Effectiveness of Measures Against Influenza Outbreak at A Refuge Center After The Touhoku-Pacific Ocean Earthquake

Abstract

  After the Touhoku-Pacific Ocean Earthquake, an epidemic outbreak of influenza occurred in a gymnasium of a high school used as a refuge in Iwate. We report the time course of the outbreak and our intervention to prevent the infection spreading. A 60 years old woman with fever was diagnosed as influenza A first by rapid diagnosis kit on April 04, 2011. She had returned to the shelter after discharge from a regional hospital. Although quarantine treatment was started immediately using the empty classrooms, the number of patients with influenza increased every day. The patients were concentrated in a small area near the wall of the gymnasium, so we started oseltamivir prophylaxis administration according to the national insurance criteria on April 9. We also found that the dressing room next to the bathroom and the line for meals, where many people gathered in a small area, may have caused infection spreading. We checked the cleanliness of the dressing room and encouraged people to wear surgical masks in the line for meals. At the same time, we advised febrile patients to come to our temporary hospital immediately. The number of patients decreased after April 16, with no new cases after April 20, and no patient was isolated after April 24. Finally, the total number of influenza cases was 40. We were able to control the influenza outbreak to termination without experiencing severe cases. Immediate start of quarantine treatment, enforcing standard precautions, expanding the criteria for oseltamivir prophylaxis, and encouraging people with symptoms to go to our temporary hospital immediately, were considered to have contributed to the convergence of the outbreak.