First HIV prevalence estimates of a representative sample of adult sub-Saharan African migrants in a European city. Results of a community-based, cross-sectional study in Antwerp, Belgium

Abstract

IntroductionWhile sub-Saharan African migrants are the second largest group affected by HIV in Europe, sound HIV prevalence estimates based on representative samples of these heterogeneous communities are lacking. Such data are needed to inform prevention and public health policy.MethodsThis community-based, cross-sectional study combined oral fluid HIV testing with an electronic behavioral survey. Adopting a two-stage time location sampling HIV prevalence estimates for a representative sample of adult sub-Saharan African migrants in Antwerp, Belgium were obtained. Sample proportions and estimated adjusted population proportions were calculated for all variables. Univariable and multivariable logistic regression analysis explored factors independently associated with HIV infection.ResultsBetween December 2013 and October 2014, 744 sub-Saharan African migrants were included (37% women). A substantial proportion was socially, legally and economically vulnerable: 21% were probably of undocumented status, 63% had financial problems in the last year and 9% lacked stable housing. Sexual networks were mostly African and crossed national borders, i.e. sexual encounters during travels within Europa and Africa. Concurrency is common, 34% of those in a stable relationship had a partner on the side in the last year. HIV prevalence was 5.9%(95%CI:3.4%-10.1%) among women and 4.2% (95%CI:1.6%-10.6%) among men. Although high lifetime HIV testing was reported at community level (73%), 65.2% (CI95%:32.4%-88.0%) of sub-Saharan African migrants were possibly undiagnosed. Being 45 years or older, unprotected sex when travelling within Europe in the last year, high intentions to use condoms, being unaware of their last sexual partners’ HIV status, recent HIV testing and not having encountered partner violence in the last year were independently associated with HIV infection in multivariable logical regression. In univariable analysis, HIV infection was additionally associated to unemployment.ConclusionsThis is the first HIV prevalence study among adult sub-Saharan African migrants resettling in a European city based on a representative sample. HIV prevalence was high and could potentially increase further due to the high number of people with an undiagnosed HIV infection, social vulnerability, high levels of concurrency and mainly African sexual networks. Given this population’s mobility, an aligned European combination prevention approach addressing these determinants is urgently needed.

The role of mobility in sexual risk behaviour and HIV acquisition among sub-Saharan African migrants residing in two European cities

“…This study draws on data from two cross-sectional bio-behavioural surveys conducted in Lisbon [21] and Antwerp [16] aiming to assess HIV prevalence, sexual risk behaviours and its determinants among SAM. Both bio-behavioural surveys adopted a similar community-based participatory research approach.…”

“…The Belgian survey used a two-stage time location sampling to recruit study participants. Sampling and recruitment procedures are described in detail elsewhere [16]. In brief, venues were selected with a probability proportion-to-size from the venues' sampling frame.…”

“…In a society characterised by increasing mobility [14], migrants may also travel after having settled in host countries for several reasons, such as social connections or family ties, the search for work or documents. The available evidence shows that travelling is associated with having new sexual partners, engaging in risky sexual behaviours, and becoming part of local sexual networks [12,15,16]. For instance, a study among ethnic minorities living in Amsterdam revealed that participants were exposed to substantial HIV risk while visiting their homelands [17].…”

Who Falls Between the Cracks? Identifying Eligible PrEP Users Among People With Sub-saharan African Migration Background Living in Antwerp, Belgium

“…We performed a secondary analysis of data from a representative community-based bio-behavioral cross-sectional survey (i.e. TOGETHER study) to assess HIV prevalence, conducted in 2013-2014 in Antwerp (1). These data are the most recent behavioral data available for this sub-population in Belgium.…”

Clinical round-up

“…Loos  et al in Belgium3 looked at HIV prevalence among migrants from sub-Saharan Africa in Antwerp using time location sampling over a period of 9 months in 2013–2014. Despite high rates of lifetime testing (73%) among the 744 surveyed, a high undiagnosed fraction, 65.2% (95% CI 32.4% to 88.0%), was seen.…”