Outbreak of group A Streptococcus emm94.0 affecting people who inject drugs in southwest England, April 2017.

We report an outbreak of invasive and noninvasive group A Streptococcus during April 2017 among people who inject drugs in southwest England. To date we have identified 14 cases linked to a specific town, all confirmed as group A Streptococcus emm94.0, a strain type not previously reported in the area. We have yet to identify a source for this ongoing outbreak. Actions described here may help reduce the burden of infection in vulnerable populations.