An independent investigation is to be launched into a deadly outbreak of an infection which has claimed 13 lives.
Mid Essex Clinical Commissioning Group (CCG) has called in a team to probe the spread of the invasive Group A Streptococcus (iGAS) bacterium.
The strain has been linked to at least 31 confirmed cases, including the 13 fatalities.
The investigation will take about six months and results "will be shared and implemented," said the CCG.
It has been ordered through the NHS Serious Incident Framework.
Public Health England (PHE) is using a new tool to analyse the DNA sequence of the bacteria, allowing it to identify people affected by the same strain.
The technique has shown that a case in Basildon in 2018 and one in Southend this year are not linked to the outbreak.
The outbreak 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.
The CCG said infection prevention control measures were in place, and PHE had recommended enhanced measures including swabbing and testing of staff and patients.
PHE said most of the cases could be linked with community nursing treatment and a deep-clean of nursing bases was ordered.
The CCG said the risk of healthy people contracting iGAS was "very low", and antibiotic treatment was "very effective" if started promptly.