Abstract: Currently, the majority of HIV-infected infants are found
within limited-resource settings, where inadequate screening for HIV
due to the lack of access to simple and affordable point-of-care tests
impedes implementation of antiretroviral therapy. Here we report
development of a low-cost dipstick p24 antigen assay using a visual
readout format that can facilitate the diagnosis of HIV for infants in
resource-poor conditions. A heat shock methodology was developed
to optimize disruption of immune complexes present in the plasma
of infected infants. The analytical sensitivity of the assay using
recombinant p24 antigen is 50 pg/mL (2 pM) with whole virus
detection as low as 42.5k RNA copies per milliliter plasma. In a
blinded study comprising 51 archived infant samples from the
Women and Infants Transmission Study, our assay demonstrated an
overall sensitivity and specificity of 90% and 100%, respectively. In
field evaluations of 389 fresh samples from South African infants,
a sensitivity of 95% and specificity of 99% was achieved. The assay is
simple to perform, requires minimal plasma volume (25 mL), and
yields a result in less than 40 minutes making it ideal for
implementation in resource-limited settings.