619. Post-tsunami outbreaks of influenza in evacuation centers in Miyagi prefecture, Japan, 2011
Session: Poster Abstract Session: Outbreak Investigation
Friday, October 21, 2011
Room: Poster Hall B1
Background: Miyagi prefecture in Japan was the area most severely devastated by the tsunami of 11 March 2011, with extensive loss of lives and property. There has been at least 8,000 deaths and more than 6,000 missing persons, while hundreds of thousands of people have lost their houses and been forced to move to evacuation areas. In the aftermath of the tsunami disaster, transmission of infectious diseases in evacuation centers was a concern, because of several factors including overcrowding, poor hand hygiene due to disrupted water supply, and breakdown of the public health system.

Methods: We experienced two outbreaks of influenza at crowed evacuation centers in Miyagi prefecture at March to April. The first outbreak occurred at a large-scale evacuation center in Kesennuma, with 25 patients diagnosed as influenza. The second one occurred at a middle-scale center in Natori, with 16 patients. More than half of cases were diagnosed as influenza A by rapid antigen tests, however the rest of them were clinically diagnosed.

Results: Several measures to control the outbreaks were taken. Hand hygiene with hand sanitizers and cough etiquette were strongly promoted, using posters and stickers. Bottles of alcohol-based hand sanitizers were installed in the centers, and face masks were distributed to refugees. Symptomatic patients were kept at isolation rooms in evacuation centers until 2 days after the resolution of fever. Individuals including the family members who were seated within 1 or 2 meter from the symptomatic patients were closely monitored whether they might develop symptoms later. Post-exposure chemoprophylaxis was conducted against high risk persons who had close contact with confirmed or suspected cases. In the former evacuation center, a medical examination room for febrile patients was set up aside from a general medical office.

As a result of control measures, both of outbreaks subsided without any complicated or fatal cases of influenza. 

Conclusion: It is important to adopt bundles of control measures promptly against outbreaks in the settings of evacuation centers after disasters like in hospital settings.

Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

Masumitsu Hatta, MD, PhD1, Shiro Endo, MD, PhD1, Koichi Tokuda, MD, PhD, MPH1, Hiroyuki Kunishima, MD, PhD2, Kazuaki Arai, ICMT, PhD3, Hisakazu Yano, MD, PhD3, Noriomi Ishibashi, MD1, Tetsuji Aoyagi, MD, PhD1, Mitsuhiro Yamada, MD, PhD2, Shinya Inomata, MD1, Hajime Kanamori, MD, PhD1, Yoshiaki Gu, MD, MPH2, Miho Kitagawa1, Yoichi Hirakata, MD, PhD3 and Mitsuo Kaku, MD, PhD1, (1)Department of Infection Control and Laboratory Diagnostics, Tohoku University Graduate School of Medicine, Sendai, Japan, (2)Department of Regional Cooperation for Infectious Diseases, Tohoku University Graduate School of Medicine, Sendai, Japan, (3)Department of Clinical Microbiology with Epidemiological Research & Management and Analysis of Infectious Diseases , Tohoku University Graduate School of Medicine, Sendai, Japan


M. Hatta, None

S. Endo, None

K. Tokuda, None

H. Kunishima, None

K. Arai, None

H. Yano, None

N. Ishibashi, None

T. Aoyagi, None

M. Yamada, None

S. Inomata, None

H. Kanamori, None

Y. Gu, None

M. Kitagawa, None

Y. Hirakata, None

M. Kaku, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.