Mother-to-child transmission of HIV is an important factor in the AIDS pandemic, although important strides have been made in limiting transmission with antiviral drug therapies before, during, and following birth. In the last few decades the rate of mother-to-child transmission of HIV in the United States has been reduced from 25 percent to its current rate of less than 2 percent. However, the transmission of drug-resistant strains of HIV from mother to child is still a problem, and much is unknown concerning how such transmission affects the responses of infants to various drug treatments.
The study, conducted by Deborah Persaud, MD, of Johns Hopkins University School of Medicine and colleagues working throughout the United States, analyzed HIV-infected infants less than six months of age enrolled in a large, multi-center clinical trial covering 10 states.
Their results showed that five of 21 HIV-positive infants were infected with drug-resistant HIV transmitted from their mothers—a surprisingly high figure. Of those five, four were resistant to non-nucleoside reverse transcriptase inhibitors (NNRTIs), a common class of antiretroviral drug used to treat HIV infection and to prevent mother-to-child transmission. All had uncommon drug-resistance mutations that some resistance tests would miss.
Earlier studies looking at infants treated with antiretrovirals in an unsuccessful attempt to prevent mother-to-child transmission found the virus quickly developed resistance, but levels of resistant virus declined over time to undetectable levels. In the current study, however, researchers found these resistant viruses quickly
Source:Infectious Diseases Society of America