Epidemiological Characteristics of Measles Outbreakin 2000~2001, Korea

Lee, Ho Dong; Bae, Geun Ryang; Lee, Ju Young; Kim, So Jin; Go, Un Yeong; Yang, Byung Guk; Lee, Jong Gu; Kim, Moon Shik

Abstract

BACKGROUND: In 2000~2001 there was a nationwide outbreak of measles in the Republic of Korea. Since supplementary vaccination program was implemented in 2001, the control strategy of this measles outbreak has been stepped up from the control phase to the elimination phase. We here present the result of survey for the epidemiologic characteristics of the nationwide outbreak of measles in 2000~2001.
METHODS
Using the data based on the sheet of epidemiologic investigation, incidences rates per 100,000 population and distributions of cases with vaccination history were investigated by the age. The seasonal or regional distribution were also studied with the onset days of cases.
RESULTS
In 2000~2001, a measles outbreak occurred with 52,897 reported cases. The incidence rate per 100,000 population of measles was 111.9 cases and that of geopolitical unit (province) was high nationwide, 35.9~386.3 cases. The incidence rates were very high in less than 12 months and 10 years of age, 954.4 and 714.9, respectively. The 1st vaccination rate of measles/mumps/rubella (MMR) in 1~3 years old was 26.3~77.1%, and especially, that of 1 year old showed very low coverage, 26.3%. However, there was no special propensity in the 1st vaccine coverage in the age of 7~15 years, which had 87.7~91.4%. On the other hand, the 2nd MMR vaccination rate of the cases was very low, 17.7% at the age of 7~10 years. From the 21st May, 2001 a mass catch-up campaign with measles/rubella (MR) vaccine was launched, resulting in prominent reduction in the incidence of measles case.
CONCLUSION
This survey showed that the measles outbreak in 2000~2001 had a high incidence nationwide from October 2000 to April 2001 and in less than 12 month and 10 years of age. Our results also showed that no routine immunization made the age group under 1 year vulnerable to measles infection. In cases of school-age group after 7 years of age, some cases with vaccination history were also infected. The characteristics of recent outbreaks indicates the need for the introduction of a specific vaccination programme at that age group. This survey was helpful to establish the effective vaccination strategy and it would be used as reference data on survey continuously for the epidemiologic characteristics of measles case for elimination of indigenous measles transmission in Republic of Korea.