Background:

Inconclusive serodiagnosis of HIV infection is particularly frequent in Central Africa.

The aims of this study were to:

(i) determine the rate of inconclusive results with the two-test algorithm that the WHO proposed in 1997 (WHO II) versus the three-test algorithm (revised in 2012 and consolidated in 2015 by WHO) for HIV testing, and (ii) determine the prevalence of HIV-1 and HIV-2 co-infection in the north-eastern region of the Democratic Republic of the Congo (DRC).

Methods:

A multicentre cross-sectional study was performed between March and June 2016 in Kisangani and Bunia, the capital cities of Tshopo and Ituri provinces respectively. Alere Determine HIV-1/2 (Alere Medical Co. Ltd., Japan), Uni-GoldTM HIV (Trinity Biotech Manufacturing Ltd., Ireland) and recomLine HIV-1 and HIV-2 IgG (Biosynex, France) were the first, second and third tests in the serial algorithm.

Results :

The rate of inconclusive results was 1.1% (95% CI: 0.4 to 3.1) with the two-test algorithm and 0.4% (95% CI: 0.1 to 2.1) with the three-test algorithm (p less than 0.001). The prevalence of HIV-1 and HIV-2 co-infection among HIV positive sera was 16.7% (95% CI: 4.7 to 44.8).

Conclusion:

The three-test algorithm HIV testing strategy significantly reduces the rate of inconclusive results. In addition, the prevalence of HIV-1 and HIV-2 co-infection is higher in a context where HIV-2 infection is poorly documented. Large-scale research is essential to clarify these results