Article in Japanese

Measles outbreak among infants and toddlers originated from an unvaccinated child

Hiroyuki SHIMIZU^1,2), Asuka EDA³⁾, Kimi KATAYAMA⁴⁾, Yayoiko ANAN⁴⁾, Rieko SUZUKI⁵⁾, Tomohiko TAKASAKI⁵⁾

We experienced a measles outbreak of 8 patients most of whom are children in Fujisawa City, Kanagawa prefecture in March 2019. The index case was a 2-year-old girl who was healthy and had no overseas travel history. She had not received any vaccination due to her parents' creed. Before the outbreak ended, 620 people had come into contact with persons who developed measles at the pediatric clinic she visited until the diagnosis was confirmed and her nursery school. Eventually, 5 of those contacted had secondary infections: 3 of them at the nursery school and 2 of them at the pediatric clinic. Third infections occurred in one person at the pediatric clinic and in one family member of a secondary-infected child in the same household. Of the 8 who developed the disease, 4 were unvaccinated and the other 4 were vaccinated once. Those who received vaccination twice or more did not developed the disease. One of the unvaccinated received an urgent vaccine after being exposed, but developed the disease. We declared early termination of the outbreak as a result of our quick initial response and close cooperation among the hospital, the public health center, and the pediatric clinic.

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1) Department of Clinical Laboratory Medicine, Fujisawa City Hospital
2) Infection Control Team, Fujisawa City Hospital
3) Karugamo Fujisawa Clinic
4) Fujisawa Public Health Center
5) Kanagawa Prefectural Institute of Public Health

Key words	measles, vaccine, modified measles, PCR, vaccine hesitancy
Received	September 5, 2019
Accepted	December 28, 2019

32 (1)：39─44,2020