In May, DHHS released updated guidelines for treatment of pregnant women with HIV, intended both to benefit the woman's health and to prevent transmission of HIV to the baby. The new version did not include major changes, but added a new rating system and further information about drug resistance, safe delivery methods, and treatment of HIV positive pregnant women coinfected with hepatitis B. The revised guidelines are available from AIDSinfo.
The following month, DHHS issued updated ART guidelines for children with HIV, including a stronger recommendation that all infected babies under 12 months of age should start treatment, regardless of CD4 cell count or percentage. These guidelines are available from AIDSinfo.
Revised World Health Organization (WHO) recommendations, issued last June, advise that exposed infants be tested for HIV by four to six weeks of age. All infected children under the age of two years should start antiretroviral treatment when diagnosed, again regardless of CD4 cell count or percentage or presence of clinical symptoms.
Between the ages of two and five years, HIV-infected children should initiate ART when their CD4 count falls to 750 cells/mm3 or their CD4 percentage to 25% or lower. Children age five years and older should follow the latest WHO adult recommendation to start treatment when the CD4 count falls to 350 cells/mm3.
This past fall, WHO released updated ART guidelines for pregnant women and infants who have received single-dose nevirapine (Viramune). This regimen is widely used in resource-limited settings to prevent mother-to-child HIV transmission -- especially for women who do not receive care prior to delivery -- but mothers and infants exposed to a single dose may develop drug resistance that can compromise future NNRTI therapy.
WHO therefore now recommends that women exposed to single-dose nevirapine within the past year should be treated with a combination ART regimen containing drugs other than NNRTIs, and babies should receive lopinavir/ritonavir (Kaletra).
This revision is supported by two studies published in the October 14, 2010, New England Journal of Medicine. The OCTANE A5208 trial analyzed 745 women in seven African countries who required ART for their own health.
Among women previously exposed to single-dose nevirapine, those subsequently treated with nevirapine-based combination ART were significantly more likely to experience virological failure or death than those using a lopinavir/ritonavir-based regimen. Looking only at women with identified nevirapine resistance mutations, the failure rates were 73% vs. 6%, respectively.
Nevirapine resistance and the associated risk of treatment failure diminishes over time, however, and the guidelines state that women can safely use nevirapine in a combination regimen one year after receiving a single preventive dose.
The second study, known as P1060, assessed treatment outcomes among 164 babies (up to three years of age) who were exposed to single-dose nevirapine during delivery or immediately after birth. Again, children subsequently treated with a nevirapine-based combination regimen were significantly more likely to experience virological failure or to discontinue treatment than those receiving lopinavir/ritonavir. Among babies with identified resistance mutations, the failure/discontinuation rates were 83% vs. 18%, respectively.
Study investigators concluded that alternative strategies for prevention of mother-to-child HIV transmission "are urgently required." The authors of an accompanying editorial, however, noted that single-dose nevirapine would continue to be used due to its low cost and widespread availability.
Liz Highleyman (email@example.com) is a freelance medical writer based in San Francisco.