Annual regional measles incidence increased in the World Health Organization (WHO) Eastern Mediterranean region from 33.5 per million population in 2013 to 91.2 per million population in 2018; in 2019 it decreased dramatically to 23.3. These findings were published in the CDC’s Morbidity and Mortality Weekly Report, to aid in describing progress toward measles elimination in EMR during 2013-2019.
In 1997 the resolution to eliminate measles in the Eastern Mediterranean region was passed by the WHO Regional Committee for the Eastern Mediterranean and the 21 countries of the Eastern Mediterranean region. In 2015, this goal was included as a priority in the Eastern Mediterranean Vaccine Action Plan 2016-2020 (EMVAP).
For this a 4-pronged strategy was developed:
1. Achieve ≥95% vaccination coverage with the first dose of measles-containing vaccine (MCV1) among children in every district of each country through routine immunization services.
2. Achieve ≥95% vaccination coverage with a second MCV dose (MCV2) in every district of each country either through implementation of a routine 2-dose vaccination schedule or through supplementary immunization activities.
3. Conduct high-quality, case-based surveillance in all countries.
4. Provide optimal measles clinical case management, including dietary supplementation with vitamin A.
An update on the progress found that estimated MCV1 coverage between 2013 and 2018 increased from 79% to 82%. During the same period, MCV2 coverage increased from 59% to 74%. In addition to these increases, between 2013 and 2019, approximately 326.4 million children received MCV during supplementary immunization activities. Further, in 2018, 52% of the 21 Eastern Mediterranean region countries attained >95% coverage with both vaccines.
The reported increases in measles incidence between 2013 and 2018 (31.5 vs 91.2 per 1 million persons, respectively) was attributed to large outbreaks in Pakistan, Yemen and Somalia. However, 2019 demonstrated a significant decrease in the incidence of measles; the rate of discarded non-measles cases, defined as suspected cases that were determined not to be measles using laboratory testing or epidemiologic linkage to a laboratory-confirmed outbreak of another communicable disease that is not measles, was 5.4 per 100,000 population. Overall, between 2013 and 2019, the rate of Eastern Mediterranean region countries that met the target of suspected cases discarded as non-measles increased from 67% to 86%; further, the percentage of suspected cases with adequate investigations increased from 76% to 86%.
The researchers highlighted that by the end of 2019, 14% of Eastern Mediterranean region countries demonstrated measles elimination.
Investigators noted 2 limitations to these findings. Firstly, administrative coverage may overestimate vaccination coverage by erroneously including supplementary immunization activity doses or those administered to children outside target age groups, inaccurate estimates of the target population size, and/or inaccurate reports of the number of doses delivered. Secondly, surveillance data likely underestimate incidence as not all patients seek care and not all that do are reported.
Although the MCV1 and MCV2 coverage did improve they remained below the WHO-recommended level of ≥ 95% and the large-scale outbreaks revealed persistent suboptimal coverage. Civil unrest, armed conflict and unpredictable mass population displacements represent major challenges to implementing elimination activities in several Eastern Mediterranean countries, while other countries have achieved and maintained elimination.
To accelerate progress in the Eastern Mediterranean region investigators believe that the visibility of elimination efforts and the benefits of achieving elimination need to be increased. Investments to increase MCV coverage, conduct high-quality supplementary immunization activities and to reach populations at risk for inaccessibility of services or living in areas of civil strife will also be required. Furthermore, investigators stated that in order to achieve vaccination and equity targets that leave no one behind and quicken progress toward measles elimination, broader EMVAP and Immunization Agenda 2030 goals, “sustained and predictable investments and careful management of the leveraging of the substantial polio eradication infrastructure and resources are critically needed.”
Goodson JL, Teleb N, Ashmony H, et la. Progress toward measles elimination – Eastern Mediterranean Region, 2013-2019. Morb Mortal Wkly Rep. 2020;69:439-445.