A rare strain of a strep superbug that caused an epidemic in Canada a decade ago has been identified by scientists in Arizona’s Coconino County. The Transitional Genomics Research Institute (TGen) announced the findings in a study at the end of March.

Identified as a rare form of Group A Streptococcus, which typically causes strep throat, the emm59 strain of this bacteria can also cause severe skin infections. One of the more concerning aspects of the bacteria is that it can lead to necrotizing fasciitis, a flesh-eating bacteria that can result in amputation or death.

The emm59 strain is believed to be an evolved version of the same strep bacteria that spread across Canada more than a decade ago and infected at least 300 people. Approximately one-third of the infections became severe and resulted in at least 10 deaths.

“When compared with all other publicly available U.S. emm59 isolate genomes, a significant number of Flagstaff cases had group A strep strains that were identical,” said Dr. David Engelthaler, TGen’s Director of Program and Operations and the lead author in the study. “This tells us that we have an outbreak of this particularly nasty superbug.”

Scientists with TGen tracked the bacteria in Flagstaff between January and July 2015, and believe it to be related to some similar cases found in New Mexico.

While the presence of emm59 does pose a public health concern, it is unlikely members of the general public may contract the bacteria. The infection is typically contracted through skin-to-skin contact and the flesh-eating bacteria occurs when the bacteria enters the body through an open wound. Most reported cases occurred among homeless populations and in jails where conditions may be less hygienic.

Other at-risk populations identified in Canadian cases included intravenous drug users, people living in unhygienic conditions, and people with chronic illness.

Dr. Engelthaler also said that “investigations are ongoing in Arizona to further determine the extent of the current strep outbreak, and to help minimize its spread, especially to at-risk populations.”