Q&A on the DPRK measles outbreak campaign
Why did the outbreak of measles take place?
There was no reported case of measles in the recent years, and according to MoPH the last case of measles was diagnosed in 1992. Currently we have over 90 per cent coverage under measles vaccination in DPRK. However, during the period of the humanitarian crisis in the 90s, the coverage declined to less than 50 per cent. In the current outbreak of measles the majority of cases amounting to 40 per cent of the total are in the age group of - 11 and 19 years and this is the group that missed out the immunization during their infancy.
To prevent measles outbreaks countries need to include a second dose of measles in their immunization schedule. DPRK has only one dose of measles at 9 months of age in their schedule.
WHO analysed samples of serum and confirmed measles outbreak, however the source of virus is not yet identified.
Measles reduces the body’s defense against other infections during a few weeks. When measles occurs in a population that is already weakened due to malnutrition, it can be particularly deadly. Complications resulting from measles infection -can kill children or leave them with life long disabilities: blindness, deafness or brain damage. Of all the vaccine-preventable diseases, measles remains the leading cause of child deaths. Suffering, complications and death caused by measles can be easily prevented through immunization
How many people were affected?
Since the beginning of measles outbreak over 3600 people in 10 provinces of DPRK have been diagnosed, including two adults and two infants who died. Ryanggang province has the highest number of measles case in the country.
All measles cases were between 0 and 45 years, with the highest incidence among children under 1 year of age and between 11 and 19 years of age.
Was such a big campaign necessary?
Yes, this campaign was needed. The technical advice to undertake a campaign covering the entire vulnerable population was provided by the global experts in charge of combating measles in WHO and UNICEF headquarters.
The response could have been either to concentrate on the affected counties and provinces and respond to treatment of the cases or to undertake a campaign that can protect the whole population on a sustainable basis. By vaccinating most of the population in 2007, we accomplished to administer a second dose of measles nationwide. The new planned programmatic response to introduce a second dose of measles in the routine immunization schedule will prevent measles outbreaks in the future.
The campaign has helped in arresting the outbreak. Since the campaign no new measles cases have been reported.
What will be the impact of the campaign?
The measles campaign will immediately reduce measles incidence and avoid further future unnecessary suffering and mortality. Also, by going nationwide the measles campaign will vaccinate all remaining measles susceptible populations and provide DPRK with a fully protected population against measles. The government will now introduce a 2nd dose of measles in the routine immunization schedule, and consequently avoid future outbreaks.
Was the targeted age group correct?
Yes. All outbreak cases were between 0 and 45 years, with the highest incidence among children under 1 year of age and between 10 and 20 years of age. Vaccinating up to 45 will give almost 100% certainty of vaccinating and protecting all remaining measles susceptible persons in DPRK. However, one could argue that by not vaccinating the population between 40 and 45 (percentage of number of cases was only about 5% of all cases in the outbreak), the herd immunity from the rest of the population would protect this population in the future from catching measles.
What was the Mortality?
As the diagnosis measles was only confirmed in February 2007 and all cases before that date had been thought to be Rubella it is hard to know what the exact mortality number was. Measles causes immune suppression in the patient for 3-4 weeks. In that period common colds and diarrhea can suddenly become life threatening depending on the access to health and treatment.. . In any epidemic, mortality is higher at the end phase of the outbreak than at the beginning. Therefore, it is important to stop the outbreak as soon as possible.
What are the lessons learned?
The outbreak was diagnosed too late; however, the response was faster than any previous international outbreak
Outbreaks need to be laboratory confirmed immediately. Laboratories need to have the diagnostic kits available at all times and the technical knowledge to interpret them. 2500 cases and most mortality could have been avoided if the fever and rash outbreak had been confirmed to be measles. Vaccination could have been started at the end of December 2006. Therefore, the DPRK needs to further improve its surveillance. .
What should be the follow up to the campaign to establish a good measles programme with few to zero cases per year?
1) Continue the 1st dose of measles in the routine immunization schedule at 9 months for now. In a few years increase the age from 9 months to 12 months.