Measles Outbreak in Macedonia: Epidemiological, Clinical and Laboratory Findings and Identification of Susceptible Cohorts

OBJECTIVES Despite a 92-99% national vaccination coverage since 2000, the former Yugoslav Republic of Macedonia experienced a large measles outbreak between 2010 and 2011. Here we investigate the characteristics of patients hospitalized during this outbreak at the Clinic of Infectious Diseases in Skopje. METHODS Epidemiological, clinical and laboratory data of 284 measles patients, including 251 from Skopje (43.80% of the 573 reported cases) and 33 from elsewhere in Macedonia were collected. RESULTS The most affected age groups were children up to 4 years of age and adolescents/adults of 15 years and older. Most patients were unvaccinated (n=263, 92.61%) and many had non-Macedonian nationalities (n=156, 54.93%) or belonged to the Roma ethnicity (n=73, 25.70%). Bronchopneumonia and diarrhea were the most common complications. Eighty-two out of 86 tested patients (95.35%) had measles-specific IgM antibodies. The outbreak was caused by the measles variant D4-Hamburg. CONCLUSIONS The epidemic identified pockets of susceptibles in Skopje and indicated that additional vaccination opportunities in particular for people with non-Macedonian nationality and traveler communities are warranted to ensure efficient measles control in Macedonia. The high attack rate among children of less than 1 year suggests that vaccination before 12 months of age should be considered in high risk settings.