Prevention of mother-to-child transmission, drug resistance, and implications for response to therapy.
OBJECTIVE
HIV-1 drug resistance can emerge in both maternal and infant virus after exposure to antiretroviral drugs for the prevention of mother-to-child transmission of HIV. The purpose of this review is to discuss the prevalence and clinical implications (for antiretroviral treatment outcomes) of this drug resistance, focusing on more recent information.


RESULTS
New, highly sensitive laboratory assays have been developed that demonstrate even greater than previously known levels of drug resistance in minor HIV-1 variants after the use of single-dose nevirapine. At the same time, new data related to virological and immunological outcomes among women and infants after exposure to short-course prevention of mother-to-child transmission regimens suggest that although the response to nevirapine-based antiretroviral therapy after single-dose nevirapine may be compromised, this is less of a problem among women starting antiretroviral therapy more remotely from nevirapine exposure.


CONCLUSIONS
Whereas single-dose nevirapine alone should be reserved for settings in which other combination antiretroviral interventions are not feasible for the prevention of mother-to-child transmission, recent data provide measured reassurance to women regarding their future response to nevirapine-containing antiretroviral therapy.
Harvard Medical School, Brigham and Women's Hospital, Harvard School of Public Health, Boston, Massachusetts, USA.
Shahin
S
Lockman