A new Ugandan study, published online in the Journal of Infectious Diseases, suggests that HIV super-infection may occur as often as initial HIV infection in the general population.
Since researchers demonstrated more than a decade ago that a person infected with HIV could subsequently acquire a second, new strain of HIV, there has been little agreement in the scientific community as to how often HIV super-infection occurs.
Previous studies have found HIV super-infection to be relatively frequent among individuals, who engaged in high-risk behaviours, but the rate of super-infection in general populations remained unclear.
Also, in a critical step that may lead to more effective HIV treatments, Harvard scientists have found pre-existing mutations in a small number of HIV patients. These mutations can cause the virus to develop resistance to the drugs used to slow its progression.
The finding is particularly important because, while researchers have long known HIV can develop resistance to some drugs, it was not understood whether the virus relied on pre-existing mutations to develop resistance, or if it waits for those mutations to occur. By shedding new light on how resistance evolves, the study, reported in online journal PLoS Computational Biology opens the door to the development of new, more effective treatments.
The data was collected from 26 clinical trials. Patients were treated with a typical combination of Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTI) drugs, which helps block the virus from multiplying. It was found that the virus is more likely to develop resistance shortly after the start of treatment or when treatment is restarted following an interruption of a week or more. However, it is less likely to develop resistance later on and when patients do not interrupt treatment.
This finding suggests that pre-existing mutations are behind the virus’ drug resistance, and that resistance, which develops early in treatment is likely the result of pre-existing mutations. Resistance that develops later is tied to mutations in the virus that occur after treatment began.
While the study holds out hope for the future development of more effective HIV treatments, the researchers emphasised that data used in the study came from trials, which exclusively included patients receiving NNRTI or un-boosted protease inhibitor treatments. It is unclear whether the results can be generalised to other treatments and to patients, who are not enrolled in clinical trials.
Meanwhile, the new study on HIV super-infection, supported in part by the United States National Institute of Allergy and Infectious Diseases (NIAID), a component of the National Institutes of Health, offers some evidence about the likelihood.
In light of the study’s findings, the authors say post-test counseling for individuals newly diagnosed with HIV infection should emphasise the risk of HIV super-infection and the possible health implications of continuing practices that put them at risk for HIV.
The blood samples examined in the study were from the ongoing NIH-supported Rakai Community Cohort Study (RCCS), a community-based open study of heterosexual men and women ages 15 to 49 years old in rural Rakai District, Uganda.
Source: The Guardian Nigeria