INFECTIOUS DISEASE

Filed Under News 

Adding Nevirapine to HIV Regimen Halves Newborn Transmission Rate

 

 

Newborns are most susceptible to HIV in the two weeks following birth.

 

According to an article published in the New England Journal of Medicine (2012;366:2368-2379), adding the drug nevirapine to the regimen given to newborns of women diagnosed with HIV shortly before or during labor halves the newborns’ risk of contracting the virus. The study found that the rate of mother-to-child HIV transmission around the time of delivery was 2.2% among infants who received the standard drug zidovudine combined with nevirapine, compared with 4.8% among infants treated with zidovudine alone. The study also found a reduced rate of transmission (2.4%) among infants treated with a three-drug combination: zidovudine, nelfinavir and lamivudine. However, infants given the two-drug combination were less likely to have neutropenia than were those on the three drug regimen. (Neutropenia is a blood disorder consisting of low levels of neutrophils, a type of infection fighting white blood cell.) The two drug combination is also less expensive and easier to administer than the three drug combination.

 

The study included more than 1,600 infants born between 2004 and 2010. All had received one of three treatments:

 

— the standard twice daily zidovudine alone for six weeks,

— twice daily zidovudine for six weeks plus three doses of nevirapine in the first six days after birth

— twice daily zidovudine for six weeks plus two weeks of treatment with nelfinavir and lamivudine.

 

To reduce the risk of HIV transmission through breast milk, mothers were counseled to formula feed their infants.

 

Within 48 hours after birth, all infants were tested for HIV. Results showed that about 6% tested positive, indicating that infection occurred before birth. At three months, about 8% of all the infants were HIV positive. The authors then calculated the overall infection rates for all the infants in the study – those infected at birth, and later, after 6 weeks of treatment. In addition to acquiring HIV during their time in the womb, infants may also become infected during the labor and delivery process. The study evaluated the effectiveness of the treatments in reducing HIV transmission during this latter interval (intrapartum transmission). So the authors calculated the transmission rate around the time of delivery – that is, the proportion of infections among infants who tested negative at birth, but later tested positive after six weeks of treatment. In the different drug treatment groups, infection rates were 7.1% in the zidovudine-nevirapine group (which had a 2.2% transmission rate), 7.4% in the three-drug arm (which had a 2.4% transmission rate), and 11% in the zidovudine-only group (which had a 4.8% transmission rate).

 

The study also found that mothers with more severe HIV infections were more likely to transmit HIV to their infants than were other mothers in the study. Illegal drug use during pregnancy also increased the transmission rate.

 

According to the authors, the two-drug combination is relatively easy to administer and well tolerated by the babies, and now that this alternative has been shown to be effective, it is increasingly being adopted worldwide to prevent transmission in these high-risk situations.

Comments

Leave a Reply

You must be logged in to post a comment.