A Rise in Measles Reporting Two Years After the COVID-19 Pandemic: A Descriptive Analysis of Measles in Iraq in 2023 and Early 2024.

Background: The elimination of measles is a public health priority for the World Health Organization. During the COVID-19 pandemic from 2020 to 2022, the number of cases in Iraq decreased. However, a surge in cases started in late 2022. The aims of this study are to understand and describe the epidemiology of the surge of measles compared to reported cases in 2018 and 2019. Secondarily, they are to identify high clusters to find possible causes and implement prevention efforts accordingly, and low clusters of measles to identify possible protective factors. Methods: Frequencies were used to describe the univariate characteristics of cases reported each year. The chi-square test of independence was used to test differences by age; p-values less than 0.05 were considered statistically significant. Gi cluster analysis was used to determine where there were high and low clusters of cases in each district. Results: The number of clinically confirmed cases of measles rose dramatically in 2023 (14,301) and early 2024 (33,048) compared to 2018 (1044) and 2019 (4586). Most patients were less than one year to 14 years of age. The percentage of patients aged 5-14 years was higher in 2023 (32.8%) and 2024 (30.0%) than in 2018 (15.9%) and 2019 (22.1%). Males were consistently more prevalent than females throughout all study years. Almost 5% (1545) of patients were vaccinated; the remainder were unvaccinated or had unknown vaccination status. Only 1% reported a history of contact with infected patients. The case fatality ratio was 0.06% in 2023 and 0.2% in early 2024. Despite the recent surge in cases, 27 of the 153 districts (17.4%) had low clustering. Conclusions: The recent surge in measles cases in Iraq was found to be in those below 15 who are commonly associated with the disease. Clusters of high reporting were mainly in the middle of Iraq while clusters of low reporting were mainly in the north. We recommend continuing to study clusters of measles and vaccine coverage to direct prevention efforts.