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Geriatr Gerontol Int 2015; 15: 417–421
ORIGINAL ARTICLE: EPIDEMIOLOGY, CLINICAL PRACTICE AND HEALTH
Relationship between oral bacteria count and pneumonia onset in elderly nursing home residents Takeshi Kikutani,1,2 Fumiyo Tamura,1 Haruki Tashiro,2 Mitsuyoshi Yoshida,3 Kiyoshi Konishi4 and Ryo Hamada5 1
Division of Clinical Oral Rehabilitation, The Nippon Dental University Graduate School of Life Dentistry at Tokyo, 4Department of Microbiology, The Nippon Dental University School of Life Dentistry at Tokyo, 2Division of Rehabilitation for Speech and Swallowing Disorders, Nippon Dental University Tama Oral Rehabilitation Clinic, 3Dental Department, Hiroshima City General Rehabilitation Center, Hiroshima, and 5Incubation Center Panasonic Healthcare Co., Ltd., Tokyo, Japan
Aim: Oral bacteria, which are a source of infection for aspiration pneumonia, were examined in frail older adults with the aim of establishing a standard bacteria count that indicates the risk of pneumonia onset in this group. Methods: A survey of bacteria count in the saliva using a simple instrument for measurement of the number of oral bacteria, along with factors including swallowing function and nutritional status, was carried out in 691 elderly individuals requiring care (137 men; mean age 82.6 ± 8.3 years; 554 women; mean age 88.0 ± 7.1 years; total mean age 86.7 ± 7.8 years) at 16 nursing homes in Japan. All participants gave their consent for inclusion in the present study. During a 6-month follow-up period, participants who developed pneumonia were identified, and relationships between the factors measured at the start of the period and pneumonia onset were examined. Results: During the 6-month follow-up period, 33 participants (4.8%; 5 men, 28 women; mean age 88.3 ± 7.4 years) developed pneumonia. Pneumonia onset was significantly associated with reduced activities of daily living, swallowing dysfunction and undernourishment. Logistic regression analysis identified a saliva bacteria count of 108.5 colony-forming units/mL as an independent explanatory factor for pneumonia onset (P = 0.012, RR = 3.759). Conclusions: Oral bacteria count of 108.5 colony-forming units/mL saliva in an elderly person requiring care was identified as a risk factor for pneumonia onset. Geriatr Gerontol Int 2015; 15: 417–421. Keywords: aspiration pneumonia, oral bacteria count, oral health care.
Introduction Older adults are known to have a high incidence of aspiration pneumonia, and this is believed to be associated with intraoral bacteria infection.1 Many bacteria that are specific causative agents of pneumonia are present in the oral cavity,2 and it is difficult to selectively reduce the number of pneumonia-causing bacteria. Oral care can lead to favorable changes in the composition and abundance of oral bacteria,3,4 and it has been reported that specialist oral care can reduce
Accepted for publication 17 February 2014. Correspondence: Professor Takeshi Kikutani DDS PhD, Division of Rehabilitation for Speech and Swallowing Disorders, Nippon Dental University Tama Oral Rehabilitation Clinic, 4-44-19 Higashi, Koganei-shi, Tokyo 184-0011, Japan. Email: [email protected]
© 2014 Japan Geriatrics Society
the number of days of fever and the frequency of pneumonia onset,5,6 as well as reduce the mortality rate from pneumonia.7 Terpenning et al. discussed the economic effectiveness of carrying out oral care in these cases, and also calculated the cost of oral care in terms of human resources.8 They found that oral care is highly effective. We determined the oral bacteria count in older adults requiring care using a simple instrument recently developed for the measurement of the number of oral bacteria,9,10 and investigated the relationship between the oral bacteria count and subsequent pneumonia onset. We then used these findings to identify individuals at high risk of pneumonia onset. We expect that this type of screening program will enable the implementation of intensive oral care for high-risk individuals and will contribute to the prevention of aspiration pneumonia onset, which is significant from the perspective of medical economics. doi: 10.1111/ggi.12286
| 417
T Kikutani et al.
