TITLE:
Outbreak of Human Metapneumovirus in Ibaraki, Japan and Its Descriptive Epidemiology
AUTHORS:
Junko Kurita, Natsuki Nagasu, Noriko Nagata, Hideo Okuno, Tamie Sugawara, Yasushi Ohkusa
KEYWORDS:
Human Metapneumovirus, Infection Control Law, (Nursery) School Absenteeism Surveillance System, Surveillance
JOURNAL NAME:
Health,
Vol.10 No.6,
June
20,
2018
ABSTRACT: Introduction: The Infection Control Law in Japan does not cover monitoring of human metapneumovirus (HMPV). Therefore, its epidemiology is not well known. However, rapid diagnostic testing for this virus has been reimbursed by public health insurance in Japan since 2014. One case of acute encephalitis caused by HMPV was reported in April 2017 in Ibaraki. All schools in Ibaraki prefecture started to participate in the (Nursery) School Absenteeism Surveillance System ((N)SASSy) in 2009. All nursery schools started to use it in 2012. Methods: We specifically examine its seasonality and incidence by age. The study period extends from October 1, 2014 through May 31, 2017. Results: In total, (N)SASSy received 187 cases during the period. Spring and early summer were apparently the high season. The highest incidence was 36 cases in April 2015. The incidence among zero and one year olds was higher in 2017 than in the same season among 2014-2016. The necessary effort to download data from (N)SASSy, show these figures, and confirm the situation and background was a few minutes. Discussion: Rapid diagnostic testing for HMPV elucidated its epidemiology for the first time. Moreover, timely information sharing through (N)SASSy led the Ibaraki prefectural office to publish a reminder in July 2017 about the HMPV outbreak situation and to encourage precautions against it by nursery schools.