Magnitude and trends of measles in north west of Tigray Region, Ethiopia - A four-year surveillance data analysis, 2012-2015

Abstract

Introduction: Globally, measles is the leading cause of morbidity and mortality despite the availability of safe and effective vaccine. In Ethiopia, measles remains a disease of public health importance with an annual incidence of 12.5 to 18 per 100,000 populations. This study aimed at identifying the magnitude and trends of measles in the Northwest zone of Tigray region. Methods: We conducted a descriptive surveillance data analysis from 2012-2015 in the Northwest zone of Tigray region. We reviewed line list records and Health Information Management System reports. A suspected measles case was defined as any person with fever, rash, cough and either conjunctivitis or coryza. Laboratory confirmed cases had measles-specific IgM antibodies, and epidemiologically confirmed cases were those linked to a laboratory-confirmed case. We collected data by a standardized checklist, and analyzed it using Epi-info 7.1.5 and Microsoft Excel worksheet. We presented the analyzed data using frequencies, proportions, median and range. Results: We identified 757 measles cases with an annual incidence of 39 and 16 per 100,000 in 2012; 77 and 67 per 100,000 in 2015 in the <5 and >15-year-old respectively. Among these cases, 380(62%) were unvaccinated. Among <5 children, 27(3.6%) were <9-month infant ineligible for routine measles vaccination. Measles occurrence had a cyclical pattern from November to April, with high peaks from February to April. Conclusion: Children <5 years and adults aged ≥ 15 years were more affected in a cyclical occurrence of measles. Routine and supplementary immunization activities for more affected age groups including at-risk adults, and early preparedness before November may limit occurrence and spread of measles.