Schistosoma mansoni and HIV acquisition in fishing communities of Lake Victoria, Uganda: a nested case-control study.

Ali Ssetaala,Nassim Kyakuwa,Juliet Mpendo,Anatoli Kamali,Govert J Van Dam,Jessica Nakiyingi‐Miiro,Leslie Nielsen,Pontiano Kaleebu,Noah Kiwanuka,Paul L Corstjens,Gershim Asiki,Alison M Elliott,Pietro Pala,Jan De Bont,Giuseppe Pantaleo

doi:10.1111/tmi.12531

Abstract

ObjectiveIt has been suggested that Schistosoma mansoni, which is endemic in African fishing communities, might increase susceptibility to human immunodeficiency virus (HIV) acquisition. If confirmed, this would be of great public health importance in these high HIV‐risk communities. This study was undertaken to determine whether S. mansoni infection is a risk factor for HIV infection among the fishing communities of Lake Victoria, Uganda. We conducted a matched case–control study, nested within a prospective HIV incidence cohort, including 50 HIV seroconverters (cases) and 150 controls during 2009‐2011.Methods S. mansoni infection prior to HIV seroconversion was determined by measuring serum circulating anodic antigen (CAA) in stored serum. HIV testing was carried out using the Determine rapid test and infection confirmed by enzyme‐linked immunosorbent assays.ResultsAbout 49% of cases and 52% of controls had S. mansoni infection prior to HIV seroconversion (or at the time of a similar study visit, for controls): odds ratio, adjusting for ethnicity, religion, marital status, education, occupation, frequency of alcohol consumption in previous 3 months, number of sexual partners while drunk, duration of stay in the community, and history of schistosomiasis treatment in the past 2 years was 1.23 (95% CI 0.3–5.7) P = 0.79. S. mansoni infections were chronic (with little change in status between enrolment and HIV seroconversion), and there was no difference in median CAA concentration between cases and controls.ConclusionsThese results do not support the hypothesis that S. mansoni infection promotes HIV acquisition.

Highlights

Fishing communities in Uganda are disproportionately affected by human immunodeficiency virus (HIV) infection with incidence and prevalence four times the national average, or more [1, 2]
S. mansoni infections were chronic, and there was no difference in median circulating anodic antigen (CAA) concentration between cases and controls
Determination of S. mansoni infection status was based on serum CAA

Summary

Introduction

Fishing communities in Uganda are disproportionately affected by HIV infection with incidence and prevalence four times the national average, or more [1, 2]. These figures are attributed to high-risk sexual behaviour and limited access to health services [1, 2]. Proposed systemic immunological mechanisms for this include upregulation of HIV co-receptors and of Th2 T cells in which HIV may replicate more efficiently [3, 8] If confirmed, this would imply that control of S. mansoni, as well as of S. haematobium, could contribute to reducing the HIV reservoir among fishing communities and spread to the general population

Methods

Results

Conclusion