Phil B.FontanarosaMD, Deputy EditorIndividualAuthorStephen J.LurieMD, PhD, Fishbein FellowIndividualAuthor
To the Editor: Dr Miotti and colleagues1 found a significant decrease in the risk of human
immunodeficiency virus (HIV) transmission to infants after 6 months of breastfeeding
in Malawi. However, some limitations may have weakened their conclusions.
Whereas the main inclusion criterion was a negative polymerase chain
reaction (PCR) result for HIV at 6 weeks of life, more than 25% of the children
had tested negatively earlier (lower quartile, 1.4 months). For the many cases
estimated to have occurred before 3 months of life (Figure 2, in their article),
the first negative PCR result was probably obtained very early, at a minimum
of 0.7 months, and the first positive PCR result shortly after. Even by using
dried blood spot,2 timing of acquisition
of HIV infection cannot be ascertained for these children, who were nevertheless
considered as cases of postnatal transmission in the analysis. The authors'
assumption of underestimation of postnatal transmission during the first semester
of life seems therefore unlikely.
Castetbon K, Spira R, Leroy V, Dabis F. Risk of HIV Transmission Through Breastfeeding. JAMA. 2000;283(8):999-1000. doi:10.1001/jama.283.8.999