According to a study in The Lancet , WHO members made it their goal to reduce measle mortality rates by 90% before 2010. However, the authors, from Penn State University, demonstrate that measles mortality has fallen only 74%.
The study, by Dr Peter Strebel from the Department of Immunization, Vaccines and Biologicals at the WHO in Switzerland and his team, which is published to coincide with WHO’s World Immunization Week, shows that according to a 2007 report, the global goal to reduce measles deaths by 50% from 1999 by 2005 had been achieved.
After the achievement, WHO members then agreed to pursue the even more ambitious target of a 90% reduction between 2000 and 2010. In 2002, in the Americas endemic transmission of measles virus was interrupted, with four of the remaining five WHO regions, i.e. all except Southeast Asia having set target dates to eliminate measles by 2020 or earlier.
To evaluate the global measles progress towards the 2010 reduction goal, the researchers designed a new model, which in comparison with other models, objectively uses surveillance data to estimate both incidence and the age distribution of cases, accounts for herd immunity, and uses robust statistical methods to estimate levels of uncertainty.
Estimations show that the global measles mortality dropped by 74% from 535,300 deaths in 2000 to 139,300 in 2010, in over three-quarters of all WHO regions, with the exception of the WHO Southeast Asia Region.
India’s measles mortality in 2010 was 47%, with 36% in the WHO African region, 8% in southeast Asia excluding India, 7% in the Eastern Mediterranean Region 7%, 2% in the Western Pacific Region and less than 1% in the Americas and Europe respectively.
According to the researchers, India’s relatively low measles vaccine coverage of only 74%, which is even lower than the 76% coverage in Africa, is the reason for the fact that measles remains a major cause of mortality in the country. The coverage in Southeast Asia excluding India in 2010 was 79%, 85% in the Eastern Mediterranean, 93% in the Americas with 95% in Europe and 97% in the Western Pacific region, whilst the overall global coverage for measles vaccination was 85%. The key driver behind the gigantic drop in mortality were the more than 1 billion doses of measles vaccine that were administered by supplementary mass vaccination campaigns in the last decade.
In a concluding statement the researchers say:
“Despite rapid progress in measles control from 2000 to 2007, delayed implementation of accelerated disease control in India and continued outbreaks in Africa stalled momentum towards the 2010 global measles mortality reduction goal. Intensified control measures and renewed political and financial commitment are needed to achieve mortality reduction targets and lay the foundation for future global eradication of measles.”
Dr Walter A. Orenstein from the School of Medicine and Emory Vaccine Center at Emory University in Atlanta, GA, USA and Dr Alan R. Hinman, from the Center for Vaccine Equity at the Task Force for Global Health in Decatur, GA, USA, say in a linked comment:
“Measles eradication is biologically feasible and while no formal eradication goal has yet been set, progress on the mortality reduction goal will lead to consideration for an eradication goal. This paper highlights critical gaps in available data to guide prevention programs; surveillance and vital record registrations are inadequate in much of the world. What is most needed is not more sophisticated ways to estimate mortality, but to measure mortality directly. As measles is considered for eradication, it will be critical to improve surveillance to the point that deaths and cases will actually be measured, not estimated.”
Written By Petra Rattue