Lessons from a system-wide response to a measles outbreak, Canterbury, February-April 2019

Despite New Zealand's "measles elimination" status, the risk of measles outbreaks persists, due to ongoing measles importation and sub-optimal vaccination coverage, including specific sub-populations with higher proportions of susceptible people. From February to April 2019, Canterbury experienced a measles outbreak with 38 local cases and an unidentified index case. The outbreak strain was linked to a large outbreak in the Philippines. The whole-of-health-system response included active case and contact follow-up by public health and hospital staff, and a prioritised vaccination campaign in primary care. Important features of a measles outbreak response in an "elimination" context include cross-system liaison, co-ordination of communications, careful prioritisation of use of available resources, and support for households affected by isolation and/or quarantine requests. Closer analysis of the effectiveness of outbreak control measures would help prioritise use of scarce public health and health care resources during outbreaks. Future measles outbreaks could be prevented by a systematic primary care-based MMR catch-up campaign.