Eliminating measles in Europe by 2010 may be difficult, study suggests
A large-scale study of measles in 32 European countries, conducted by the EU-funded vaccination surveillance network EUVAC.NET has brought to light more than 12,000 cases of the disease between 2006 and 2007, mostly in unvaccinated or incompletely vaccinated children. The countries most affected were the UK, Germany, Italy, Romania and Switzerland. Increased measles transmissions were seen in the beginning of 2008, notably in the UK, Italy, Switzerland and Austria. The data, published in the journal The Lancet, has major implications for the World Health Organization's (WHO) goal of eliminating measles in Europe by 2010. The results also highlight the potential for strains of the virus to be exported from Europe to countries with substandard healthcare, where fatality rates are substantially higher. Measles is highly contagious and was responsible for more than 30 million cases and 530,000 deaths globally in 2003. Immunisation has proven to be a cost-effective and life-saving way to control and potentially eliminate measles, and effective immunisation programmes have been part of public health services in Europe for around 40 years. Nevertheless, in Europe an estimated 4,850 deaths were caused by measles in 2003. In 2005, a World Health Assembly resolution urged countries to strengthen national immunisation programmes between 2006 and 2015. Europe has since targeted measles elimination as a priority, especially in light of the fact that a significant portion of measles cases imported into the US and Canada between 1999 and 2001 were linked to the European region. The EUVAC.NET study, which was coordinated by the Statens Serum Institute in Denmark, examined data from national surveillance institutions to determine the incidence of measles and the age groups most affected. The researchers looked at age-group, diagnosis confirmation, vaccination history, hospitalisation, and the presence of acute encephalitis as a complication of disease and death; in 30 countries information about the importation of the disease was also collected. Age groups were babies under a year old; toddlers aged 1 to 4 years; children 5 to 9 years, 10 to 14 years, and 15 to 19 years; and adults aged 20 years and older. For the 2 years of the study, 12,132 cases of measles were recorded. While most of these were in unvaccinated or incompletely vaccinated children, almost a fifth were in adults aged 20 years or older. Of the 210 cases reported as being 'imported' from another country, 117 (56%) came from within Europe and 43 (20%) from Asia. To eliminate measles, countries must ensure a minimum of 95% vaccination coverage that includes two separate doses of the vaccine. Crucially, public health programmes must 'better target susceptible individuals in the general population and high-risk groups', according to the WHO strategic plan for Europe between 2005 and 2010. Most of the countries that experienced measles outbreaks reported suboptimum measles vaccination coverage over a long period. Switzerland reported 82% coverage over the past 17 years, and in the UK, measles vaccination coverage was below 85% between 2002 and 2005. In Ireland, coverage has increased significantly since 2003 but remains below 90%. In Germany, vaccination of children born between 1996 and 2003 was consistently around 70%. In Italy, coverage for children aged 2 has also increased since 2003, but remains below 90%. In all countries studied, there was large variation in vaccination coverage between regions. Importantly, countries with no measles incidence reported consistently high measles vaccination coverage over long periods, highlighting the effectiveness of vaccination programmes. Studies of Finnish populations, for example, have shown a consistent vaccination rate of above 95%. 'For achievement of the measles elimination goal, awareness of the disease and commitment by decision makers and public health authorities in all European countries are essential to strengthen vaccination programmes,' the study reads. 'We need to identify barriers for measles vaccine uptake and explore methods to target vulnerable populations that have been hard to reach with standard programmes. Records of measles vaccination uptake are also important to monitor progress and allow early identification of suboptimum vaccination coverage.' The study also advises strengthening surveillance systems, so that suspected measles cases may be thoroughly and quickly investigated. The researchers also recommend continuing epidemiological and laboratory investigations as well as measles virus genotyping to identify transmission patterns and control the spread of the disease. 'Failure to implement these elimination strategies by all European countries raises concerns for the successful and continued interruption of measles virus transmission,' the authors conclude. 'The suboptimum vaccination coverage raises serious doubts that the goal of elimination by 2010 can be attained. Achievement and maintenance of optimum vaccination coverage, and improved surveillance, are the cornerstones of the measles elimination plan for the Europe.' In an accompanying editorial, Dr Jacques Kremer and Dr Claude Muller of the WHO Regional Reference Laboratory for Measles and Rubella in Luxembourg emphasise the need for countries to identify and monitor specific obstacles to measles elimination, and to design appropriate responses. They cite the recent unsubstantiated scare in the UK linking measles vaccine to autism, the suspension of vaccination programmes in the Ukraine, disruption of vaccine supplies due to political unrest in the Balkans and religious objectors in the Netherlands, among many other barriers to wiping out the disease. The importance of addressing these obstacles to measles elimination goes beyond Europe to the more vulnerable countries affected by Europeans, they say. 'The more pressing question is how much measles does Europe export to countries with poor health systems and high fatality rates. Importations of measles virus from Europe have already triggered several outbreaks in South America [...]. Rich countries need to be responsible for avoiding cases by implementation of high vaccination coverage, to make it the privilege of resource-poor countries not to worry about reintroductions from Europe.'