USAID cuts: The effects of halting antiretroviral therapy for HIV

LONDON - U.S. President Donald Trump's foreign aid freeze could lead to more than three million HIV-related deaths, as supplies of life-saving drugs are disrupted in nations hit hardest by the virus, according to the World Health Organisation (WHO).

More than 20 million people in 55 countries were relying on U.S. funding to provide their antiretroviral therapy (ART) for HIV as of last year, U.S. government data shows.

Now, many face an uncertain future after more than 80% of USAID programmes were scrapped following a six-week review to see if they aligned with Trump's "America First" policy.

HIV services around the world have been paused - particularly in the Global South - and the United Nations AIDS agency (UNAIDS) said there were reports of panic and hoarding of medication by people living with HIV.

Here's everything you need to know about ART and what this disruption means for the spread of HIV.

What is antiretroviral treatment (ART) and how does it work?

ART - the process of taking antiretroviral medication - stops HIV from reproducing in the body after infection has occurred.

The medication allows the immune system to repair itself and prevents HIV from developing into AIDS, the most advanced stage of the infection.

HIV can adapt and become resistant to treatment, so a combination of antiretroviral drugs is commonly used, although these can be merged into a single pill.

HIV is not curable, but ART reduces the amount of virus in a person's blood until it is undetectable, making it untransmittable during sex.

This happens within six months or less of taking the medication, according to the National Institute of Allergy and Infectious Diseases. 

However, missing doses and stopping and re-starting treatment can lead to drug resistance, which can allow HIV to multiply and progress to disease, UNAIDS says.

HIV transmission has been reduced by more than 50% since 2000 because of ART, said Masen Davis, executive director of Funders Concerned About AIDS (FCAA).

"When people are on ART, they can work, care for their families and contribute to their communities. But if treatment is interrupted - even for a short time - HIV comes back," Davis told Context.

Where has ART been impacted by US foreign aid cuts?

Many countries have faced disruption to supplies of ART drugs and treatment delivery, although a limited waiver has allowed some services funded by the flagship President's Emergency Plan for AIDS Relief (PEPFAR) to resume.

Eight countries, including six in Africa, could run out of ART in the coming months, the WHO said on March 17.

These are Kenya, Nigeria, Lesotho, South Sudan, Burkina Faso, Mali, Haiti and Ukraine.

Haiti had been treating 85% of people living with HIV with ART before the cuts, UNAIDS said.

In Uganda and Ethiopia, ART-providing facilities are operating at reduced capacity while 8,493 PEPFAR-funded staff have been let go in South Africa, UNAIDS said.

In Namibia, funding for the next shipment of ART drugs needed to sustain treatment until the end of the year has not been confirmed, UNAIDS said.

Other countries around the world, including Zimbabwe, Liberia, Guatemala and Peru, have recorded disruption in ART services and HIV prevention for key populations, including gay and bisexual men, transgender people and drug users.

What have HIV and AIDS groups said?

Without access to ART, decades of progress will be destroyed, the International AIDS Society told Context, with low-income countries hardest hit.

"Treatment interruptions can lead to HIV drug resistance, making medications less effective and limiting future treatment options," the organisation said in an emailed statement.

"This would not only affect people living with HIV but also place immense strain on healthcare systems and deepen existing health inequalities."

Even if the U.S. did resume funding, it will take a long time for clinics to be restaffed and treatment to go back to how it was, Davis said.

"The consequences of this crisis will reverberate for years to come," he said.

(Reporting by Lucy Middleton; editing by Ellen Wulfhorst.)