High Incidence of Community-Acquired Pneumonia among Rapidly Aging Population in Japan: A Prospective Hospital-Based Surveillance

Abstract

SUMMARY:The age-group-specific incidence and etiological patterns of community-acquired pneumonia (CAP) have not been fully established in Japan. A 2-year prospective surveillance was conducted in Kochi city, Western Japan. All CAP patients aged AE15 years who visited a community-based hospital were enrolled in the study. Clinical samples were examined by conventional bacterial culture and urinary antigen tests, and 6 bacterial pathogens and 16 respiratory viruses were identified from sputum samples by multiplex polymerase chain reaction assays. The age-group-specific incidence of CAP was estimated using a population-based data set of the total number of outpatients in the whole city.

Community-Acquired Pneumonia in the Asia-Pacific Region

“…A prospective study in one Japanese city (Kochi) from May 2008 to April 2010 cited an incidence of 960 per 100,000 person years; 73.3% of cases were 65 years old. 10 More attention was given to the geriatric population in the latter study, in which annual incidence of CAP in older adults (75 years) was estimated to be 4,290 per 100,000. An Asian country that showed similar socioeconomic and ethnic characteristics to Japan would be South Korea.…”

“…13 Rudan et al conducted an estimation of the global incidence of childhood pneumonia, in which the annual incidences in Southeast Asia and Western Pacific regions were estimated to be 36,000 and 22,000 per 100,000 children, respectively. 18 When specific demographic groups were studied for CAP, a larger burden was almost always observed in older adults, 6,7,10,16,22 those residing in rural areas, [6][7][8]15 and minority ethnicity. 6,13 Most studies on the epidemiology of CAP in the Asia-Pacific region are from either nationwide mortality statistics or surveillance in geographically limited areas.…”

Distribution of the atypical pathogens of community-acquired pneumonia to disease severity

“…Demographic and clinical characteristics of 6,008 patients with community-acquired pneumonia in the study , denote those cases who had radiographic diagnosis of CAP, but no detailed radiographic findings provided in their questionnaires 4 ,. SFLRT indicates specimen obtained from lower respiratory tract, including eligible sputum, bronchoalveolar-lavage, endotracheal aspirate.…”

Pneumonia and Host Defense in the Elderly

“…Similarly, in Spain, the incidences were 9.9 (age 65 to 74 y), with rates almost 3-fold higher in those over the age of 85 years, 7 and in Japan, the incidence of pneumonia in those aged 65 to 74 years was over 3-fold higher than in the nonelderly, with a further 4-fold increase in those over the age of 75 years when compared with those in the age group of 65 to 74 years. 6 These findings are further highlighted in those residing in assisted living and nursing homes, where the incidence of pneumonia is 30-fold higher than in the general population and 11-fold higher than those over the age of 75 years and living independently. 8 Finally, to highlight the importance of pneumonia in the elderly, in the short period between 1997 and 2011, the incidence of pneumonia in those over 80 years increased >2-fold in Denmark.…”

“…4 Similar findings were observed worldwide in the United Kingdom, Spain, and Japan. [5][6][7] In the United Kingdom, incidence rates were 2 to 3/1000 in the age group of 65 to 69 years, whereas rates were B20/1000 in 85 to 89-year-old individuals. Similarly, in Spain, the incidences were 9.9 (age 65 to 74 y), with rates almost 3-fold higher in those over the age of 85 years, 7 and in Japan, the incidence of pneumonia in those aged 65 to 74 years was over 3-fold higher than in the nonelderly, with a further 4-fold increase in those over the age of 75 years when compared with those in the age group of 65 to 74 years.…”