RAPID SCREENING FOR EARLY DETECTION OF MOTHER-TO-CHILD TRANSMISSION OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1

The testing of dried blood spots (DBSs) for the presence of human immu nodeficiency type 1 (HN 1) proviral DNA by PCR was first described in 1991. The technology has proven to be particularly valuable for resolv ing the infection status in HIV-1-indeterminate infants born to HIV-1- seropositive mothers. To broaden the applicability of DBS PCR, we adap ted it to a standardized, commercially available microwell plate ampli fication and detection kit, Amplicor HIV-1, produced by Roche Diagnost ic Systems. The microwell assay is rapid and easy to perform and uses equipment that is readily available in routine diagnostic laboratories . The high level of performance of the assay was demonstrated in 1,168 duplicate tests performed on 584 DBSs from 178 uninfected and 100 HIV -1-infected individuals, including 56 children with perinatally acquir ed HIV-1. Of 12 infants who were followed prospectively from birth, 3 (25%) were infected in utero (PCR positive at birth) and 9 (75%) were infected intrapartum (PCR negative, culture negative at birth). Overal l, HTV-1 DNA was identified in 3 of 11 (27.3%) DBSs collected from inf ected infants during the first 4 days of life, 8 of 9 (88.9%) DBSs col lected between 10 and 15 days postpartum, and 166 of 167 (99.4%) DBSs collected after 15 days of age. All 320 DBSs from uninfected children were PCR DNA negative. These findings indicate that use of the Roche m icrowell DBS PCR assay provides a powerful new approach for large-scal e perinatal screening programs and population-based studies of vertica l transmission.