HAART in HIV Pregnancies Cuts Risk of CMV in Infants
By C. Vidya Shankar MD
NEW YORK (Reuters Health) Jun 28 - The benefits of highly active anti-retroviral therapy (HAART) during pregnancy go beyond a reduction in mother-child HIV transmission, a new study shows -- it also cuts babies' risk of acquiring cytomegalovirus (CMV) from their mothers during birth.
The study from Los Angeles was reported online June 6th in Clinical Infectious Diseases.
Dr. Toni Frederick, the lead author from the University of Southern California, told Reuters Health by email, "By showing higher rates of CMV-related symptomatology among the HIV-exposed but uninfected infants without maternal HAART, we show the importance of improving the mother's health, reducing viral load, and improving her CD4 count with HAART in all HIV-infected women during their pregnancy."
She and her colleagues say nearly half of infants born to CMV-positive mothers become infected. The immunosuppressive effect of coexistent HIV increases CMV shedding and increases the risk of transmission to babies.
For the study, they looked for CMV in 414 infants born to HIV-positive mothers between 1988 and 2002. From 1997 onward, such mothers routinely received HAART during pregnancy and their infants received zidovudine prophylaxis during the first six weeks of life.
They included equal numbers of children from the pre and post HAART eras and compared the burden of CMV between the groups.
Urine cultures and oral mucosa swabs showed CMV in 272 mothers (66%).
Congenital CMV infection was defined as a positive urine or oral culture within three weeks of age and perinatal/early postnatal acquired infection as a positive culture within six months of age.
Altogether, 248 newborns were tested within three weeks after birth, and 393 babies were investigated later for perinatal/postnatal infection. On average, each infant was tested three times during the course of the study.
Nine infants (3.6%) were CMV positive within three weeks of age, with two displaying typical signs of congenital infection. The congenital CMV rates were similar in both groups, the researchers found. This was in contrast to a decline in congenital CMV reported by the French Perinatal cohort study post-HAART, they point out -- with the difference perhaps due to later presentation and initiation of HAART in their study.
Overall, fifty-two infants (13.2%) were culture positive by six months of age. Perinatal/early postnatal CMV rates were significantly higher among infants born pre-HAART from 1988-1996 as compared to the 1997-2002 post- HAART period (17.9% vs 8.9%; OR 4.7).
Infants born to untreated mothers were more likely to be symptomatic (41% vs 6%, OR 10.3).
Babies' HIV infection status had no effect on risk for congenital infection, but it did appear to increase the risk for CMV positivity by six months.
In a multivariate analysis, maternal CD4 cell count <200/mm3 was linked with an eight-fold increase in perinatal/postnatal CMV (OR 8.8) in the non-HAART group.
"We suggest that the improvement in the mother's health with HAART, leads to better immunologic control during pregnancy so that the quantity of virus during the birth process is reduced thus lowering the risk of CMV transmission to the newborn," Dr. Frederick said.
She added, "In breastfeeding populations, it is also possible that HAART during pregnancy and during breastfeeding could reduce rates of postnatal CMV transmission due to breastfeeding."