Simple, sensitive, and specific detection of human immunodeficiency virus type 1 subtype B DNA in dried blood samples for diagnosis in infants in thefield

The detection of virus is used to diagnose human immunodeficiency virus typ e 1 (HIV-1) infection in infants due to the persistence of maternal antibod ies for a year or more. An HIV-1 DNA PCR assay with simple specimen collect ion and processing was developed and evaluated, Whole blood was collected o n filter paper that lysed cells and bound the DNA, eliminating specimen cen trifugation and extraction procedures. The DNA remained bound to the filter paper during PCR amplification. Assays of copy number standards showed rep roducible detection of 5 to 10 copies of HIV-1 in 5 mul of whole blood. The sensitivity of the assay did not decrease after storage of the standards o n filter paper for 3 months at room temperature or after incubation at 37 o r 45 degreesC for 20 h. The primers used for nested PCR of the HIV-1 pol ge ne amplified templates from a reference panel of multiple HIV-1 subtypes bu t did not amplify a subtype A or a subtype C virus from children living in Seattle. The assay had a sensitivity of 98.4% and a specificity of 98.3% fo r testing of 122 specimens from 35 HIV-1-infected and 16 uninfected childre n and 43 seronegative adults living in Washington. The assay had a sensitiv ity of 99% and a specificity of 100% for testing of 102 HIV-1-positive (as determined by enzyme immunoassay) Peruvian women and 6 seropositive and 34 seronegative infants. This assay, with adsorption of whole blood to filter paper and no specimen processing, provides a practical, economical, sensiti ve, and specific method for the diagnosis of HIV-1 subtype B infection in i nfants.