Researchers focused on environmental and public health are highlighting a lesser-known group of pathogens that could become an increasing global threat: free-living amoebae. In a recent perspective published in Biocontaminant, they discuss how these tiny organisms are proliferating around the world, influenced by climate change, deteriorating water infrastructure, and a lack of sufficient monitoring and detection efforts.
Amoebae, which are single-celled organisms found naturally in soil and water, are mostly harmless. However, some species can lead to severe and occasionally fatal diseases. A well-known example is Naegleria fowleri, often called the brain-eating amoeba, which can result in a rare but almost always deadly brain infection. Infection can happen when contaminated water enters the nose during activities such as swimming.
Challenges in Controlling These Amoebae
“What makes these organisms particularly perilous is their resilience to conditions that eliminate many other microbes,” explained Longfei Shu from Sun Yat-sen University. “They can endure high temperatures, potent disinfectants like chlorine, and even thrive within water distribution systems that people generally deem safe.”
The researchers also note that amoebae can serve as protective hosts for other harmful microbes. Bacteria and viruses can survive within amoebae, shielded from disinfection processes that would normally eradicate them. This so-called Trojan horse effect allows dangerous pathogens to survive and spread through drinking water systems, potentially contributing to the rise of antibiotic resistance.
With rising global temperatures, the situation is expected to worsen, as heat-loving amoebae may spread to areas where they were previously rare. Several recent outbreaks linked to recreational water exposure have already heightened public concern in various countries.
A Call for a Unified Approach
The authors call for a coordinated One Health strategy that unites public health, environmental research, and water management. They stress the importance of improved surveillance, quicker and more accurate diagnostic tools, and enhanced water treatment technologies to mitigate risks before infections occur.
“Amoebae are not just a medical issue or an environmental issue,” Shu stated. “They exist at the junction of both, and tackling them requires integrated solutions that safeguard public health right from the source.”
