A 13th patient has died from an outbreak of the invasive Group A Streptococcus (iGAS) bacterium in Essex.
Mid Essex Clinical Commissioning Group (CCG) said two cases found in the West Essex CCG area had been linked to the outbreak.
One of the newly discovered patients has died, it said.
The infection was discovered in Braintree and cases have been found in Chelmsford and Maldon.
Those affected were older people and the majority were receiving treatment for wounds, some in care homes but most in their own homes.
There have been 31 confirmed cases including the 13 fatalities, and another four probable cases.
Mid Essex CCG said an incident management team was working closely with West Essex CCG to manage the outbreak.
It added Public Health England (PHE) would be advising what control measures needed to be implemented.
Previously the CCG said it had put in place measures including a programme of preventative antibiotics for community nursing staff and a deep clean of all community nurse bases.
PHE East said it was carrying out a full investigation.