Measles outbreak investigation in Ginnir district of Bale zone, Oromia region, Southeast Ethiopia, May 2019

Abstract

Introduction Measles is a vaccine-preventable viral infection of humans, primarily affecting children <5 years. During early 2019, outbreak of measles occurred in Ginnir district of Bale zone, Southeast Ethiopia. We investigated to describe the outbreak and identify risk factors. Methods We conducted a descriptive and 1:2 unmatched case-control study in Ginnir district from March 18 to April 29, 2019. Fifty-six cases and 112 controls were recruited. For descriptive study, we identified 1043 cases recorded on the line-list and for case-control study, cases were identified using national standard case-definition. Mothers of case-patients and controls were interviewed using structured questionnaire. We estimated vaccine efficacy (VE) from case-control study. We conducted bivariate and multivariable logistic regression. Results In four-months period, a total of 1,043 suspected measles cases epidemiologically linked to five laboratory confirmed cases reported. Of which, 555 (53.2%) were males and 714 (68.5%) were <5 years. The median age of cases was 36 months (IQR=12-60 months). The overall attack rate (AR) was 63/10,000 population with case fatality ratio of 0.5% (5 deaths/1043). Infant <9 months were the most affected age groups (AR=31/1000). Majority (79%) of measles cases were not vaccinated against measles. Last-year (2017/18) administrative measle vaccine coverage of the district was 76.7%. Being unvaccinated against measles (AOR=5.4, 95%CI=2.2-13.4), travel history (AOR=4.02, 95%CI=1.2-13.6), contact with measles case-patient (AOR=5.6, 95%CI=2.12-14.4) and mothers knowledge of measles transmission (AOR=0.36, 95%CI=0.15-0.87) were associated with measles infection. VE in children aged 9-59 months was 90% (95%CI=69-97%). Conclusion This confirmed measles outbreak was caused by failure to vaccinate, as indicated by the high VE, low administrative coverage, and 79% unvaccinated cases. Strengthening routine and supplementary immunization are required.

Evaluation of Measles Surveillance Systems in Ginnir District, Bale Zone, Southeast Ethiopia: A Concurrent Embedded Mixed Quantitative/Qualitative Study

“…8 Furthermore, there was a widespread outbreak of measles which affected 1,043 people, with five deaths in Ginnir district of Bale zone in 2019, and the outbreak lasted for 5 months. 9 The overall purpose of surveillance is to monitor the trends over time, detection of the occurrence of the diseases, identify the deviation from the threshold at the earliest point, and provide a prompt response. Furthermore, as an early warning system, it guides prevention of the disease before the occurrence of outbreak.…”

“…8 Furthermore, there was a widespread outbreak of measles which affected 1,043 people, with five deaths in Ginnir district of Bale zone in 2019, and the outbreak lasted for 5 months. 9 …”

Evaluation of Measles Surveillance Systems in Ginnir District, Bale Zone, Southeast Ethiopia: A Concurrent Embedded Mixed Quantitative/Qualitative Study&nbsp;

“…Our nding is supported by the report of study in Dangila district, Northwest Ethiopia [14]. According to the study of measles outbreak investigation in Ginnir district, the intervention activities to control the outbreak was initiated late by the district, after one month of the outbreak and the outbreak response immunization targeting children aged 6 months to 14 years was also initiated too late after two months [9]. Poor preparedness and response to the public health emergencies have an adverse consequence for the community.…”

“…Outbreaks occur when the accumulated number of susceptible individuals is greater than the critical number of susceptible individuals for a given population to sustain transmission [12]. However, the district health o ce was not investigated the measles outbreak which affected 1043 population with 5 deaths in 2019 [9], using epidemiological design. Study conducted in Dangila district, Northwest Ethiopia reported similar nding [14].…”

“…In the years 2019, a total of 8,202 suspected measles cases were reported from Oromia, Amhara, Afar and Somali region of Ethiopia [8]. Additionally, there was widespread measles outbreak which affected 1,043 population with 5 deaths in Ginnir district of Bale zone in 2019 and the outbreak lasted for the ve months [9].…”