Researchers discover new method of determining when patients contracted HIV

Since the virus may lay dormant for months or years, it can be difficult to clinically determine how long an HIV-positive individual has been infected. However, Swiss scientists said they have discovered a novel way to estimate when the virus was contracted.

In a study published in the journal Clinical Infectious Diseases, researchers reported that drug resistance and viral variety in the blood may be the answer.

When a person first contracts HIV, he or she is typically infected with one or a few strains. As the virus multiplies, it acquires mutations that create multiple strains.

The team said that over time, these strains become more and more diverse, and many of them develop a resistance to antiviral medications.

While clinical tests used to be clouded by this diversity, the researchers assumed that greater heterogeneity and resistance indicated greater time since infection.

They concluded that some simple blood tests can tell medical specialists if an HIV infection is more than a year old, adding that further advances may result in greater accuracy.

Individuals who believe that they have contracted HIV or another sexually transmitted disease may consider using online testing services as soon as possible.