WHO EMRO Weekly Epidemiological Monitor: Volume 12, Issue 22 (2 June 2019)
Current major event
Measles situation in EMR
In the first 3 months of 2019, a total of 5 647 cases of measles has been reported from 19 countries in the Eastern Mediterranean region (EMR). The most affected countries this year include Somalia (1 204), Sudan (1 168), Saudi Arabia (808), Pakistan (751), Tunisia (659) and Lebanon (568).
Measles remains one of the most contagious viral diseases with a significant public health impact, particularly amongst children. Most measles-related deaths are caused by severe complications related to the disease including otitis media, blindness, encephalitis, diarrhea and pneumonia. It can also contribute to mortality by exacerbating malnutrition and vitamin A deficiency. Measles has been one of the leading causes of childhood deaths in the humanitarian emergencies globally, including the EMR. The disease is almost entirely preventable through two doses of a safe and effective vaccine. The Region's coverage has stalled at 81% for the first dose and 67% for the second (see table), not even close to the WHO's herd imnunity target of 95%, leaving many children in many countries at risk.
Preliminary data shows that reported cases from countries in EMR in the first three months of 2019 (5 647) are 33% less than the reported cases in the same period in 2018 (8 426). However, consecutive increase of cases over the past two years should be the main public health concern (see graph). Some countries in the region are experiencing a large measles outbreak in the last few months. This may be due to the low vaccination (MCV1) coverage among young children in most affected countries and the increased population movement (internal displaced persons and refugees) in the region, which contributes to the reported low measles coverage.
It is also concerning that countries which usually report no or very low number of cases in recent years with higher vaccination coverage (>80%) are now reporting spikes in case numbers (e.g. Tunisia, Saudi Arabia). This could be attributed to the disease spreading fast amongst clusters of unvaccinated populations. Not only do those susceptible clusters include internally displaced persons and refugees, but they also include the unvaccinated host populations. The vaccination coverage and the vaccination efficacy play an important role in accumulating this susceptible cohort over the years in a country. The existence of such a cohort poses high risk of introduction of measles and concurrent outbreaks on a larger scale.
WHO recommends countries in the Region need to adopt a proactive approach in analyzing their available data on a regular basis and planning supplementary immunization activities (SIAs) to cover the unimmunized cohorts as per the available resources and the suitable time frame to reach maximum immunization coverage. Displaced populations are more susceptible for measles infection and should be given special emphasis.
The risk of resurgence of measles infection in the EMR countries can pose a serious threat to the measles elimination goals set for 2020. If the situation worsens, it may halt the progress achieved so far in the Region. There is an urgent need for to enhance surveillance and expand measles vaccination coverage in all countries for maintaining high immunity levels amongst vulnerable population and preventing any future outbreak.
Source: World Health Organization