July 11, 2012
Getting the treatment-as-prevention (TasP) strategy to work as well in the real world as it has in trials may be difficult, experts suggest in a series of articles published Tuesday. Many barriers, including capacities and cost-effectiveness, could hamper the success of using antiretroviral therapy (ARVs) to stop new HIV infections, the experts wrote.
"The field is split about whether it's really the best thing and it's going to stop transmission, or if it's a small part of the puzzle," said Timothy Hallett, an epidemiologist at Imperial College London and co-author of one of the articles.
Early treatment "can have an impact, but it's not going to eradicate HIV," said David Wilson, a University of New South Wales epidemiologist whose study appears in the collection. He looked to four places where testing and treatment linkage were already emphasized: British Columbia, San Francisco, France, and Australia. In best-case Australia, treatment is freely available and about 70 percent of people with HIV are on it. Nonetheless, new HIV diagnoses there grew from 700 per year in 1999 to 1,000 annually in 2011, Wilson said.
People need to get tested regularly; start ARVs once they test HIV-positive; and adhere to ARVs for their whole lives to control the virus, said Wilson. Failure on any of these points reduces TasP's potential, he said.
However, one important implication from TasP efforts has been that treatment and prevention do not have to compete for resources, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. A critical goal now is reaching and treating those people who do not know they are infected with HIV, he said.
[PNU editor's note: To access the collection of 10 articles about TasP, published Tuesday in Public Library of Science (PLoS) Medicine, visit: www.ploscollections.org/TasP2012.]