Filippo Uberti

HIV serological screening in a population of pregnant women in the Republic of Congo: suitability of different assays

Different strategies can be applied for the screening of HIV infection, depending on the local seroprevalence. Within a WHO type III strategy, we compared the results of two different second‐line methods for HIV screening of a population of pregnant women in the Republic of Congo. Sera from 3614 consecutive pregnant women were tested for HIV with Genescreen Plus Ag/Ab EIA assay; positive specimens were retested with two different second‐line methods. (Determine HIV‐1/2 rapid test and Vironostika HIV Ag/Ab specific EIA assay). Discordant samples were tested with HIV‐1/2 Western Blot and, if necessary, HIV RNA molecular assay. Of the 3614 sera, 221 were positive with Genscreen. Among them, 21 and 10 tested negative with Vironostika and Determine, respectively. A 100% correspondence with 3rd line confirmation test results was found in Genscreen positive/Vironostika negative samples, whereas a 5.5% overestimation of HIV seroprevalence was observed when Determine, instead of Vironostika, was used as second‐line test. The choice of appropriate assays in adequate sequence, within the correct WHO strategy, is pivotal to minimize the risk of overtreatment of HIV infection.