New measles surveillance data from WHO

New measles surveillance data is now available on the WHO website. This preliminary data is based on country reports submitted monthly to WHO. Please note that these are not final estimates as countries are still reporting cases and discarding cases based on laboratory results. Through WHO and UNICEF’s joint reporting channels, final official annual total numbers are made available in July of the following year.

Data from this summary should therefore be reported as provisional and clearly dated (i.e. “provisional data based on monthly reports to WHO (Geneva) as of August 2019”).

GENEVA, 12 August 2019 — Measles outbreaks continue to spread rapidly around the world, according to the latest preliminary reports provided to the World Health Organization (WHO), with millions of people globally at risk of the disease.

In the first six months of 2019, reported measles cases are the highest they have been in any year since 2006, with outbreaks straining health care systems, and leading to serious illness, disability, and deaths in many parts of the world. There have been almost three times as many cases reported to date in 2019 as there were at this same time last year.

This follows successive yearly increases since 2016, indicating a concerning and continuing upsurge in the overall measles burden worldwide.

The Democratic Republic of the Congo, Madagascar and Ukraine have reported the highest numbers of cases this year. However, cases have dramatically decreased in Madagascar in the past several months as a result of nationwide emergency measles vaccine campaigns, highlighting how effective vaccination is in ending outbreaks and protecting health.

Major outbreaks are ongoing in Angola, Cameroon, Chad, Kazakhstan, Nigeria, Philippines, South Sudan, Sudan and Thailand.

The largest outbreaks are in countries with low measles vaccination coverage, currently or in the past, which has left large numbers of people vulnerable to the disease. At the same time, protracted outbreaks are occurring even in countries with high national vaccination rates. This results from inequities in vaccine coverage, and gaps and disparities between communities, geographic areas, and among age-groups. When enough people who are not immune are exposed to measles, it can very quickly spread.

The United States has reported its highest measles case count in 25 years. In the WHO European region, there have been close to 90,000 cases reported for the first six months of this year: this exceeds those recorded for the whole of 2018 (84 462) – already the highest in this current decade.

The reasons for people not being vaccinated vary significantly between communities and countries including —lack of access to quality healthcare or vaccination services, conflict and displacement, misinformation about vaccines, or low awareness about the need to vaccinate. In a number of countries, measles is spreading among older children, youth and adults who have missed out on vaccination in the past.

With governments and partners such as the Measles & Rubella Initiative, Gavi, the Vaccine Alliance and others, WHO is helping countries stop outbreaks, strengthen health services, and increase essential vaccination coverage.

Measles is almost entirely preventable with two doses of measles vaccine, a safe and highly effective vaccine. High rates of vaccination coverage – 95% nationally and within communities – are needed to ensure that measles is unable to spread.

According to WHO and UNICEF coverage data released in July 2019, 86% children have received the first dose of measles vaccine and 69% the second. This means that around 20 million children in 2018 received no measles vaccine through their routine vaccination programmes. Furthermore, 23 countries have yet to introduce the second measles vaccine dose into their national schedule.

WHO is urging everyone to ensure their measles vaccinations are up to date, with two doses needed to protect against the disease, and to check their vaccination status prior to travel.

According to its latest travel recommendations, everyone 6 months and older should be protected against measles prior to travel to an area where measles is circulating. Anyone unsure of their vaccination status should consult with their healthcare provider. WHO recommends that travelers get vaccinated against measles at least 15 days prior to travel.

Notes

While providing a strong indication of overall trends, monthly surveillance data is provisional and incomplete, as many countries – particularly those experiencing major outbreaks – are still reporting data and conducting laboratory testing. Due to delays in reporting, there may therefore be discrepancies between what is presented in these reports and what is reported directly from countries.

The actual numbers of cases – captured in global estimates released annually – are considerably higher than those reported through surveillance systems because of incompleteness of reporting. WHO estimates that globally fewer than 1 in 10 cases are reported; the completeness of reporting varies substantially by country. The latest year for which WHO global measles case and death estimates are available is 2017; in that year there were 6.7 million estimated measles cases and 110,000 estimated measles-related deaths, based on 173,330 reported cases. In 2018 there were 353,236 measles cases reported to WHO. Global case and death estimates for 2018 will be released by WHO in November 2019.

With the provisos described above, for the period of January 1 through July 31 2019, 182 countries reported 364,808 measles cases to WHO. For this same period last year, 129,239 measles cases were reported from 181 countries. For the current 2019 period, the WHO African Region has recorded a 900% (i.e. a 10-fold increase) increase, the European Region 120% (more than twofold increase), the Eastern Mediterranean Region 50% (1.5 fold increase), the Western Pacific Region 230% (a threefold increase); the South-East Asia Region and the Region of the Americas each saw a 15% decrease in reported cases.

Measles transmission is typically seasonal, peaking in spring in temperate climates and after the rainy season in the tropics.