Dual seroreactivity to HIV-1 and HIV-2 in female sex workers in Abidjan, Côte d'Ivoire

Objective
To determine the absolute, and proportional prevalence of dual seroreactivity to HIV-1, and HIV-2 in female sex workers in Abidjan, to determine risk determinants for this serologic profile, and to describe the associated clinical, and immunological characteristics.

Design
Cross-sectional study.

Setting
Confidential clinic for female sex workers in Abidjan.

Participants
Female sex workers.

Main outcome measures
HIV serostatus, CD4+ counts, women with AIDS, behavioural, and sociodemographic characteristics.

Results
Among 1209 women tested, the overall HIV seroprevalence was 80%, while the prevalence of dual seroreactivity was 30%. Dual seroreactivity accounted for 38% of all HIV infections. Compared with women reacting to HIV-1 only, dually seroreactive women were significantly more likely to have been in sex work for a longer period, to be aged ≥20 years, and to charge less money for intercourse. No difference in mean CD4+ count was noted between women with dual seroreactivity (561±106/l), and HIV-1 -seropositive women (588 ± 106/l).

Conclusions
Female sex workers in Abidjan had the highest absolute (30%), and proportional rate (38%) of dual seroreactivity yet described in any population. Increased sexual exposure is associated with an increased risk of dual seroreactivity. Although better molecular diagnostic techniques are required, a substantial proportion of female sex workers in Abidjan is likely to be infected with both HIV-1, and HIV-2.