Outbreak of measles in the Republic of Korea, 2007: importance of nosocomial transmission.
ABSTRACT From 2002 through 2006, Republic of Korea conducted extensive measles elimination activities and declared elimination in 2006. An outbreak of measles involving 180 confirmed cases occurred during 2007.
An outbreak investigation was performed and enhanced surveillance was implemented. Detailed case investigations and laboratory testing included serologic and molecular diagnostic methods. Cases were classified according to World Health Organization and national guidelines.
During 2007, 451 suspected cases were reported and 180 (40%) cases were confirmed as measles during epidemiologic weeks 14-42. Incidence during the outbreak was 3.7 cases per million persons, excluding imported cases. Most confirmed cases were reported from Seoul; 137 (76%) cases were among children <24 months old, 124 (69%) case patients had no history of measles vaccination, and 81 (45%) case patients resulted from nosocomial transmission in 6 hospitals. Community members, patients, and health care workers all contributed to measles virus transmission. Limited outbreak control measures were implemented; high population immunity likely accounted for the self-limited transmission during this outbreak.
Limited outbreaks of measles, in which nosocomial transmission can play an important role, may occur after countries have declared elimination. Timely and opportunistic vaccination may help prevent such outbreaks; high-quality surveillance is critical for their detection.
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ABSTRACT: Following the Five Year Measles Elimination Program, measles has been declared eliminated from the Republic of Korea since 2006. However, there remain challenges related to the surveillance of measles in the postelimination phase. Even though the routine surveillance system has revealed a gradual decrease in the number of reported cases since 2002, 4 resurgences have occurred, notably due to outbreaks. Because vaccine-modified measles is becoming widespread due to high vaccination coverage, conducting laboratory confirmation in each case becomes important. Moreover, susceptible individuals with measles have been identified through seroprevalence studies. Lastly, the efforts to improve the timeliness of measles reporting have led to the establishment of an active laboratory-based surveillance network, which has shortened the interval between diagnosis and notification. In these circumstances, searching for more sensitive and effective surveillance measures is important for maintaining the elimination status and preventing future outbreaks of measles in Korea.Korean Journal of Pediatrics 12/2012; 55(12):455-61.
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ABSTRACT: BACKGROUND: In this study, we modeled the cost benefit analysis for three different measles vaccination strategies based upon three different measles-containing vaccines in Korea, 2001. We employed an economic analysis model using vaccination coverage data and population-based measles surveillance data, along with available estimates of the costs for the different strategies. In addition, we have included analysis on benefit of reduction of complication by mumps and rubella. METHODS: We evaluated four different strategies: strategy 1, keep-up program with a second dose measles-mumps-rubella (MMR) vaccine at 4-6 years without catch-up campaign; strategy 2, additional catch-up campaign with measles (M) vaccine; strategy 3, catch-up campaign with measles-rubella (MR) vaccine; and strategy 4, catch-up campaign with MMR vaccine. The cost of vaccination included cost for vaccines, vaccination practices and other administrative expenses. The direct benefit of estimated using data from National Health Insurance Company, a government-operated system that reimburses all medical costs spent on designated illness in Korea. RESULTS: With the routine one-dose MMR vaccination program, we estimated a baseline of 178,560 measles cases over the 20 years; when the catch-up campaign with M, MR or MMR vaccines was conducted, we estimated the measles cases would decrease to 5936 cases. Among all strategies, the two-dose MMR keep-up program with MR catch-up campaign showed the highest benefit-cost ratio of 1.27 with a net benefit of 51.6 billion KRW. CONCLUSION: Across different vaccination strategies, our finding suggest that MR catch-up campaign in conjunction with two-dose MMR keep-up program was the most appropriate option in terms of economic costs and public health effects associated with measles elimination strategy in Korea.Vaccine 04/2013; · 3.77 Impact Factor
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ABSTRACT: Interruption of measles transmission was achieved in Catalonia (Spain) in 2000. Six years later, a measles outbreak occurred between August 2006 and June 2007 with 381 cases, 11 of whom were health care workers (HCW).The objective was to estimate susceptibility to measles in HCW and related demographic and occupational characteristics. A measles seroprevalence study was carried out in 639 HCW from six public tertiary hospitals and five primary healthcare areas. Antibodies were tested using the Vircell Measles ELISA IgG Kit. Data were analyzed according to age, sex, type of HCW, type of centre and vaccination history.The odds ratios (OR) and their 95%CI were calculated to determine the variables associated with antibody prevalence. OR were adjusted using logistic regression.Positive predictive values (PPV) and the 95% confidence intervals (CI) of having two documented doses of a measles containing vaccine (MCV) for the presence of measles antibodies and of reporting a history of measles infection were calculated. The prevalence of measles antibodies in HCW was 98% (95%CI 96.6-98.9), and was lower in HCW born in 1981 or later, after the introduction of systematic paediatric vaccination (94.4%; 95%CI 86.4-98.5) and higher in HCW born between 1965 and 1980 (99.0%; 95%CI 97.0-99.8). Significant differences were found for HCW born in 1965--1980 with respect to those born in 1981 and after (adjusted OR of 5.67; 95%CI: 1.24-25.91)A total of 187 HCW reported being vaccinated: the proportion of vaccinated HCW decreased with age. Of HCW who reported being vaccinated, vaccination was confirmed by the vaccination card in 49%. Vaccination with 2 doses was documented in only 50 HCW, of whom 48 had measles antibodies. 311 HCW reported a history of measles.The PPV of having received two documented doses of MCV was 96% (95%CI 86.3-99.5) and the PPV of reporting a history of measles was 98.7% (95%CI 96.7-99.6) CONCLUSIONS: Screening to detect HCW who lack presumptive evidence of immunity and vaccination with two doses of vaccine should be reinforced, especially in young workers, to minimize the risk of contracting measles and infecting the susceptible patients they care for.BMC Infectious Diseases 08/2013; 13(1):391. · 3.03 Impact Factor