Evaluation of the ultrasensitive human immunodeficiency virus type 1 (HIV-1) p24 antigen assay performed on dried blood spots for diagnosis of HIV-1 infection in infants.

The diagnostic accuracy of the modified p24 antigen assay performed on pediatric dried blood spots was evaluated. Samples analyzed within 6 weeks of collection yielded no false-positive results (specificity, 100%) and few false-negative results (sensitivity, 96.5% to 98.3%). Laboratory services with limited resources should assess this option for routine infant diagnosis.

Low risk of contamination with automated and manual excision of dried blood spots for HIV DNA PCR testing in the routine laboratory.

In low resource settings the inability to diagnose HIV in infants early presents a major obstacle to providing care for HIV-infected children. Dried blood spot samples offer a solution to the scarcity of skills available for venesecting young infants but pose challenges to laboratories because their processing requirements are distinct from that of the liquid blood samples widely used for viral detection assays. Different methods of excising 287 paired HIV-positive and HIV-negative dried blood spot samples (n=574) for testing by the Roche Amplicor HIV-1 DNA assay version 1.5 were assessed. A manual punch in conjunction with three different cleaning protocols (n=372) and an automated punch (BSD 1000 GenePunch) using a single cleaning protocol (n=202) was assessed for the risk of cross contamination between samples. A single false positive result obtained using the automated punch may have been attributable to contamination during the excision step of the assay. Excision of dried blood spot samples is associated with a very low risk of cross contamination regardless of the instrument or cleaning intervention used. The process of excising dried blood spot samples should not compromise the results of HIV viral detection assays performed on dried blood spots in routine laboratories which is encouraging for increasing access to an accurate diagnosis of HIV in infants.

Evaluation of dried whole blood spots obtained by heel or finger stick as an alternative to venous blood for diagnosis of human immunodeficiency virus type 1 infection in vertically exposed infants in the routine diagnostic laboratory.

The diagnostic accuracy of the Roche Amplicor human immunodeficiency virus type 1 DNA PCR assay (version 1.5) on DNA extracted from pediatric heel prick dried blood spots using Roche MagNA Pure nucleic acid purification technology was evaluated. The methodologies transfer successfully from the labor-intensive research laboratory to the high-throughput automated routine laboratory.

Ultrasensitive human immunodeficiency virus type 1 p24 antigen assay modified for use on dried whole-blood spots as a reliable, affordable test for infant diagnosis.

The ultrasensitive human immunodeficiency virus (HIV) p24 antigen assay was modified for use on pediatric dried whole-blood spots on Whatman no. 1 filter paper. The modified assay was found to be reliable and accurate, making it an affordable tool for pediatric HIV diagnosis in developing countries.