Measles outbreaks in the Kyeongin area of the Republic of Korea, 2013-2014: A single-center experience in a country of measles elimination

Abstract

Objective: To identify the source of infection and determine the clinical features and laboratory finding of measles infection. Methods: In 27 measles patients, except for 3 adult patients, the rest of 24 pediatric measles cases were analyzed with regard to age, sex, immunization status, transmission routes and molecular genotyping of measles virus. Eighteen measles patients who admitted in isolation ward were set apart to investigate clinical findings and its correlation with laboratory characteristics. Retrospective analysis of cases was conducted in this study. Results: Of the 24 pediatric patients, 23 (95.8%) had not received any measles-containing vaccine (MCV). Sixteen of the patients (66.7%) were aged <12 months. The suspicious index case of a girl aged 34 months was not vaccinated with MCV1 and got measles after a trip to Philippines, and molecular genotype was revealed as B3. Measles outbreaks in the community such as a restaurant were followed by this one imported case. According to analysis of 18 patients admitted in isolation ward, the median level of C-reactive protein (CRP) was 0.38 mg/dL and that of lactate dehydrogenase (LDH) was 1200 IU/L. All of the 18 patients had LDH levels above the normal range. Age correlated with CRP (Q = 0.528, P = 0.024) and LDH (Q = 0.501, P = 0.034). The duration of fever was correlated with the duration of fever before rash (Q = 0.898, P < 0.01). The duration of hospitalization was correlated with CRP (Q = 0.586, P = 0.011). The white blood cell counts were correlated with the levels of LDH (Q = 0.505, P 0.033), aspartate aminotransferase (Q = 0.507, P = 0.032), and alanine aminotransferase (Q = 0.481, P = 0.043). Conclusions: Early weaning of maternally derived measles antibodies therefore vaccination of MCV1 at a young age from 9 months to 12 months should be considered in situations of early exposure. Furthermore there is a call for consideration of scheduling an earlier age for the first dose of MMR vaccine in Europe. It is necessary for Korea to investigate the duration of the presence and quantitative analysis of maternal measles antibodies in infants and to reconsider the timing of MCV1.