Measles, which was once almost a youth’s `rite of passage’ in the United States, has been all but eliminated in recent years after the introduction of the first measles vaccine in 1963.
The chart below (source: CDC) shows the remarkable effectiveness of the vaccination campaign.
While many parents today think of measles as a relatively benign childhood illness, it actually produced significant morbidity and mortality with respiratory, ocular, and neurological complications - sometimes resulting in death.
During the 1950s – before the introduction of the measles vaccine – in the United States the disease infected roughly 4 million, hospitalized nearly 50,000, and contributed to the deaths of several hundred every year.
Admittedly, a vast improvement over the mortality rates from earlier in the century, when the disease was far deadlier (for reasons that quite frankly, remain hard to explain – Ian York explored this fascinating mystery in Measles week, part I: Introduction ).
But in recent years lower uptake of the vaccine – its reputation tainted by (disproven) claims of a possible link to autism (popularized by Dr. Andrew Wakefield and promoted by various anti-vaccination groups) – and the continual importation of the disease from countries where it remains endemic - have allowed the virus to keep a toehold in developed nations.
In developing countries, the incidence – and mortality rate – of measles remains high. These statistics from the World Health Organization:
Fact sheet N°286
- Measles is one of the leading causes of death among young children even though a safe and cost-effective vaccine is available.
- In 2008, there were 164 000 measles deaths globally – nearly 450 deaths every day or 18 deaths every hour.
- More than 95% of measles deaths occur in low-income countries with weak health infrastructures.
- Measles vaccination resulted in a 78% drop in measles deaths between 2000 and 2008 worldwide.
- In 2008, about 83% of the world's children received one dose of measles vaccine by their first birthday through routine health services – up from 72% in 2000.
Today news on measles from several fronts.
First, the WHO’s WER (Weekly Epidemiological Record) brings us details on an ongoing measles outbreak in Europe, that has infected more than 6,500 people in 33 nations.
As of 18 April 2011, 33 countries in Europe had reported 6500 measles cases. Epidemiological investigations and genotyping have confirmed transmission of measles virus among several countries in the Region and in the Americas.
In all these outbreaks, except for the second out-
break in Spain and the outbreak in Turkey, the D4
genotype of measles virus has been confirmed.
The B3 genotype of measles virus was isolated
from cases in the second measles outbreak in
Spain, while the D9 genotype, originating from
and common in south-east Asia (e.g. Malaysia and
Indonesia) was confirmed to have caused the out-
break in Istanbul (Turkey) in January 2011.
As you can see, there are a number of different strains or genotypes of measles. New ones emerge, or are detected, every so often. As of mid-2010, the World Health Organization (WHO) maintained reference strains representing 23 recognized genotypes.
From Eurosurveillance this week, a report on a novel strain of (an existing genotype:G3) of measles which has spread across Europe over a 2 month period.
Eurosurveillance, Volume 16, Issue 17, 28 April 2011
K E Brown, M N Mulders, F Freymuth, S Santibanez, M M Mosquera, S Cordey, J Beirnes, S Shulga, R Myers, D Featherstone
During late 2010, a previously unrecognised strain of measles genotype G3 virus was identified in five different European countries by the World Health Organization Measles and Rubella Laboratory Network. Apart from one, none had a travel history to south-east Asia, the usual source of G3 viruses, although epidemiological links could be established between some of the cases. This case series illustrates the value of genotyping and sequencing in tracking measles infections, and identifying otherwise unrecognised chains of transmission.
And next, from the Journal of Infectious Diseases a report on the impact of an outbreak of measles in Tucson, Arizona in 2008 that affected two healthcare facilities.
J Infect Dis. (2011) jir115 first published online April 28, 2011 doi:10.1093/infdis/jir115
Sanny Y. Chen,
Shoana Anderson, Preeta K. Kutty, Francelli Lugo, Michelle McDonald, Paul A. Rota, Ismael R. Ortega-Sanchez, Ken Komatsu, Gregory L. Armstrong, Rebecca Sunenshine, and Jane F. Seward
You can follow the above link to read the entire article, or for the short version, you can read the press release from the IDSA.
[EMBARGOED FOR APRIL 29, 2011] The U.S. measles vaccination program has been successful in eliminating endemic measles in the United States; yet this success has provided challenges that require ongoing vigilance for the rapid identification and response to measles cases in health care settings. In 2008, the largest reported health care-associated measles outbreak in the United States since 1989 occurred in Tucson, Arizona, costing approximately $800,000 in response and containment efforts. In a report published in The Journal of Infectious Diseases and available online, researchers identify preventive measures hospitals and health care facilities can implement to reduce the likelihood and decrease the economic impact of a future measles outbreak in these settings.
Due to a highly effective vaccine and high vaccine coverage, measles was declared eliminated in the United States in 2000; however, the potential for measles infection still exists in this country. Non-adherence to U.S. vaccination recommendations and infection among unvaccinated travelers coming into the United States continue to pose potential threats to the public and to health care personnel. In the 2008 Tucson outbreak, an unvaccinated, infected Swiss traveler visited a hospital emergency department on February 12. The traveler was admitted to the hospital the next day, but a measles diagnosis was not confirmed until February 20. This ignited an intense and lengthy public health investigation and response to persons with suspected and confirmed measles as well as contacts of those persons.
And again from the Journal of Infectious diseases, an editorial comment on the above study by Stephen M. Ostroff.
The full text of both articles is freely available.
Stephen M. Ostroff
J Infect Dis. (2011) jir125 first published online April 28, 2011 doi:10.1093/infdis/jir125
While not the scourge of the early 20th century in the United States, measles remains a serious public health threat in much of the world, and is only held at bay in developed countries by relatively high vaccination rates.