James Cook University researchers are warning microorganisms previously thought to be benign are becoming more dangerous worldwide – and especially in the tropics.
Professor John Miles from JCU's Australian Institute of Tropical Health and Medicine said diseases caused by non-tuberculous mycobacteria (NTM) have been steadily increasing globally.
"NTMs are the lesser-known cousins of tuberculosis. They are tiny bacteria that live in the soil, water systems and on common household items. We used to think they were harmless, or at least only dangerous to people with lung problems or who were immunosuppressed, but we're finding that's changing," said Professor Miles.
He said NTMs are now infecting the lungs of seemingly healthy people.
"They are highly multidrug resistant and are killing people. For reasons we do not understand and are only beginning to investigate, NTM lung infection rates have doubled over the last 10 years," said Professor Miles.
He said with the rise in the number of global infections NTMs are being recognised as an emerging threat causing significant morbidity and mortality.
"NTMs can withstand a wide range of temperatures and are disinfectant resistant. As they are more prevalent in the tropics, it's important to note that 40% of the world's population live there and due to climate change, the tropics are expanding – which will increase NTM infection regions," said Professor Miles.
Professor Scott Bell, the papers' co-author, said NTM infection is also a growing concern for people with cystic fibrosis.
"Questions range from how did I get it to should I get treated and what is the best treatment available? Alarmingly, NTM has also recently been found to spread person-to-person," he said.
Dr Champa Ratnatunga, the paper's first author, said scientists need to work on better and faster ways to diagnose and treat these infections.
"NTM lung infections are a concerning problem as they are increasing in prevalence in both the developed and the developing worlds," she said.
