Expert warns of tougher fight vs infectious diseases amid climate change

BANGKOK, Thailand — Infectious diseases may become harder to contain as the global climate continues to change, according to Subramanian Swaminathan, president of the Clinical Infectious Diseases Society (CIDS) of India.

Speaking at the Asia-Pacific International Roche Infectious Diseases Symposium (APAC-IRIDS) in Bangkok on Wednesday, Swaminathan said climate change-driven population displacement is among the factors contributing to the challenge.

“When you have that, resource mobilization can be a problem. Therefore, pathogen (biological agents like bacteria, viruses, fungi and parasites that cause diseases) transmission will be even higher,” he explained.

Article continues after this advertisement

Around 250 million people were internally displaced from their homes due to weather-related disasters over the past 10 years, according to a November 2025 report by the United Nations (UN) High Commissioner for Refugees.

FEATURED STORIES

GLOBALNATION

GLOBALNATION

GLOBALNATION

Swaminathan also cited climate-change-driven food insecurity as a factor that makes it more difficult to combat infectious diseases.

“When nutrition is compromised, obviously, our ability to fight infections is also poorer,” he said.

A UN World Food Program fact sheet in September 2021 estimated that hunger and malnutrition rates could rise by 20 percent by 2050 if climate change’s adverse effects are not prevented or mitigated.

READ: AMR: When infections fight back, kill

Article continues after this advertisement

Change in pathogens

The CIDS India chief also said climate change was affecting pathogens themselves.

According to Swaminathan, a 1-degree Celsius increase in local temperature could lead to a 5 to 10 percent rise in cases of diseases caused by Salmonella bacteria.

Article continues after this advertisement

Salmonella is commonly transmitted through contaminated water or undercooked food and can cause intestinal infections, among other illnesses.

Swaminathan added that warmer conditions brought about by climate change could also make pathogens harder to treat with antibiotics, contributing to a phenomenon known as antimicrobial resistance (AMR).

He explained that, if an area’s local temperature rose by 10 degrees Celsius, the bacteria Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae would become more drug-resistant by 4.2 percent; 2.7 percent; and 2.2 percent, respectively.

“There is a dire correlation between temperature rise and drug resistance,” he added.

Swaminathan was citing a 2018 study by researchers at Harvard University and the Boston Children’s Hospital in the United States, and the University of Toronto in Canada.

He also said climate change-driven droughts were even affecting microbes in the soil.

“The normal soil has antimicrobial elements already. This is usually diluted because of water. The soil is moist and, therefore, the concentration (of antimicrobial elements) is very low,” Swaminatahan detailed.

“When the soil dries up, these antimicrobial compounds get concentrated and, therefore, pathogens have to evolve mechanisms to survive drying. And what do you have? Higher chance of drug-resistant infections,” he added.

Citing a 10-year study by Chinese and American scholars published last April, Swaminathan said grassland soil showed a 24 percent increase in antimicrobial resistance genes due to long-term warming.

READ: COVID-19, hantavirus, and disease X: Preparing for the next epidemic

Need for climate-resilient systems

“We have to build up climate-resilient systems,” Swaminathan said.

“For most of us clinicians, we start when the patient comes to the hospital. But, how many of us actually go into the community to see what’s happening?” he added.

He explained that, foremost, authorities must address the misuse of antibiotics, which he noted is weakening the drugs’ effectiveness.

“We have to use antimicrobials sensibly and have to raise public awareness,” Swaminathan said.

He then added that, although vaccination against infectious diseases is important, adequately managing the environment is likewise vital.

“The most effective intervention in public health is actually sanitation, water supply and sewage disposal [management],” the CIDS India chief stressed.

He further said public health systems must also improve their diagnostic testing.

“We need to have smarter user diagnostics so that we can use the resources that we have currently as smartly as possible so that we can have less collateral damage,” he added.

Lastly, Swaminathan also cited the “One Health” approach, which the World Health Organization defines as a “unifying approach that aims to sustainably balance and optimize the health of people, animals and ecosystems.”

“We need to have a willingness for countries to work together on this program. And it has to be done on a multilateral framework,” he said.

Your subscription could not be saved. Please try again.

Your subscription has been successful.

“One country alone cannot fix this. It has to be everybody working together. And we need a global plan,” he added. /dl