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The physical space of the MSK Library is permanently closed to visitors as of Friday, May 17, 2024. Please visit this guide for more information.
An outbreak means more disease than expected. Measles is extremely contagious. Around 9 out of 10 people who are not protected will become infected following exposure to the measles virus. Measles outbreaks are declared when the number of cases reported in an area is higher than the expected number of cases.
Over 61 million doses of measles-containing vaccine were postponed or missed from 2020 to 2022 due to COVID-19 related delays in supplementary immunization activities. This increases the risk of bigger outbreaks around the world.
Provisional data based on monthly data reported to WHO (Geneva) as of early February 2024.
Data covers July 2023 – December 2023
|
Country |
Case Count |
|---|---|
| Yemen | 18,464 |
| Azerbaijan | 13,721 |
| Kazakhstan | 13,195 |
| India** | 12,301 |
| Ethiopia | 10,060 |
| Russian Federation | 7,720 |
| Iraq | 7,601 |
| Pakistan | 7,027 |
| Kyrgyzstan | 5,777 |
| Indonesia | 3,205 |
**WHO classifies all suspected measles cases reported from India as measles clinically compatible if a specimen was not collected as per the algorithm for classification of suspected measles in the WHO VPD Surveillance Standards. Thus numbers might be different between what WHO reports and what India reports.
The European Centre for Disease Prevention and Control (ECDC) warned of a continuing rise in measles in the coming months, due to a spike in cases at the end of 2023 that has continued into the new year, suboptimal vaccine coverage, and the approach of the seasonal peak of the virus.
The group said the rise in cases is mainly due to drops in measles-containing vaccine coverage that occurred during the 2020-2022 COVID-19 pandemic period. Global activity has spiked, fueling a rise in travel-related cases, with Yemen, India, and Ethiopia reporting the most cases in 2023. In Europe, measles activity picked up in 2023, with outbreaks reported in Romania, Austria, and France.
So far this year, the ECDC has recorded an increasing number of countries reporting cases, with 2,361 reported so far, 5.4% of them imported. At least seven deaths have been reported, six from Romania and one from Ireland.
Though measles-containing vaccine coverage didn't decline as much in Europe during the pandemic as in some other parts of the world, many European countries are below the 95% coverage needed to achieve and sustain measles elimination.
There was an "alarming" nearly 45-fold increase in measles cases in Europe last year, the World Health Organization (WHO) says.
Health chiefs are warning that cases are still rising and "urgent measures" are needed to prevent further spread. Some 42,200 people were infected in 2023, compared to 941 during the whole of 2022. The WHO believes this is a result of fewer children being vaccinated against the disease during the Covid pandemic.
On 19 January, the UK Health Security Agency (UKHSA), the public-health authority, declared a national incident over rising cases of measles. The agency has logged more than 300 cases in England since 1 October 2023.
Low uptake of the measles vaccine is a key driver of the UK measles cases, say researchers. Around 85% of children in England have received two MMR vaccine doses by five years old, according to data from the National Health Service (NHS). This falls below the vaccination rate of at least 95% needed to achieve ‘herd immunity’ — which substantially reduces disease spread — as recommended by the World Health Organization.
On 22 January, the NHS launched a vaccination campaign, urging millions of parents and carers to book vaccine appointments for their children. Health services will contact all parents of unvaccinated children aged 6 to 11. “If parents and young people respond to the information, and the message to get vaccinated, we could stop it in its tracks,” says Bedford.
Vaccination rates are lowest in London, where just 74% of children have received two doses of the vaccine. Two doses are 97% effective against catching measles. One local council in the capital has launched a vaccine-awareness campaign in multiple languages to reach more people.
In 2023, significant increases in the number of measles cases and outbreaks were observed globally, including in 40 of the 53 countries of the European region, and in at least ten EU/EEA countries. Measles cases are expected to continue increasing in the EU/EEA in the coming months due to sub-optimal vaccination coverage for measles containing vaccines (MCV) in a number of EU/EEA countries, the high probability of importation from areas experiencing high circulation and the fact that the coming months represent the seasonal peak of the virus.
