Multidrug-Resistant Mycobacterial Infection Spread Human-to-Human

Scientists have identified for the first time that the multidrug-resistant non-tuberculosis mycobacterium Mycobacterium abscessus was spread human-to-human among patients with cystic fibrosis during a recent outbreak. Their research, published online in The Lancet and titled Whole-genome sequencing to identify transmission of Mycobacterium abscessus between patients with cystic fibrosis: a retrospective cohort study, used whole genome sequencing to track an outbreak of the infection at a treatment center in the United Kingdom. The outbreak spread despite stringent infection-control measures.

Currently, between 3% and 10% of patients with cystic fibrosis in the United States and Europe have M abscessus infection, and the reasons for the growing rates are unclear, according to background provided in the paper. 

The researchers analyzed the DNA of 31 infected patients with cystic fibrosis from Cambridge Centre for Lung Infection at Papworth Hospital between 2007 and 2011. Findings showed that 2 clustered outbreaks were caused by genetically identical or near-identical strains of M abscessus subspecies massiliense (from 11 patients), that differed by less than 10 base pairs.

The researchers concluded that the discovery of human-to-human transmission raises several questions about infection control used in treatment centers. Chief among the concerns are the risk of cross-infection with other patient populations and other non-tuberculosis mycobacterium species.

Study abstract is available here.