The present study focused on the number of oral bacteria, which are a source of infection in aspiration pneumonia, with the aim of establishing a standard oral bacteria count for assessing the risk of pneumonia onset.
Methods
Xerostomia The presence or absence of xerostomia was assessed according to the following categories reported by Kakinoki et al.: dry, mildly dry, wet (normal) and wet (high).12 Dry and mildly dry categories indicate the presence of xerostomia.
Participants
Activities of daily living
The survey was carried out in 691 older adults requiring care (137 men; mean age 82.6 ± 8.3 years; 554 women; mean age 88.0 ± 7.1 years; total mean age 86.7 ± 7.8 years) at 16 nursing homes in Japan who gave their consent to participate in the present study. We explained the purpose and procedure of the study to the participants both orally and in writing, and we obtained written informed consent from all participants or their families. The study was approved by the ethics committee of The Nippon Dental University, School of Life Dentistry at Tokyo.
Evaluation of activities of daily living was carried out using the Barthel Index 1.13
Survey of aspiration pneumonia The follow-up period was 6 months, and onset of aspiration pneumonia during this period was assessed. Pneumonia was diagnosed by each participant’s primary physician. Criteria for diagnosis of pneumonia were a new pulmonary infiltrate seen on a chest radiograph and one of the following features: cough, temperature greater than 37.5°C or subjective dyspnea.
Bacteria count Oral bacteria count was determined using saliva collected from the sublingual area within 30 min of waking. To obtain a specimen, we rinsed a cotton swab in saliva in the floor of the oral cavity for 10 s. Participants were not permitted to eat or drink between waking and saliva collection. Bacteria were enumerated using a simple instrument for the measurement of the number of oral bacteria developed by Hamada et al.9 and Kikutani et al.,10 and counts were stratified into the following categories (colony-forming units [CFU]/mL):
Geriatr Gerontol Int 2015; 15: 417–421
ORIGINAL ARTICLE: EPIDEMIOLOGY, CLINICAL PRACTICE AND HEALTH
Relationship between oral bacteria count and pneumonia onset in elderly nursing home residents Takeshi Kikutani,1,2 Fumiyo Tamura,1 Haruki Tashiro,2 Mitsuyoshi Yoshida,3 Kiyoshi Konishi4 and Ryo Hamada5 1
Division of Clinical Oral Rehabilitation, The Nippon Dental University Graduate School of Life Dentistry at Tokyo, 4Department of Microbiology, The Nippon Dental University School of Life Dentistry at Tokyo, 2Division of Rehabilitation for Speech and Swallowing Disorders, Nippon Dental University Tama Oral Rehabilitation Clinic, 3Dental Department, Hiroshima City General Rehabilitation Center, Hiroshima, and 5Incubation Center Panasonic Healthcare Co., Ltd., Tokyo, Japan
Aim: Oral bacteria, which are a source of infection for aspiration pneumonia, were examined in frail older adults with the aim of establishing a standard bacteria count that indicates the risk of pneumonia onset in this group. Methods: A survey of bacteria count in the saliva using a simple instrument for measurement of the number of oral bacteria, along with factors including swallowing function and nutritional status, was carried out in 691 elderly individuals requiring care (137 men; mean age 82.6 ± 8.3 years; 554 women; mean age 88.0 ± 7.1 years; total mean age 86.7 ± 7.8 years) at 16 nursing homes in Japan. All participants gave their consent for inclusion in the present study. During a 6-month follow-up period, participants who developed pneumonia were identified, and relationships between the factors measured at the start of the period and pneumonia onset were examined. Results: During the 6-month follow-up period, 33 participants (4.8%; 5 men, 28 women; mean age 88.3 ± 7.4 years) developed pneumonia. Pneumonia onset was significantly associated with reduced activities of daily living, swallowing dysfunction and undernourishment. Logistic regression analysis identified a saliva bacteria count of 108.5 colony-forming units/mL as an independent explanatory factor for pneumonia onset (P = 0.012, RR = 3.759). Conclusions: Oral bacteria count of 108.5 colony-forming units/mL saliva in an elderly person requiring care was identified as a risk factor for pneumonia onset. Geriatr Gerontol Int 2015; 15: 417–421. Keywords: aspiration pneumonia, oral bacteria count, oral health care.
