Severe cellulitis requiring hospital admission presents a relatively unknown burden to healthcare systems in England. For diagnoses due to group A Streptococcus (GAS), only those blood culture-positive would currently trigger public health actions to protect close contacts.
Here we describe severe cellulitis due to GAS in England, including assessment of secondary-household transmission risk.
Severe cellulitis admissions (identified by ‘cellulitis’ ICD-10 codes and overnight hospital stay) were extracted from Hospital Episode Statistics for 01/01/2015 to 30/06/2022 and linked to UKHSA’s national laboratory surveillance database, also used to identify invasive GAS (iGAS) cases. Unique Property Reference Number and property type were derived, facilitating identification of secondary-household iGAS clusters (within 90-days).
Between January-2015 and June-2022, 10,740 severe GAS cellulitis admissions were identified (2.3/100,000), comprising 1.0% of all cellulitis admissions. Cases had a median hospital stay of 5-days (IQR: 3-11 days); 1.9% of individuals (n=203) admitted multiple times. Working age individuals (16-64yrs) comprised the majority of admissions, only 12.1% being children (<18yrs).
Residence was identified for 69.3% cases; 91.3% were resident in private homes, 3.7% in care homes, and 0.9% in houses of multiple occupancy.
Eleven secondary-household iGAS cases were identified in private homes with severe cellulitis, of whom 2 died within 7-days of diagnosis, with a median time-to-onset of 7-days (IQR: 2.5-20).
Risk ratios indicate secondary-household incidence was 152.1-fold greater than the background incidence (3.17/100,000).
Our study identified the burden of severe GAS cellulitis and increased risk to household contacts. Future public health guidance should consider actions to protect close contacts.