Superbugs plus climate change equals double trouble. Here’s why
What once was a medical miracle has become a nightmare.
At a Bhekisisa webinar, scientists discussed how changing climate conditions are helping the spread of germs, called bacteria, that antibiotics, which one of the experts at the online event called “the eureka of medicine”, can no longer kill.
They’re called superbugs, because they’re near impossible to kill with the medicines we’ve relied on for decades.
It’s a big problem. A study published in The Lancet found that in 2019, such drug-resistant infections killed 1.27-million people worldwide. In roughly the same period, global HIV-related deaths were estimated at around 718 000 a year. In other words, infections caused by bacterial superbugs led to nearly twice as many deaths around the world as HIV.
The germs are all around us, says Luther King Abia, an environmental microbiologist at the University of KwaZulu-Natal, during the webinar. They can cause untreatable or difficult-to-treat throat, ear, chest (for instance, pneumonia and TB) and skin infections, as well as meningitis and cholera, and sexually transmitted infections such as gonorrhoea, syphilis and chlamydia, among other diseases.
Climate change is making the problem worse.
Why?
Changing weather patterns and more frequent and severe flooding as a result of it can make superbugs spread faster and further. We answer 11 questions, to make it easy to understand why.
- What are superbugs?
The term “superbugs” is often used to talk about germs like bacteria, viruses or fungi that can withstand drugs designed to kill or stop them from growing. They cause infections that are almost impossible to cure with the medicine we have available. “These germs have become super powerful, because nothing can kill them,” says King.
- Where do superbugs come from?
Like all living things, disease-causing bacteria try to protect themselves or fight back against threats such as antimicrobial drugs. (Bacteria and other germs are called microbes because they are so small that they can only be seen with a microscope or other imaging equipment; antimicrobial means something that works against microbes.)
Over time, some bacteria have changed in ways that let them outsmart the medicines designed to kill them. Instead of dying out, they multiply. When this happens antimicrobial resistance (AMR) is said to have developed, which gives rise to superbugs.
- What causes antimicrobial resistance?
AMR is mostly because of the overuse of antibiotics, a group of antimicrobial drugs used to treat bacterial infections. The medicines became widely used in the mid-1940s when scientists figured out how to make lots of an antibiotic called penicillin in labs. The discovery changed modern medicine because this antibiotic could kill many types of bacteria that used to cause deadly infections.
The more we use antibiotics, the more chances we give bacteria to find ways to outsmart the medicine.
Bacteria replicate by dividing in two, which means every time a bacterial cell divides, their number doubles. Because their life cycle is so fast, the doubling effect quickly leads to huge numbers of germs developing. If even just a few are able to withstand the antibiotic’s effect and so survive until the next replication cycle, the number of resistant ones can increase very fast.
The more a certain type of germ gets peppered with a specific antibiotic, the bigger the pool of those that aren’t affected by the drugs become, until, eventually, each new copy of that type of germ is able to withstand the medicine.
- What does the data say about superbug infections?
”Antimicrobial resistance […] is without question one of the most pressing health challenges of our time,” Tedros Ghebreyesus, the World Health Organisation (WHO) director general, told world leaders in 2024.
Data from the WHO’s latest AMR report, published in October, together with a useful fact sheet, shows that nearly one in six bacterial infections worldwide is resistant to commonly used antibiotics. In Africa, it’s one in five.
It’s a growing problem. Several common bacteria are showing resistance to widely used antibiotics, especially in poorer parts of the world. In fact, “by 2050, drug-resistant infections could have killed 39.1 million people [since 2025] — that’s about eight jumbo jets crashing every single day for 25 years,” says King. The figure refers to deaths where drug-resistant infections become untreatable or turn routine care into a serious risk, according to a 2021 study published in The Lancet.
The bacteria that are fast becoming resistant include Escherichia coli, a germ that often causes urinary infections, Klebsiella pneumoniae, a germ that can cause serious pneumonia and infections in newborns and hospital patients, and Acinetobacter baumannii, a type of microbe often found in hospitals, infecting the lungs and making wounds difficult to heal.
Poorer countries are often hard hit by superbug infections. But a report from the WHO and UN Environment Programme shows that many of the countries don’t have lab facilities to test what type of germs causes an infection. Without such tests, doctors often have to guess which type of antibiotic will work. If the guess is wrong, the treatment won’t kill the infection and the WHO warns that any resistant germs present can then keep multiplying. Too few equipped labs therefore make it easier for drug-resistant infections to spread.
- Why does climate change make superbugs spread?
Changes in weather patterns and more frequent floods, heavy storms, heatwaves or droughts are signs of climate change. The fallout of the changes can weaken sanitation systems, whether because of infrastructure being damaged or clean, running water being scarce, which can cause infections to spread easily. Floods and storms can carry germs from one area to another, making the infections that follow harder to stop.
Some disease-causing microbes in a certain area might be resistant to medicine, and can spread to more people and places when floods or heavy rain carry dirty water, sewage and mud further and faster than usual. For instance, a study that looked at antibiotic resistance before and after floods found that floodwaters can carry many, many superbugs into rivers, soils and coastal waters, making it more likely that people come into contact with them.
