The study, which is published in the Archives of Disease in Childhood, involved a review of the prenatal test histories for 25 infants diagnosed with HIV infection at a referral hospital in London from 2001 to 2005. The study focused on 21 of the cases in which prenatal care had been provided in the UK.
Twelve of the mothers had not been tested for HIV infection during pregnancy, Dr. Hermione Lyall, from St. Mary's NHS Trust in London, and colleagues report.
Of the remaining nine, four tested positive, but five did not, suggesting that although they may have been infected with HIV at the time of testing, they had not yet developed the anti-HIV antibodies which are measured in standard tests.
Infants whose mothers were not diagnosed with HIV infection fared worse than other infants. Infected infants typically had severe infections, which proved fatal in six cases.
The important message is that a negative prenatal HIV test in the mother does not mean an infant is not infected with HIV and this possibility should be considered for any child with symptoms of immunodeficiency, the investigators emphasise.