A study of measles data from 32 European countries* has revealed more than 12,000 cases of the disease in a two-year period (2006-07), mostly in unvaccinated or incompletely vaccinated children. The cases, which came mainly from Romania, Germany, UK, Switzerland, and Italy, raise serious doubts that the goal of elimination of measles in Europe by 2010 can take place with suboptimum vaccination rates. The findings are revealed in an Article published Online first and in an upcoming edition of The Lancet, written by Dr Mark Muscat, Statens Serum Institut, Copenhagen, Denmark, and colleagues.
National surveillance institutions from the 32 countries submitted data for 2006-07, comprising details of age-group, diagnosis confirmation, vaccination, importation, hospitalisation, the presence of acute encephalitis as a complication of disease, and death. Cases were separated by age: younger than 1 year, 1-4 years, 5-9 years, 10-14 years, 15-19 years, and older than 20 years. Countries were also divided into categories based on their measles incidence per 100,000 inhabitants: zero (0), low (less than 0.1), moderate (0.1-1.0), and high (above 1).
The researchers found that, for the two years of the study, 12,132 cases of measles were recorded with most cases (10,239 / 85%) from the five countries above. Most cases were in unvaccinated or incompletely vaccinated children; however almost a fifth of cases were aged 20 years or older. Seven measles related deaths were recorded in these two years. Of the 210 cases that were reported as being 'imported', 117 (56%) came from another country within Europe and 43 (20%) from Asia.
Achievement and maintenance of the WHO-recommended minimum of 95% vaccination coverage with two doses is necessary for measles elimination. Suboptimum measles vaccination coverage over a long period has indeed been reported by countries with high measles incidence. Switzerland reported vaccination coverage of about 82% between 1991 and the beginning of this decade, with substantial variations among its 26 cantons. In the UK, measles vaccination coverage for children at 2 years of age was less than 90% (1999-2006), and was below 85% (2002-05), whereas in Ireland, coverage increased from less than 80% (1999-2003) to below 90% (2004-06). For the same age-group in Germany, vaccination coverage for children born between 1996 and 2003 was consistently around 70%, with substantial regional differences. In Italy, national vaccination coverage in children at 2 years of age increased from below 85% (2001-03) to below 90% (2004-2006), with large variations among regions. By contrast, co untries with zero indigenous measles incidence reported consistently high measles vaccination coverage for long periods. For example, in Finland, studies that have been undertaken every two years on birth cohorts from 1995 to 2003 showed that vaccination coverage was consistently above 95%.
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 Comment, Dr Jacques R Kremer and Dr Claude P Muller, WHO Regional Reference Laboratory for Measles and Rubella, Laboratoire National de Santé/CRP- Santé, Luxembourg, 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."
Dr Mark Muscat, Statens Serum Institut, Copenhagen, Denmark T) +45 3268 8254 E) mmc@ssi.dk
Dr Jacques R Kremer, WHO Regional Reference Laboratory for Measles and Rubella, Laboratoire National de Santé/CRP- Santé, Luxembourg T) +352-490604-241 E) Jacques.Kremer@lns.etat.lu
For full Article and Comment see: http://press.thelancet.com/measlesfinal.pdf
Notes to editors: *32 countries: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, UK.
Journal
The Lancet