Measles in 2011: devastating, surprising outbreaks and some success

Measles continued to make a disturbing comeback in 2011, with several new and ongoing outbreaks of this vaccine-preventable virus. These included outbreaks in countries with some of the best, and, some of the worst health systems in the world. Encouragingly, many countries with support of the Measles Initiative stopped measles outbreaks that had been a concern in 2010, through improved routine and supplementary immunization. These countries dramatically reduced cases and incidence, demonstrating that this deadly virus can be eliminated with high coverage of measles vaccine.

Here is a snapshot of the measles highlights and challenges of 2011 with a focus on measles incidence per 100,000 people according to data as of 11 January 2012:

Highest measles incidence 2011:

Timor Leste experienced a large outbreak in early 2011, with more than 1500 cases recorded. Given the country’s relatively low population, this meant an annualized measles incidence of 142.86 per 100,000 people, the highest measles incidence in the world in 2011. The Timor Leste Ministry of Health mounted an outbreak response campaign with support from partners including AusAID and UNICEF in mid-2011, targeting all children aged 6 months to 14 years – about half the population of the country.

Zambia also suffered high measles incidence with outbreaks continuing from 2010. The country recorded more than 13,000 measles cases in 2011 for an incidence of 106.46 per 100,000, which was only slightly better than 2010 when the country recorded about 15,500 cases. The Government worked with the Measles Initiative and Médecins Sans Frontières to mount an outbreak response in May 2011, targeting about 600,000 children, and new measles cases had dropped sharply by July. Zambia is now planning for a nationwide campaign in 2012.

Most surprising measles incidence in 2011:

Two European countries, France and the Former Yugoslav Republic of Macedonia, recorded the 3rd and 4th highest measles incidence globally in 2011, with 38.53 and 26.05 per 100,000 people respectively. These outbreaks continued from 2010, and affected other European countries including Belgium, Italy, Ireland, Serbia and Romania. Overall, European countries account for a quarter of the countries with >5 cases per 100,000 people in 2011. Measles virus from Europe was connected to outbreaks in the U.S., Canada, Australia and Brazil. France recorded more than 15,000 cases in 2011, and the outbreak is expected to continue in 2012. Macedonia conducted a measles campaign in mid-2011; and France has increased communication and adjusted its measles vaccination schedule to increase coverage, including of adolescents and adults who have been most affected by the outbreaks. Read this report and this news release for more on European outbreaks in 2011.

New Zealand also continues to battle a large measles outbreak that caused incidence to spike to 12.06 per 100,000 – the highest in the Western Pacific region. The outbreak was traced to five people who were infected on a flight from Singapore, and the virus then spread through communities which had either refused vaccination or were under-immunized. New Zealand has stepped up outreach, is encouraging everyone under 42 years of age to ensure their vaccinations are up-to-date, and adjusted its immunization schedule to accelerate two dose coverage to young children.

Most devastating measles outbreaks in 2011:

Somalia, the Democratic Republic of the Congo and Nigeria all recorded high numbers of measles cases in 2011. The massive outbreak in the DR Congo infected at least 133,000 people and killed more than 1,500. The country mounted localized responses with support of the Measles Initiative. Somalia and camps for displaced Somalis experienced more than 11,000 cases in 2011, which became particularly deadly during the drought and famine. Partners in the Measles Initiative and NGOs including Médecins Sans Frontières offered measles vaccination in camps and in areas that were safe, though campaigns were disrupted by violence and a ban on access by Al-Shabaab fighters. Health partners plan more campaigns for early 2012 and will deliver additional health interventions including polio vaccine, vitamin A and deworming tablets. Nigeria recorded more than 21,000 suspected measles cases in 2011, compared with more than the 14,000 suspected in 2010. This is particularly worrying given Nigeria conducted a nationwide measles vaccination campaign in early 2011 which would have largely stopped the outbreaks if routine immunisation and campaign coverage had been high enough.

Biggest outbreaks in the Americas:

The Americas were certified measles-free in 2002, but pockets of unimmunized children continue to be at risk of virus importations. In 2011, the U.S. recorded the largest number of measles cases in fifteen years with 223 cases, all of which were connected to importations from infected countries including France. Ecuador also suffered an outbreak of almost two hundred cases traced to virus from abroad. However the largest outbreak occurred in Canada with more than 800 cases, mostly in the province of Quebec. The province has mounted a campaign to increase coverage of school children. These cases in the Americas demonstrate that until measles is eliminated everywhere, it remains a threat to children around the world.

Greatest reduction in measles cases:

Southern African countries including Botswana, Malawi, Lesotho, Swaziland and Zimbabwe mounted responses to large measles outbreaks in 2010, and succeeded in reducing incidence dramatically by 2011. The response efforts, supported by the Measles Initiative, targeted children up to 14 years of age as older children comprised a large proportion of cases. By 2011 most countries saw a dramatic drop – Malawi for example recorded more than 73,000 cases in 2010, and fewer than 30 in 2011. All of these countries will now need to maintain high routine immunization coverage with MCV1, and ensure a 2nd dose is offered either through routine services or timely supplementary immunization to keep measles at bay.

Measles Efforts Paying Off:

China has traditionally had one of the highest measles incidence in the world. However China conducted a nationwide campaign in September 2010 targeting 100 million children –one of the largest public health efforts ever mounted. The result, as reported by the Ministry of Health, is a near 74% drop in measles cases to under 10,000 as of end November 2011.

India has also traditionally recorded amongst the most measles cases and highest measles mortality in the world. In 2010, 17 states began to offer a second measles dose as part of the routine immunization schedule; and the country is now leading a phased campaign to offer 134 million children in higher-risk areas a 2nd dose through supplementary immunization. India has recently celebrated an historic one year of zero new polio cases – a milestone recognized globally. The Measles Initiative congratulates India for its polio-free achievement, and for its renewed measles efforts.

The Peoples Democratic Republic of Laos held its first national combined Measles-Rubella campaign in late 2011, with support of the Measles Initiative. With steadily improving routine immunization and high campaign coverage, Laos may stop measles and rubella completely in 2012.

Data sourced from 11 January 2012:

  • Note that the quality of measles surveillance varies from country to country and depends on health and information systems. Some countries may be experiencing larger measles outbreaks than are reported as every case is not detected and laboratory confirmed.
  • Data for China and India are not available for this table; and data from Somalia and the Democratic Republic of the Congo are not complete so these four countries are not represented on the table above.

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