Mumps in the United Kingdom

Image credit: CDC/NIP/ Barbara RiceThe United Kingdom’s Department of Health Joint Committee on Vaccination and Immunization (JCVI) recently released the minutes from its latest meeting held in January. At that meeting, the committee discussed findings by its subcommittee on adolescent vaccinations regarding mumps in the United Kingdom, among other topics.1 The minutes record that the “sub-committee noted that a number of significant outbreaks of mumps had been seen in the UK over the last decade. Cases had been mainly limited to unimmunised and partially immunised individuals, however more recently a significant portion of infections were being confirmed in those who had received two MMR doses. However, generally mumps disease is less severe in immunised individuals.” (Emphasis added)

The concern of public health authorities in the UK is the waning of immunity against mumps in the 10 to 15 years after immunization. This decline comes just as teens and young adults are entering schools and universities where close contact is likely, triggering the outbreaks. The committee discussed several approaches to addressing the increase in mumps cases, including delaying the second dose of the MMR vaccine until adolescence, but that could leave young children without complete immunity to measles, which is currently epidemic in Europe.2 The committee concluded to recommend that physicians discuss vaccination status with adolescent patients and their parents and offer the MMR vaccine to those who are missing one or both doses.

These discussions on adolescent immunizations come as a result of an increase in the number of cases of vaccine-preventable diseases like mumps. In 1995, a total of 27 confirmed cases of mumps were reported to the UK public health system. In 2000, the number of confirmed cases reached 582. By 2005, confirmed mumps cases reached 3,901. For 2011, the year for which the most complete data are available, the number of confirmed cases was 2,871.3 The exact cause for this increase in cases has not been determined, but low vaccine uptake is suspected. For example, the UK MMR immunization rate reached 90% for the first time in over a decade only in 2010, and it was at its lowest in 2003 and 2004.4 The goal is to reach 95% vaccine uptake in order to achieve herd immunity against measles5 and 90% to achieve herd immunity against mumps.6

Until the MMR immunization rate climbs above 90% in the United Kingdom, the excess number of cases of mumps is likely to continue. Among those cases will be people who experience serious complications from the infection. For example, physicians in Ireland reported an increase in the number of cases of mumps orchitis,7 an inflammation of the testicles in adolescent and young adult men. This may lead to infertility or decreased fertility.8 According to the Mayo Clinic, rare or infrequent complications of mumps may include pancreatitis (inflammation of the pancreas), encephalitis (inflammation of the brain), meningitis (inflammation of the tissues covering the brain), hearing loss, and miscarriage if acquired early during pregnancy.9

FURTHER READING

Notes

1. JCVI sub-committee on adolescent vaccinations meeting: January …” 2012. 14 Aug. 2012 http://transparency.dh.gov.uk/2012/07/27/jcvi-sub-committee-on-adolescent-vaccinations-meeting-january-2012/

2. WHO: Europe must act on measles outbreak – Telegraph.  2011. 14 Aug. 2012 http://www.telegraph.co.uk/health/healthnews/8932117/WHO-Europe-must-act-on-measles-outbreak.html

3. HPA – Mumps notifications (confirmed cases), England and Wales … 2008. 14 Aug. 2012 http://www.hpa.org.uk/web/HPAweb&HPAwebStandard/HPAweb_C/1195733790975 

4. HPA – Measles cases surpass 2010 total but MMR vaccine uptake … 2011. 14 Aug. 2012 http://www.hpa.org.uk/NewsCentre/NationalPressReleases/2011PressReleases/110624Measlesstatement/

5. Cockman, P. Improving MMR vaccination rates: herd immunity is a realistic … – BMJ. 2011. http://www.bmj.com/content/343/bmj.d5703

6. Kutty, Preeta K et al. Seroprevalence of antibody to mumps virus in the US population, 1999–2004. Journal of Infectious Diseases 202.5 (2010): 667-674.

7. Davis, Niall F et al. The increasing incidence of mumps orchitis: a comprehensive review. BJU international 105.8 (2010): 1060-1065.

8. Orchitis: MedlinePlus Medical Encyclopedia. 2002. 14 Aug. 2012 http://www.nlm.nih.gov/medlineplus/ency/article/001280.htm

9. Mumps: Complications – MayoClinic.com. 2008. 14 Aug. 2012 http://www.mayoclinic.com/health/mumps/ds00125/dsection=complications