In a sweeping revision of its guidelines for treating HIV infections, the World Health Organization said today that countries should begin drug treatment sooner, phase out the use of the antiviral drug stavudine and begin treating breastfeeding women.
The guidelines are designed to delay progression of the infection to AIDS, reduce undesirable side effects and minimize transmission of the virus.
"These new recommendations are based on the most up to date, available data," Dr. Hiroki Nakatani, the WHO's assistant director general for HIV/AIDS, TB, malaria and neglected tropical diseases, said in a statement. "Their widespread adoption will enable many more people in high-burden areas to live longer and healthier lives."
In 2006, the WHO recommended that patients begin receiving antiretroviral therapy (ART) when their CD4 counts -- a measure of immune system strength -- had fallen to 200 cells per cubic millimeter of blood. By that point, however, the first signs of AIDS, such as opportunistic infections, had begun.
Studies reported since then have clearly demonstrated that starting therapy earlier delays progression to AIDS and keeps the person healthier longer. Early treatment also reduces the level of virus in the blood, thereby reducing its transmission to others. The new guidelines now recommend that treatment begin when the patient's CD4 level falls to 350 cells per cubic millimeter, regardless of whether symptoms have occurred.
Zerit, known generically as stavudine or d4T, was one of the first drugs used to treat HIV infections and is still one of the cheapest and most widely used medications for the disease, in large part because its patent expired in 2005 and several companies began making generic versions.
In 2006, about 80% of all patients in the developing world were receiving it as part of their cocktail of ART drugs. In that year, the WHO recommended that countries start cutting back on their usage of stavudine because of side effects, which include irreversible nerve damage and a loss of fat, a process called wasting.
Today, only about half of patients receive the drug, but new data about the side effects shows that that is still way too many. The WHO recommends that, instead of stavudine, patients receive either zidovudine (AZT) or Tenofovir (TDF), which are less toxic and equally effective.
Also in 2006, the agency recommended that ART be started in pregnant women in the third trimester to prevent mother-to-child transmission of the virus. At that time, the agency said, there was little evidence to suggest whether it was beneficial to continue treatment after birth while the mother was breastfeeding. However, in light of new findings, the WHO now recommends that ART be started in the 14th week of pregnancy and that it be continued until the mother stops breastfeeding.
"We are sending a clear message that breastfeeding is a good option for every baby, even those with HIV-positive mothers, when they have access" to ART, said Daisy Mafubelu, the WHO's assistant director-general for family and community health. If the new guidelines are implemented, the risk of transmission of the virus to infants could be reduced below 5%, she said.
An estimated 33.4 million people worldwide, two-thirds of them in sub-Saharan Africa, are HIV-positive. About 2.7 million people are newly infected each year.
-- Thomas H. Maugh II