Impact of a measles outbreak on a UK children's emergency department and the public health response: a retrospective observational study

Background: Measles outbreaks create a significant burden for healthcare facilities. We describe the impact of a large outbreak between October 2023 and June 2024 on Birmingham Children's Hospital Emergency Department (ED) in terms of cases and contact-tracing workload. Aim: To describe the impact of the outbreak in terms of case demographics, ED attendances, hospital admissions and post-exposure preventative measures. Methods: Confirmed cases were defined as individuals presenting to hospital and with laboratory confirmation (measles PCR positive). Epidemiological, clinical and laboratory data from public health case management systems and hospital records were analysed. Findings: A total of 366 patients attending ED were tested for measles. Of 161 confirmed cases, 40 (25%) were aged <1 year. Of 122 cases eligible for vaccination, 105 (86%) had no MMR vaccination. 32% (52/162) of confirmed cases attended ED more than once in the 21 days before being tested. Forty-six cases (29%) were admitted to hospital. Contacts were identified for 95 confirmed cases and 2397 exposure letters were sent. Thirteen confirmed cases had a symptom onset seven to 21 days after receiving an exposure letter. Conclusion: The outbreak led to significant pressure on the children's hospital ED in terms of case burden and contact tracing, with the potential for nosocomial spread. Future outbreak response should focus on prompt implementation of infection prevention and control measures; clear and timely messaging around symptoms for both families and clinicians; streamlined notifications; accelerated development of measles point-of-care testing; access to pop-up vaccination in the community; and better integrated working between public health teams and frontline clinicians.