Low Prevalence Rate of Indeterminate Serological Human Immunodeficiency Virus Results among Pregnant Women from Burkina Faso, West Africa

Rapid human immunodeficiency virus (HIV) antibody tests have been adopted into national guidelines for HIV testing in many countries in sub-Saharan Africa. One goal of HIV rapid testing is to minimize the occurrence of indeterminate results. From January 2005 to December 2007, plasma (or serum) samples from pregnant women in Bobo-Dioulasso (Burkina Faso, West Africa) were screened for HIV by using two rapid tests (the Determine HIV1/2 test [Abbott] and Genie II HIV-1/HIV-2 [Bio-Rad]) through a sequential algorithm prior to enrollment of HIV-1-infected women in a prevention of mother-to-child transmission (PMTCT) trial (WHO/ANRS 1289 Kesho Bora trial). Samples exhibiting indeterminate results (Determine positive and Genie II negative) were further tested with a fourth-generation HIV enzyme immunoassay (EIA) (Murex HIV Ag/Ab combination in 2005 and 2006 and Vironostika HIV Uni-Form II Ag/Ab in 2007). If positive, they were finally assessed for HIV-1 RNA (Generic HIV-1 RNA viral load assay; Biocentric). From a total of 44,653 samples tested, 597 (1.3%) showed indeterminate results. Of these, 367 could be analyzed by EIA. Only 15 (15/367, 4.1%) samples were found EIA reactive. Of these, 11 could be tested for HIV-1 RNA. All were HIV-1 RNA negative. In our clinical practice, pregnant women with such indeterminate results are now reassured during posttest counseling that they are very unlikely to be infected with HIV-1. As a consequence, such women with indeterminate results can reliably be considered negative when urgent clinical decisions (such as providing PMTCT prophylaxis) need to be taken.