SAN DIEGO – HIV antiretroviral resistance can affect more than 10% of pregnant women, even if they are previously treatment naive, results of a case-control study demonstrated.
“Furthermore, if there is an HIV-infected infant who received HIV prophylaxis with zidovudine and nevirapine, the infant may have developed resistance to the nonnucleoside reverse transcriptase inhibitors [NNRTIs] class of medications, and timely antiretroviral-resistant testing is an important step prior to choosing an appropriate regimen,”, said in an interview prior to an annual scientific meeting on infectious diseases.
In all, 140 infants were HIV infected, and 13 had drug-resistant mutations. Of the 606 women who had sufficient nucleic acid amplification for resistance testing, 63 (10.4%) had drug-resistant mutations against one or more classes of antiretrovirals. “These mothers may have been infected with a drug-resistant strain of HIV, which they then may have passed on to their infants,” Dr. Yeganeh said. “We also found that 3 of the 13 HIV-infected infants with drug-resistant mutations against NNRTIs were born to mothers who did not have a resistant strain of HIV. These three infants likely developed resistance because of the infant prophylaxis they received with nevirapine.”
Univariate and multivariate analyses revealed that drug-resistant mutation in mothers was not associated with increased risk of HIV mother-to-child transmission (adjusted odds ratio, 0.79). The only predictors of mother-to-child transmission were log HIV viral load (OR, 1.4) and infant prophylaxis arm with a two-drug regimen (OR, 1.6). In addition, the presence of drug-resistant mutations in mothers who transmitted was strongly associated with presence of drug-resistant mutations in infants (P less than .001).
A key limitation of the trial, Dr. Yeganeh said, was that it was completed in 2011. “Antiretroviral-resistant HIV may be even more common now that antiretrovirals are more available,” she said at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society. She reported having no financial disclosures.