McGill study: Half of HIV spread by newly infected
Team followed patients in Montreal clinics over eight years
A new study led by McGill University researchers shows that half of all HIV transmissions happen when newly infected people don’t know they are carrying the virus and may not even test positive for it.
The study, published in the April edition of the Journal of Infectious Diseases and already available online, followed 2,500 patients in eight Montreal HIV clinics over eight years. It showed that newly infected patients are eight times more likely to transmit the virus than those in the chronic stage of AIDS given the same behaviour.
Dr. Mark Wainberg, Director of the McGill AIDS Centre and internationally respected AIDS researcher, presented the findings at an academic AIDS conference in Los Angeles March 1 with lead author Dr. Bluma Brenner of the McGill Faculty of Medicine and the Jewish General Hospital.
“The most alarming thing is the confluence of a highly infectious state and the lack of awareness of that state,” said Dr. Wainberg. “It means we have to reconsider a lot of what we’re doing, both on the public education front and on the early intervention front.”
McGill Professor of Medicine and McGill University Health Centre (MUHC) AIDS researcher Dr. Jean-Pierre Routy, who was also instrumental in the study, said the Montreal urban population provided the ideal sample for the groundbreaking survey. “We had the infrastructure and the data here to get a comprehensive picture.” The study also involved researchers at Université de Montréal and at private and public AIDS clinics in the city.
The findings could change not only how soon people get tested after engaging in high-risk behaviour, but how they view that behaviour. “It has been shown that an HIV-positive diagnosis modifies high-risk behaviour,” said Dr. Wainberg. “So the more actively we can seek out and find newly infected people for testing and counselling, the better.”