First reported cluster of overwhelming group A streptococcal septicaemia and associated chickenpox infection in the UK.

We report the first reported cases of epidemiologically linked invasive group A streptococcal septicaemia, with one fatality, following primary chickenpox infection in previously fit and well children who attended the same preschool. Invasive group A streptococcal sepsis is a well documented complication of chickenpox, which requires prompt and aggressive treatment. Following the cluster, public health measures were put in place to prevent further disease. Varicella vaccination has been shown to significantly reduce hospital admissions as well as deaths related to chickenpox infection. This is the first reported cluster of two epidemiologically linked patients in the UK.