BALTIMORE — Fewer Americans than previously thought are controlling their HIV infections and potentially putting the public at higher risk, according to a new study from Johns Hopkins University and University of Pennsylvania.
The researchers found that there are tens of thousands of people — particularly young adults, blacks, injection drug users and the uninsured — that are not consistently suppressing their viral loads. Mostly, they are not adhering to their drug regimens.
And when patients go on and off their medications, they can become resistant to therapy and put other people in greater danger of contracting the virus that causes AIDS.
“The drugs do work and are good at suppressing the virus,” said Kelly Gebo, senior study investigator and infectious disease specialist at Johns Hopkins University. “What was surprising was at any one point in time people were doing well, but they weren’t staying suppressed.”
The researchers found that past studies were mostly only measuring one blood test. They looked at 100,000 tests from more than 30,000 patients over a decade in what’s believed to be the longest such review. They found 72 percent were tightly controlling their viral loads, which was lower than the 87 percent found in past research.
Still, the numbers were up significantly from 2001, when only about 45 percent were tightly controlling their viral loads, noted Gebo, an associate professor in Hopkins’ School of Medicine and the Bloomberg School of Public Health.
That’s probably because many people can now take one daily, multi-drug pill. But when the patients become resistant to one drug in the mix they must take different medications in multiple pills. That can increase the odds of more slip ups, the researchers said.
They also can pass on a resistant strain of HIV, they said.
More needs to be done to ensure that those infected are taking their medications and being properly advised by their doctors, said Gebo and Baligh Yehia, a postdoctoral fellow in Pennsylvania’s School of Medicine who trained as a medical resident at Johns Hopkins. They plan some more research on that front.
There are almost 1.2 million people infected with HIV in the United States. About 426,000 take antiretroviral drugs and are in routine medical care. The virus is considered suppressed when there are 400 or fewer viral copies per milliliter of blood.
“An individual who misses one day’s worth of drugs is at risk of becoming resistant,” Yehia said. “When you consider that over a large population, that’s how people spread the virus. … And they may be spreading the resistant kind. It’s a dangerous spiral.”
The researchers said they couldn’t say for sure why some populations were worse at suppressing their loads, but suspected adherence problems. Other reasons would be side effects or drug interactions.
Adherence was cited recently by infectious disease experts as the reason why a drug recently approved by the Food and Drug Administration for prevention of HIV may not be widely prescribed, in addition to its cost. This study may add some fuel to that argument, the researcher said.
“People who have the disease know they need to take the drugs and don’t,” Gebo said. “If you’re trying to prevent HIV, that’s a whole other ball of wax.”
Added Yehia: “We’ve made progress, but being able to take a pill every day is a lot harder than previously thought.”