africa, HIV/AIDS prevention and treatment services have not yet effectively reached fishing communities. Risk behaviour and infection rates are believed to be high; however, there is a paucity of robust data.5 6 We addressed this information gap by examining HIV and syphilis prevalence and associated risk factors in a fishing population from Uganda. Sex Transm Infect 2011;87:511e515. doi:10.1136/sti.2010.046805
METHODS In order to identify participants for a cohort study to determine HIV incidence and to assess their suitability for future intervention studies including HIV vaccine research, a cross-sectional study was conducted among a representative sample of adults from five intentionally selected fishing communities situated on the shores of Lake Victoria in southwest Uganda. This provided an opportunity to investigate the prevalence of HIV infection and serosyphilis, and the risk factors associated with these infections. Detailed study objectives of this larger study and the criteria used for the selection of communities and participants are provided in the online supplementary material. Between February and August 2009, a census was conducted in these communities and a random sample of individuals aged $13 years (see online supplementary material), stratified by sex and age groups to reflect census distribution, were invited to attend central study clinics, one of which was established in each community. Consenting participants were interviewed on demographic factors, sexual behaviour and recently experienced STIs. Blood samples were collected to test for HIV and serological syphilis. A rapid HIV test was performed (Determine; Abbott Laboratories, Diagnostic division, Illinous, Chicago USA) and all positive specimens were confirmed by two independent ELISA tests (Vironostika HIV Uni-Form II plus 0 microelisa system, Biome9 rieux, Boxtel, The Netherlands) and Murex HIV-1.2.0 Murex, Biotech Limited, Dartford, UK) and by western blotting if indeterminate. The rapid plasma reagin test (RPR; Biotec Laboratories Limited, Ipswich, Suffolk, UK) was used to test for syphilis and if positive was confirmed by the Treponema pallidum haemagglutination assay (TPHA; Biotec Laboratories Limited Ipswich Suffolk, UK). Specimens with positive RPR and TPHA test results were defined as indicative of active syphilis if the RPR titre was $1:8. Univariable analyses were carried out separately for men and women. A likelihood ratio test (p
