Promising antibody testing strategies for early infant HIV infection diagnosis in China

Stability of Human Immunodeficiency Virus Serological Markers in Samples Collected as HemaSpot and Whatman 903 Dried Blood Spots

Dried blood spots (DBS) are frequently used in clinical testing for biosurveillance, infectious disease and confirmatory testing, and clinical trials, particularly for populations in remote areas. The HemaSpot-HF blood collection device (HS) provides an alternative format to the Whatman 903 cards (903) to simplify sample collection and processing. In this study, the performance of the HS was compared to that of the 903 using previously characterized clinical specimens and HIV seroconversion panels known to exhibit markers of early human immunodeficiency virus (HIV) infection. HS and 903 samples were prepared and tested by Bio-Rad GS HIV Combo Ag/Ab enzyme immunoassay (EIA), GS HIV-1/-2 Plus O EIA, GS HIV-1 Western blot, and HIV-1 Geenius assays. Both HS and 903 performed well for up to 6 months at room temperature, but a marked loss of Western blot and low titer antibody signals from early infection samples was observed in samples stored for 180 days at elevated (37 to 45°C) temperatures and high humidity (95%). HemaSpot samples placed in sealed bags with additional desiccant were protected from degradation and showed improved signal recovery relative to that of the 903. HS was easier to use than the 903 and showed higher sensitivity and reproducibility for early infection samples and improved stability.

Late ELISA Testing in Infants Born to HIV-Positive Mothers

We present the case of a young boy who was born to a human immunodeficiency virus (HIV)-positive mother and originally found to be uninfected. Evidence-based guidelines were followed regarding the mother's prenatal and infant's postnatal care, including the avoidance of breast milk. HIV DNA polymerase chain reaction qualitative tests were obtained at birth, 6 weeks and 4 months, and were all negative. He also received 6 weeks of prophylactic zidovudine. Despite these measures, his health began to decline at 17 months of age and antibody and serology tests performed at this time confirmed HIV infection. Guidelines no longer recommend routine antibody testing at 18 months of age to confirm the absence of infection in exposed infants with a record of negative virology in the first year of life. Based on this case and others we propose that this test be added back to the national guidelines for the early detection and prompt treatment of HIV infection in infants born to HIV-positive mothers.