Environmental and public health researchers are drawing attention to a little-known group of pathogens that may pose a rising global danger: free living amoebae. In a new perspective published in Biocontaminant, the team explains that these microscopic organisms are gaining ground worldwide, driven by climate change, deteriorating water systems, and limited monitoring and detection efforts.
Amoebae are single celled organisms that naturally occur in soil and water. Most are harmless, but certain species can cause severe and sometimes fatal disease. One of the best-known examples is Naegleria fowleri (often referred to as the brain eating amoeba), which can cause a rare but almost always deadly brain infection. Infection can occur when contaminated water enters the nose during activities like swimming.
Why These Amoebae Are So Hard to Control
“What makes these organisms particularly dangerous is their ability to survive conditions that kill many other microbes,” said corresponding author Longfei Shu of Sun Yat sen University. “They can tolerate high temperatures, strong disinfectants like chlorine, and even live inside water distribution systems that people assume are safe.”
The researchers also point out that amoebae can act as protective hosts for other disease-causing microbes. Bacteria and viruses can survive inside amoebae, shielded from disinfection processes that would normally eliminate them. This so called Trojan horse effect allows harmful pathogens to persist and spread through drinking water systems and may also play a role in the rise of antibiotic resistance.
Rising global temperatures are expected to make the problem worse by allowing heat loving amoebae to spread into regions where they were once uncommon. Several recent outbreaks linked to recreational water exposure have already increased public concern in multiple countries.
A Call for a One Health Response
The authors urge a coordinated One Health strategy that brings together public health, environmental research, and water management. They emphasize the need for better surveillance, faster and more accurate diagnostic tools, and advanced water treatment technologies to reduce risks before infections occur.
“Amoebae are not just a medical issue or an environmental issue,” Shu said. “They sit at the intersection of both, and addressing them requires integrated solutions that protect public health at its source.”
