A Cluster of Paediatric Invasive Group A Streptococcal and Chicken Pox Infections

Area of Science:

• Pediatric Infectious Diseases
• Epidemiology
• Vaccinology

Background:

• An increase in invasive group A streptococcus (GAS) cases was observed at a pediatric infectious disease department.
• This prompted a review of all invasive GAS cases within a specific timeframe and location.

Purpose of the Study:

• To review all identified cases of invasive group A streptococcus (GAS) in children during 2016.
• To analyze the clinical characteristics, outcomes, and associated factors of these invasive GAS cases.
• To evaluate the implications for public health policy, particularly regarding vaccination.

Main Methods:

• Retrospective review of all invasive group A streptococcus (GAS) cases referred to the Paediatric Infectious Disease (PID) department of Children's University Hospital (CUH) in 2016.
• Data collection included case demographics, clinical presentation, severity of illness (e.g., ICU admission), length of stay, and co-existing conditions.
• Specific attention was paid to the association with concurrent infections, particularly varicella (chickenpox).

Main Results:

• Ten cases of invasive GAS were identified, all occurring within a concentrated 16-week period (February to June).
• A significant proportion (60%) required pediatric intensive care unit (PICU) admission, with a median length of stay of 21.5 days.
• Seven out of ten cases (70%) had active chickenpox infection at the time of diagnosis, indicating a strong association.

Conclusions:

• Invasive group A streptococcus (GAS) infection in children is associated with significant morbidity in Ireland.
• The high proportion of cases linked to chickenpox, a vaccine-preventable illness, is a critical finding.
• The study strongly suggests a reappraisal of the absence of the varicella vaccine from Ireland's national immunization schedule.