Droughts too can help germs, including superbugs, spread. When water supplies run low, people struggle to wash their hands or flush toilets properly, which makes it easier for germs to move between people. Because climate change is causing longer periods of drought, these conditions are likely to become more common, increasing the risk that superbugs spread in communities.
- How does hotter weather affect superbugs?
Heat helps bacteria grow and adapt faster. For example, a 2025 study found that when soil warms (because of hotter days), bacteria can switch on more genes that can help them withstand drugs. In this way, higher temperatures can help superbugs survive and multiply. An analysis published last year showed that hotter weather and heatwaves are linked to more drug-resistant infections around the world.
- How do superbugs affect people’s lives?
Drug-resistant germs make common illnesses or injuries, like urinary tract infections, pneumonia, wounds and blood infections, more dangerous. When antibiotics that used to be effective don’t work anymore, infections last longer, are harder to control and have more time to spread — and doctors have fewer safe treatment options.
This is also bad news for everyday medical procedures like childbirth, surgery and cancer treatment, when antibiotics are important to help stop infections when the body’s immune system is weak. Without effective antibiotics, problems that were once easy to treat can quickly become serious.
According to the South African health department’s latest strategy framework for AMR, patients with superbug infections often have to stay in hospital longer and they have more complications. This is a serious warning, says King. If the trend continues, more people will die from infections doctors can’t treat, hospitals won’t cope and treatment will become more expensive for both public and private patients.
- Who is most likely to get very sick from superbug infections?
AMR hits hardest among babies and older people because their immune systems are weaker. A global analysis, which looked at drug-resistant infections between 1990 and 2021, found that deaths caused by superbugs among people aged 70 and over almost doubled in this time.
Superbug infections also hit the poor hard — even in a wealthy country like America, where a study in Texas found that people living in poorer neighbourhoods were far more likely to have superbug infections than those in wealthier areas. This, the researchers said, suggests that crowding, poor sanitation and less access to healthcare create conditions that make it easier for superbugs to spread. An analysis of studies from many parts of sub‑Saharan Africa shows that in poorer communities, where water, toilets and healthcare are limited, drug-resistant infections are common.
- Is antimicrobial resistance a problem in South Africa?
Yes. The clearest example of AMR in South Africa is drug-resistant TB. When TB no longer responds to the main medicines used to treat it, it’s called multidrug-resistant TB, or MDR-TB. If the bacteria become resistant to even more drugs, including the backup ones, it’s called extensively drug-resistant TB (XDR-TB).
The WHO says many people with drug-resistant TB aren’t getting the right treatment. South Africa is one of the 10 countries where this gap is largest. TB treatment is hard enough and even though some new medicines are easier to take, the stronger drugs used for resistant TB are much tougher on patients. Treating can take years, the medicines can be toxic and the side effects are often severe. TB shows, in the most human way, what antimicrobial resistance looks like when it hits home.
- What about making new types of antibiotics to stay ahead of the germs?
It’s not that simple. Developing a new antibiotic is slow, expensive and often not profitable for drug companies. Doing this can take more than a decade and cost more than $1-billion — that’s around R16.5-billion over 10 years — and even then, bacteria often start finding ways around new medicines within a few years.
Different antibiotics work by attacking different “weak spots” in bacteria, for example, breaking down their cell walls or blocking how they make proteins. But bacteria don’t have endless weak spots and antibiotics target many of them. When new antibiotics come out, they’re often just small variations on older drugs, not truly new weapons. That means bacteria can adapt to them more quickly, especially if the drugs are overused.
We also need to protect the drugs we have by using them wisely, preventing infections in the first place, and tracking how resistance spreads.
- What does the “One Health” idea mean?
Humans, animals and the environment are connected and germs move freely between them. When resistance builds in one corner, it doesn’t stay there.
How it works in real life is that people get infections from water, food, soil, animals and other people. Animals also get infections and are often treated with antibiotics. The waste from both people and animals flows into the environment, especially into water systems, where bacteria mix, survive and sometimes become resistant. Those resistant bacteria can then move back into people through drinking water, crops or direct contact.
Climate change makes the links stronger. An analysis of data from 2000 to 2023 shows that higher temperatures and extreme heat tend to make drug resistance worse. Rainfall also affects resistance but in different ways, depending on the germ.
This shows why AMR plans need to take climate into account.
Hotter weather helps bacteria grow faster. Heavy rains and floods wash waste from farms, households and clinics into rivers and dams and can spread resistant germs over wide areas. Drought forces people and animals to share limited water sources. As weather patterns change, diseases move into new regions, taking resistance with them.
This is why we can’t fight AMR by focusing on hospitals alone. Slowing resistance also depends on safe water and sanitation, good farming practices, careful antibiotic use in people and animals and planning for climate pressures. The systems are connected, so the solutions have to be connected too.
This story was produced by the Bhekisisa Centre for Health Journalism. Sign up for the newsletter.