Characteristics of infectious diseases in hospitalized patients during the early phase after the 2011 great east japan earthquake pneumonia as a signifi cant reason for hospital care

Background: Natural catastrophes increase infectious disease morbidity rates. On March 11, 2011, a 9.0-magnitude earthquake and associated Pacifi c coast tsunami struck East Japan. The aim of this study was to investigate the characteristics of patients with infectious diseases who needed hospitalization after this disaster. Methods: We searched the medical records of 1,577 patients admitted to Tohoku University Hospital in the Sendai area within 1 month (March 11, 2011-April 11, 2011) after the disaster. We examined (1) changes in the rates of hospitalizations for infectious diseases over time and (2) the variety of infectious diseases. Results: The number of hospitalized patients with infectious diseases increased after the fi rst week to double that during the same period in 2010. Pneumonia comprised 43% of cases, and 12% consisted of skin and subcutaneous tissue infection, including tetanus. Pneumonia was prevalent in elderly patients (median age, 78 years) with low levels of serum albumin and comorbid conditions, including brain and nervous system disorders. Sputum cultures contained Streptococcus pneumoniae, Moraxella catarrhalis , and Haemophilus influenzae , known pathogens of community-acquired pneumonia in Japan. In addition, 20.5% of patients had positive results for urinary pneumococcal antigen. Conclusions: Among hospitalized patients, infectious diseases were signifi cantly increased after the disaster compared with the same period in 2010, with pneumonia being prominent. The analyses suggest that taking appropriate measures for infectious diseases, including pneumonia, may be useful for disaster preparedness and medical response in the future.