For decades, the story of HIV has been one of remarkable scientific progress. The development of antiretroviral therapy (ART) transformed an almost certain death sentence into a manageable chronic condition. The principle of Undetectable = Untransmittable (U=U) has liberated people living with HIV, confirming that those with an undetectable viral load on treatment cannot sexually transmit the virus. Tools like HIV PrEP have given us a powerful way to prevent acquisition. It has been a story of triumph.

But a concerning new chapter is unfolding. A recent study from London has sounded an alarm that resonates globally, highlighting the growing threat of HIV drug resistance, especially among young people. This isn’t just a distant problem; it’s a warning shot for every major city, including Singapore. It forces us to ask a critical question: is the virus that we have fought so hard to control now fighting back?

What the London Study Found: A Sobering Reality

The study, published in the journal AIDS and reported by aidsmap, looked at young people (aged 16-25) diagnosed with HIV in London between 2017 and 2021. The findings were stark. Researchers discovered high levels of both transmitted and acquired drug resistance.

Let’s break down what this means:

• Transmitted Drug Resistance (TDR): This is when a person is infected with a strain of HIV that is already resistant to certain drugs. They haven’t taken any HIV treatment themselves, but the person who transmitted the virus to them had a resistant strain. The London study found that nearly one in five young people had resistance to at least one drug at the time of their diagnosis.
• Acquired Drug Resistance (ADR): This develops when a person is on treatment, but the virus in their body mutates and learns to overcome the medication. This is often linked to not taking medication consistently as prescribed.

The study revealed significant resistance to older classes of drugs, particularly NNRTIs (non-nucleoside reverse transcriptase inhibitors). More worryingly, it showed growing resistance to drugs like emtricitabine (FTC) and lamivudine (3TC). These are cornerstone drugs that form the backbone of almost all modern HIV treatment regimens and are also used in HIV PrEP.

Why This Isn’t Just a “London Problem”

In our interconnected world, viruses don’t respect borders. A drug-resistant strain of HIV that emerges in London can, and likely will, appear in other global hubs like Singapore. This study serves as a crucial early warning system. It highlights that as more people are on treatment globally (which is a good thing), the chances of resistance developing and being transmitted also increase if we are not vigilant.

The implications are serious. While modern first-line treatments, especially those using integrase inhibitors like dolutegravir, are still highly effective against these resistant strains, the safety net is shrinking. Drug resistance narrows a person’s future treatment options. If their first regimen fails, they may have fewer, potentially more complex or more toxic, alternatives to switch to. This is why preventing the spread of resistance is paramount for ensuring the long-term health of people living with HIV.

The Critical Link: PrEP, Treatment, and Testing

The finding of resistance to emtricitabine is particularly relevant in the age of PrEP. HIV PrEP is highly effective, but it is not 100%. In the rare event that someone acquires HIV despite being on PrEP, or if they start PrEP without realising they have already recently acquired HIV, the virus can quickly develop resistance to the drugs in the PrEP pill.

This underscores a vital message: PrEP is not a “set it and forget it” solution. It must be part of a comprehensive sexual health strategy that includes regular HIV testing. Regular testing ensures that any new infection is caught immediately, before resistance can develop, allowing for a swift transition to a fully effective treatment regimen. Anyone experiencing potential HIV symptoms should seek testing immediately, even if they are on PrEP.

Staying Ahead: How We Can Fight HIV Drug Resistance

The London study is not a reason for panic, but it is a powerful call to action. We have the tools to combat this threat.

1. Get Tested, Know Your Status: The first and most important step. An early diagnosis allows you to start treatment with the most robust regimen available, suppressing the virus before it has a chance to mutate or be transmitted.
2. Start Smart, Treat Right: Choosing the right initial treatment is crucial. Modern guidelines, supported by bodies like the World Health Organization (WHO), favour starting with potent integrase inhibitor-based regimens. These are less susceptible to pre-existing resistance. A consultation at a specialised STD clinic is the best way to ensure you are on the optimal path.
3. Adherence is Everything: For those on treatment, taking your medication exactly as prescribed is the single most important thing you can do to prevent acquired drug resistance. Every missed dose gives the virus an opportunity to replicate and mutate.
4. Use Prevention Tools Wisely: This means using PrEP correctly with regular follow-ups and testing, and understanding that condoms remain an effective barrier against all strains of HIV and other STIs.

Frequently Asked Questions

What exactly is HIV drug resistance?

It means that a person’s strain of HIV has mutated in a way that a specific antiretroviral drug can no longer effectively suppress it. The drug stops working.

Can I get tested for drug resistance?

Yes. A genotypic resistance test is a blood test that can be done after an HIV diagnosis to check for any pre-existing (transmitted) resistance. This helps your doctor choose the most effective combination of drugs for you from the start.

Does this news mean that HIV will become untreatable?

No. This is not a return to the pre-ART era. We still have highly effective first-line drugs and other options available. However, this study is a warning that we must act now to preserve these options for the future. It makes smart, early, and consistent treatment more important than ever.

Protecting Our Future: A Shared Responsibility

The news from London is a reminder that our fight against HIV is an ongoing marathon, not a sprint. The virus is constantly evolving, and so must our strategies to control it. By embracing regular testing, adhering to the best modern treatments, and using preventative tools like PrEP and condoms wisely, we can collectively combat the threat of drug resistance.

Your health is your most important asset. Whether you have questions about your HIV treatment regimen, are considering starting HIV PrEP, or simply want to know your status, taking the next step is crucial. We encourage you to book a confidential consultation with our doctors to discuss your individual needs and stay ahead of the curve.