How HIV spreads through the brain: Simulation reveals how the virus progresses - and a nasal spray could be the most effective treatment

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Scientists are developing a nasal spray to combat HIV after discovering how the virus spreads through the brain. 

A team of Canadian researchers are working to create this new method of distributing antiretroviral therapy drugs so it can reach the brain faster.

Their new study presents the first model to predict the growth and progression of HIV, allowing researchers to see how the disease spreads through the brain.

Now they hope their findings can lead to a more effective treatment, which will decrease an active infection in the brain.

Canadian researchers created the first model to predict the growth of an HIV infection in the brain. They are developing a nasal spray that they hope will lead to a more effective treatment. pictured: HIV traveling through the bloodstream

The groundbreaking study was conducted by researchers at the University of Alberta as a joint effort between the mathematical and statistical science and neurology departments. 

The scientists created a model that can track the progression and development of an HIV infection in the brain.

Previously, experts could only study brain infection at autopsy.

The researchers now believe they can provide an estimate of how the HIV-infected brain will develop and use this information to eliminate the virus from the brain.

Weston Roda, a PhD student at the university, said: 'The nature of the HIV virus allows it to travel across the blood-brain barrier in infected macrophage - or white blood cell - as early as two weeks after infection. 

'Antiretroviral drugs, the therapy of choice for HIV, cannot enter the brain so easily. 

'The more we understand and can target treatment toward viral reservoirs, the closer we get to developing total suppression strategies for HIV infection.' 

The researchers were able to create the model after examining data from patients who died five to 15 years after they were infected.

Experts then used this data in conjunction with the known biological processes of HIV.

Roda added: 'Our next steps are to understand other viral reservoirs, like the gut, and develop models similar to this one, as well as understand latently infected cell populations in the brain.

'With the antiretroviral therapy, infected cells can go into a latent stage. The idea is to determine the size of the latently infected population so that clinicians can develop treatment strategies.' 

Researchers from Yale, University of California, San Francisco and North Carolina Universities previously found there was some evidence of brain damage from early HIV infection.

They stated this could worsen over time if people didn't take antiretroviral treatment but said these effects could be reversed with the medicine.

Other research suggests the virus can still affect the brain even if there was undetectable levels of HIV in the blood.

HIV treatments have advanced to the extent that a daily regimen of pills can make the virus undetectable and untransmittable.

Roughly 30 percent of America's 1.2 million people with HIV have reached an undetectable viral load.

A person with HIV becomes 'undetectable' when treatment targeting T-cells suppresses the virus to a level so low in their blood that it cannot be detected by measurements.

If a person is undetectable and stays on treatment, they cannot pass HIV on to a partner. No study has ever shown HIV transmission from someone with an undetectable viral load.

To date, an undetectable load is almost always achieved with daily doses of antiretroviral drugs.