Whole genome sequencing of multi-drug resistant Mycobacterium abscessus isolates has shown the organism is spreading worldwide in the cystic fibrosis community possibly via cross-infection.
The similarity between over 1,000 isolates from patients at cystic fibrosis (CF) clinics in Europe, the US and Australia, suggests infections may be transmitted person-to-person as well as acquired from the natural environment.
The findings, published in the journal Science, support earlier evidence that similar strains of M. abscessus were found in patients attending specialist CF clinics in the UK and the US.
Professor Scott Bell, lead researcher in lung bacteria at QIMR Berghofer Medical Research Institute, said the study highlights the need for robust infection control, patient segregation and adherence to screening guidelines.
“We now have more adults than children with cystic fibrosis and to some extent adult CF clinics are bursting at the seams. Trying to manage this increased burden of disease in hospitals means enhanced cleaning protocols are very important.”
International guidelines for the management of non-tuberculous mycobacteria in cystic fibrosis recommend annual screening for patients at risk, he said.
Professor Bell also told the limbic that not everyone whose cultures return M. abscessus would develop an ongoing infection.
“About a third of patients will have a transient infection, a third will have persistent infection with no real harm and a third will develop an infection that becomes problematic requiring lengthy, complex and toxic treatment,” he said.
Cough aerosol studies conducted in Queensland have demonstrated that person-to-person transmission of M. abscessus is possible in principle but Professor Bell stressed that the primary mechanism of transmission was still not clear.
“Importantly, we haven’t yet proven whether the organism is spread via families, health professionals or medical equipment.”
However there has been concern in some centres that patients infected with M. abscessus should not be considered for lung transplants.
Professor Bell’s team is leading a national study of M. abscessus in CF. He said more research was required but M. abscessus could also be a risk to patients with other lung diseases including bronchiectasis and COPD.