WHO EMRO Weekly Epidemiological Monitor: Volume 16; Issue no 07; 12 February 2023 – Ethiopia

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Attachments

Current major event

Situation update: Measles

Since the measles outbreak started in Afghanistan in January 2022, Afghanistan’s Ministry of Public Health has reported a total of 81 277 suspected cases of measles infection with 401 associated deaths at a case-fatality ratio of 0.5%, as of epidemiological week 6 of 2023. The week-on-week increase of cases is alarming with week 6 showing a 40% increase relative to week 1, despite robust vaccination campaigns. This increase is similar in scale to that observed in 2022 prior to a surge in cases and needs urgent response and monitoring.

Editorial note

Measles is an endemic disease in Afghanistan, and many countries in the Eastern Mediterranean Region, with seasonal surges in the cases reported annually across all regions of the country. Measles is caused by a morbillivirus of the paramyxoviridae family and is highly contagious, spreading through both respiratory pathways and contact transmission.

The virus is highly transmissible, as patients are considered contagious from 4 days before to 14 days after the symptom presentation. Symptoms include fever, sore throat and rash, but respiratory and neurological complications can result in fatalities. This occurs particularly in infants and children under 5 years, pregnant women and immunocompromised individuals.

Measles is a vaccine-preventable disease, with the MMR (measles, mumps, and rubella vaccine) widely used. Meta-analyses show that single or dual vaccine doses are 93% to 97% effective at preventing measles disease. Since 2021, there have been 5 outbreak responses to measles in Afghanistan, which have resulted in 11 million children being vaccinated. Afghanistan implemented a national vaccination campaign in December 2022 and has reached 5.3 million children, achieving 99% administrative coverage across 34 regions.

Despite this success, measles cases are increasing in Afghanistan (See graph).However, the weekly number of suspected cases decreased from epidemiological week 27 to week 35 of 2022, then it stabilized at a level of infection above the average of the past two years (2019–2020). This stabilization was driven by outbreak response work, including increased vaccination campaigns and in-country support for case management and treatment. WHO supported the distribution of 593 measles case management kits across the 34 provinces in further response to the outbreak and continues to monitor the situation closely.

Phase one of the measles outbreak response immunization was conducted between 12–18 March 2022 in 48 high-risk districts in 24 provinces. During this campaign, more than 1.2 million children aged 6–59 were vaccinated and around half of them were girls (50.2%). Measles cases are being managed in health facilities across the country. Additionally, as of week 17, 2022 a total of 165 measles kits were distributed by WHO, to Médecins Sans Frontières (MSF) and the International Committee of the Red Cross (ICRC) and the distribution to provinces is ongoing.

Of note, an increase in cases was observed since week 1, 2023, which is similar to that observed in 2022, when there was a week-onweek increase of 10–14% up to the peak of infection in week 14. This increase could be associated with lower immune resistance due to harsh environmental conditions. It has been noted in other regions of endemic infection, where vaccine uptake has been suboptimal that there can be break-out strains of measles, which should be monitored closely.

A further 2000 at risk children (aged 9–59 months) were vaccinated in the past week in response to the increase in measles cases as part of ongoing outbreak response immunization activities. WHO is also working to strengthen and expand the capacity of the national laboratory network to ensure timely diagnosis of measles, strengthening surveillance, case management, risk communication and community engagement and coordinating vaccination activities to areas of highest concern.



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