The risk from measles was assessed for four different population groups by the probability of infection and its impact. The overall risk is assessed as moderate for infants <12 months of age for whom vaccination is not indicated in most countries, and for children ≥1-5 years of age who are known to be at risk of higher morbidity and mortality due to measles complications. In addition, the overall risk is assessed as moderate for immunocompromised persons. Older unvaccinated children (>5 years of age) and unvaccinated adults are estimated to have low to moderate risk from measles, as they do not usually present with severe disease or complications. Finally, for the population that is immune to measles, the risk is low due to the high protection conferred by the two-dose vaccination scheme or the lifelong protection from natural disease.
ECDC encourages EU/EEA public health authorities to focus on the following activities in view of the expected rise of measles cases:
In the EU/EEA, measles activity began to increase in 2023 after a period of unusually low activity in 2020–2022, which coincided with the COVID-19 pandemic. During 2023, while many EU/EEA countries continued to report no or very low (sporadic) cases, measles outbreaks were reported by several other countries (Romania, Austria, and France).
The outbreak in Romania has been ongoing since mid-February 2023, and on 5 December 2023, the Ministry of Health declared a national measles epidemic. In 2023, there were 2,361 measles cases reported to ECDC by EU/EEA countries, of which 1,755 (74.3%) were reported by Romania. More recent figures from the Romanian Institute of Public Health show that Romania has detected 4,679 confirmed cases between 1 January 2023 and 6 February 2024.
During January and February 2024, ECDC observed an increasing number of EU/EEA countries reporting measles cases, with six fatal cases reported in Romania and one in Ireland.
Of the 2,361 cases reported by EU/EEA countries between 1 January to 31 December 2023, 5.4% (128) were recorded as having been imported and a further 0.9% (22) were recorded as import-related cases, meaning the source of infection (exposure) was outside the reporting country. Although there is variation in the proportion of imported cases by country, the overall majority of people have acquired the disease within the reported country through community/local transmission.
During the period 1 January to 31 December 2023, the notification rate per 1 million population was highest in:
Seven countries reported no cases in 2023 (Bulgaria, Cyprus, Greece, Iceland, Luxembourg, Malta, Slovenia).
According to data reported to The European Surveillance System (TESSy), measles cases in EU/EEA countries were reported across all age groups between 1 January and 31 December 2023, with the highest number of cases among children aged 1–4 years, followed by children aged 5–9 years.
This overall trend is largely driven by the situation in Romania, and a few other countries follow the same trend. However, other EU/EEA countries have reported the highest proportion of cases in other age groups, such as children aged 10–14 years (e.g. France), or adults aged 30 years and older (e.g. Germany, Italy, the Netherlands). This highlights that measles can affect all age groups.
Overall, 75.7% of cases reported in 2023 (1,786 of 2,361) were unvaccinated. The proportion of unvaccinated cases varied by age group: it was highest among children aged less than 1 year (94.2%), who in the majority of countries are too young to be vaccinated, and was lowest among adults aged 30 years and over (where 46.7% were unvaccinated and 36.2% had unknown vaccination status). The trends in age groups and proportion of unvaccinated individuals is similar to previous years (data available in previously published Annual Epidemiological Reports).
The attenuated live measles vaccine is highly effective. However, due to the high transmissibility of the measles virus, very high vaccination coverage (≥95%) with two doses of measles-containing vaccine (MCV) is necessary to interrupt measles transmission. The latest national vaccination coverage estimates up to 2022 for MCV dose 1 and dose 2 are available from the WHO Global Health Observatory.
In 2022, the EU/EEA experienced a slight decline in average vaccination coverage compared to 2018. The mean vaccination coverage for the first dose of measles-containing vaccine (MCV1) decreased from 95% in 2018 to 92% in 2022. Within the EU/EEA, 16 Member States observed a decrease in MCV1 coverage, ranging from a 1% to 24% decrease, while five Member States observed an increase ranging from 1% to 3%. Similarly, the mean coverage for the second dose (MCV2) decreased from 91% in 2018 to 89% in 2022, with 13 Member States reporting a decrease (1% to 23%) and seven Member States reporting an increase (1% to 12%).
Based on the 2022 data, only 50% of EU/EEA countries reported a coverage of ≥95% for the first dose [12] and only 17% achieved this threshold for the second dose. Only four countries had an estimated coverage of ≥95% for both MCV1 and MCV2 in 2022.