Postnatal transmission of human immunodeficiency virus type 1 from mother to infant. A prospective cohort study in Kigali, Rwanda.
BACKGROUND
Although transmission of human immunodeficiency virus type 1 (HIV-1) from mother to infant has been well documented during pregnancy and delivery, little is known about the possible transmission of HIV-1 during the postnatal period.


METHODS
We conducted a prospective cohort study in Kigali, Rwanda, of 212 mother-infant pairs who were seronegative for HIV-1 at delivery. All the infants were breast-fed. The subjects were followed at three-month intervals, with Western blot assays for antibodies to HIV-1 and testing of mononuclear cells by a double polymerase chain reaction (PCR) using three sets of primers. To evaluate potential risk factors, each mother who seroconverted was matched with three seronegative control women.


RESULTS
After a mean follow-up of 16.6 months, 16 of the 212 mothers became seropositive for HIV-1. Of their 16 infants, 9 became seropositive. One infant was excluded from the analysis because of a positive test by PCR on the blood sample obtained at birth. Postnatal seroconversion to HIV-1 occurred in four of the five infants born to the mothers who seroconverted during the first 3 months post partum, and in four infants of the 10 mothers who seroconverted between month 4 and month 21. In all cases, the infant seroconverted during the same three-month period as the mother. The main risk factor for maternal seroconversion was being single.


CONCLUSIONS
HIV-1 infection can be transmitted from mothers to infants during the postnatal period. Colostrum and breast milk may be efficient routes for the transmission of HIV-1 from recently infected mothers to their infants.
Van de Perre
P
P
AIDS Reference Laboratory, National AIDS Control Program, Kigali, Rwanda.
Simonon
A
A
Msellati
P
P
Hitimana
D G
DG
Vaira
D
D
Bazubagira
A
A
Van Goethem
C
C
Stevens
A M
AM
Karita
E
E
Sondag-Thull
D
D
D001483:Base Sequence; D015331:Cohort Studies; D003126:Colostrum / Q000382:microbiology; D005260:Female; D015658:HIV Infections / Q000635:transmission*; D006679:HIV Seropositivity / Q000635:transmission; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008393:Marriage; D008895:Milk, Human / Q000382:microbiology; D008969:Molecular Sequence Data; D009035:Mothers; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011446:Prospective Studies; D012307:Risk Factors; D012432:Rwanda