For years now researchers have tried to determine the activity of HIV by measuring how much of the virus appears in blood samples – but this doesn’t account for the ability of the disease to hide in body tissue. Using math, researchers have developed a way to examine the true level of the virus’s reproduction.

Antiretroviral drugs will suppress HIV reproduction to such a degree that blood markers may disappear completely – but that doesn’t mean the virus has stopped progressing. It just means the replication process is no longer continuing in the blood. What about lymph nodes and other common hiding places for HIV?

Researchers have never bothered to check this before – it was always assumed that blood samples were a good indicator of what was going on throughout the entire body. New research using mathematical models is now digging deeper to uncover the true state of the disease.

The study involved testing individuals who were taking a mix of three HIV drugs for a period of at least two years – a fourth drug was then added to the mix. In all cases it appeared that the drugs were successfully stopping the spread of the disease. Blood replication was seemingly non-existent. The study did however reveal that progress of the disease continued unabated in other parts of the body despite what the blood was indicating.

In fact, the disease was still ravaging between one and 100 million healthy cells per day. The virus only slowed in replication because it was running out of cells to infect. The replication measurements of three out of the 10 patients involved in the study revealed that there had to be another point in the body at which replication continued with no inhibitions.

It’s bad news for current antiretroviral therapies, which may not be as effective as once hoped – but it is hoped this research will lead to the development of more effective treatment methods.