1 Summary

• From 1 January 2025 to 28 February, 13 clinically suspected measles cases have been notified to the Public Health Agency.
• Of those notified during 2025 to 28 February, two were laboratory confirmed and one epidemiologically confirmed.

2 Background

Measles is a systemic viral infection caused by the measles virus. It is normally characterised by a fever, rash and respiratory illness. For more information about measles please visit NI Direct | Measles.

A vaccine against measles, which also provides protection against mumps and rubella (MMR), is included in the Northern Ireland childhood vaccination schedule at one year of age and at three years and four months. A regional MMR ‘catch-up’ campaign was delivered in Northern Ireland between February and June 2024 for anyone aged from one to 25 years, who had not already had two doses of MMR. For more information please visit NI Direct | MMR catch-up campaign, NI Direct | MMR and NI PHA | MMR vaccine catch-up.

Public and clinician awareness of measles has changed over time, especially during February 2024, which may have contributed to changes in trends.

Details of case definitions and methods are at the end of this document. Data were correct at 28 February 2025.

3 Measles notifications, 2024-2025

The number of notified clinically suspected measles cases from the start of 2024 until the report date (28 February 2025) are shown (Table 3.1).

Please note: in the table above data for 2025 is up to 28 February

3.1 Trends

Measles notifications in Northern Ireland increased during February 2024 before decreasing by the end of March 2024 (Figure 3.1). There were 21 laboratory confirmed measles cases reported in 2024 with the last confirmed case reported in September 2024. Measles notifications have remained low since October 2024 and there have been two laboratory confirmed measles cases and one epidemiologically confirmed case reported in 2025 to date. The supplementary table below shows counts of measles notifications recorded by month.

Figure 3.1: Incidence of measles notifications, by month and year of notification, all ages, 2024 - 2025.

4 Discussion

There have been two laboratory confirmed cases and one epidemiologically confirmed cases of measles reported during 2025 to 28 February 2025. There were 21 laboratory confirmed cases during 2024, the first since 2017. There was an increase in notifications of clinically suspected measles during February 2024, likely due to increased awareness and reporting. There is an increased risk of measles outbreaks due to a reduction in MMR vaccine coverage in Northern Ireland during recent years NI PHA | MMR vaccine coverage. Increasing coverage of the MMR vaccine is crucial to ensure widespread protection and prevent outbreaks of measles.

5 Methods

Measles notifications are reported by clinicians to the Public Health Agency and were extracted from the case management database. Measles is notifiable in Northern Ireland under the Public Health Act (1967) Northern Ireland.

Cases are presented by the date that they were recorded on the PHA database. Notified cases will be removed from future reports if PHA is notified that clinical investigations later result in an alternative diagnosis. Numbers may therefore reduce.

Data were processed in R.

6 Supplementary Table