Abstract & Commentary

European measles outbreaks continue: Past gains lost to vaccine objections

By Stan Deresinski, MD, FACP, FIDSA, Clinical Professor of Medicine, Stanford University, Associate Chief of Infectious Diseases, Santa Clara Valley Medical Center, is Editor for Infectious Disease Alert.

Source: Centers for Disease Control and Prevention (CDC). Increased transmission and outbreaks of measles - European region, 2011. MMWR Morb Mortal Wkly Rep 2011:60:1605-1610.

The importation of measles into the U.S. was discussed in these pages earlier this year1. Europe was the Source of a number of cases and it was pointed out that between 2005 and 2008, almost 2 of 5 imported cases were the result of exposure to the virus in that region of the world. The significant progress toward the World Health Organization goal of elimination of measles in the European zone that had been made during 2003-2008 has, unfortunately, been reversed and increased transmissions, often in outbreak settings, have become widespread. A total of 115 outbreaks were reported by 36 of 53 European Region member states so far in 2011. As of October 26, a total of 26,074 cases of measles had been reported, with France accounting for more than half. One-fourth of cases occurred in children <5 years of age, another fourth in those 5-14 years, and one-half in those >15 years of age. The vaccination status was unknown for 45.4% while 45.1% were known to not have been vaccinated. Nine measles-associated deaths were reported, including 6 in France, where national coverage with a single dose of a measles-containing vaccine was only 87%-90% during 2004-2010. This vaccination rate may be compared to the 90%-92% coverage of the region as a whole. Unfortunately vaccination rates <95% can support continuing transmission and lead to large outbreaks such as those being experienced in the European zone.

Commentary

The settings in which transmission occurred included, in addition to the general community, groups with religious or philosophical objections to vaccination, underserved populations with limited healthcare access, health-care facilities, and schools. Within specific countries, outbreak settings also included vacation camps in France and rural populations in Romania. Fourteen cases of measles in healthcare providers at public hospitals in Marseilles, France, were identified between April and November 2010 with 12 of the cases believed to have been acquired in the hospital setting2. Six of the providers had never been vaccinated and 4 had received only a single dose of vaccine during childhood.

The reasons for the inadequate vaccination rates in the European zone include lack of knowledge regarding the seriousness of measles infection, public skepticism about the benefits and safety of vaccines, and, in some cases, limited access to healthcare. A growing problem, particularly in western Europe, is that of religious and philosophical objections to vaccination. While Europe is the Source of a large proportion of measles cases imported into the U.S., other countries also pose a risk. Within Africa, Nigeria and Somalia have each had >15,000 cases in the last year and Congo has had >100,000. It is clearly important that, in addition to adhering to current recommendations for measles vaccination for the general population, attention be focused on measles associated with international travel. Thus, U.S. residents traveling abroad should be fully vaccinated. While children ordinarily receive their first dose of MMR or MMRV at 12 months of age, MMR should be administered to children as young as 6 months who are traveling internationally. Mass gatherings provide a significant risk for large outbreaks. For instance, The UEFA European Football Championship tournament begin 8 June 2012 in Poland and Ukraine with the championship game on July 1. The 2008 series, held in Austria and Switzerland, drew an average attendance of 38,803 per match and a total attendance of 1,140,902. The potential for outbreaks is obvious.

Finally, clinicians must remain alert to the manifestations of measles in order to rapidly diagnose cases and thus reduce the risk of further transmissions.

References

  1. Deresinski S. Measles – It's Back. Infect Dis Alert 2011;30:Issue 9,June: 97-98.
  2. Botelho-Nevers E, et al. Measles among healthcare workers: a potential for nosocomial outbreaks. Euro Surveill 2011 Jan 13;16(2). pii:19764.