Introduction Older adults are known to have a high incidence of aspiration pneumonia, and this is believed to be associated with intraoral bacteria infection.1 Many bacteria that are specific causative agents of pneumonia are present in the oral cavity,2 and it is difficult to selectively reduce the number of pneumonia-causing bacteria. Oral care can lead to favorable changes in the composition and abundance of oral bacteria,3,4 and it has been reported that specialist oral care can reduce
Accepted for publication 17 February 2014. Correspondence: Professor Takeshi Kikutani DDS PhD, Division of Rehabilitation for Speech and Swallowing Disorders, Nippon Dental University Tama Oral Rehabilitation Clinic, 4-44-19 Higashi, Koganei-shi, Tokyo 184-0011, Japan. Email: [email protected]
© 2014 Japan Geriatrics Society
the number of days of fever and the frequency of pneumonia onset,5,6 as well as reduce the mortality rate from pneumonia.7 Terpenning et al. discussed the economic effectiveness of carrying out oral care in these cases, and also calculated the cost of oral care in terms of human resources.8 They found that oral care is highly effective. We determined the oral bacteria count in older adults requiring care using a simple instrument recently developed for the measurement of the number of oral bacteria,9,10 and investigated the relationship between the oral bacteria count and subsequent pneumonia onset. We then used these findings to identify individuals at high risk of pneumonia onset. We expect that this type of screening program will enable the implementation of intensive oral care for high-risk individuals and will contribute to the prevention of aspiration pneumonia onset, which is significant from the perspective of medical economics. doi: 10.1111/ggi.12286
| 417
T Kikutani et al.
The present study focused on the number of oral bacteria, which are a source of infection in aspiration pneumonia, with the aim of establishing a standard oral bacteria count for assessing the risk of pneumonia onset.
Methods
Xerostomia The presence or absence of xerostomia was assessed according to the following categories reported by Kakinoki et al.: dry, mildly dry, wet (normal) and wet (high).12 Dry and mildly dry categories indicate the presence of xerostomia.
Participants
Activities of daily living
The survey was carried out in 691 older adults requiring care (137 men; mean age 82.6 ± 8.3 years; 554 women; mean age 88.0 ± 7.1 years; total mean age 86.7 ± 7.8 years) at 16 nursing homes in Japan who gave their consent to participate in the present study. We explained the purpose and procedure of the study to the participants both orally and in writing, and we obtained written informed consent from all participants or their families. The study was approved by the ethics committee of The Nippon Dental University, School of Life Dentistry at Tokyo.
Evaluation of activities of daily living was carried out using the Barthel Index 1.13
Survey of aspiration pneumonia The follow-up period was 6 months, and onset of aspiration pneumonia during this period was assessed. Pneumonia was diagnosed by each participant’s primary physician. Criteria for diagnosis of pneumonia were a new pulmonary infiltrate seen on a chest radiograph and one of the following features: cough, temperature greater than 37.5°C or subjective dyspnea.
Bacteria count Oral bacteria count was determined using saliva collected from the sublingual area within 30 min of waking. To obtain a specimen, we rinsed a cotton swab in saliva in the floor of the oral cavity for 10 s. Participants were not permitted to eat or drink between waking and saliva collection. Bacteria were enumerated using a simple instrument for the measurement of the number of oral bacteria developed by Hamada et al.9 and Kikutani et al.,10 and counts were stratified into the following categories (colony-forming units [CFU]/mL):
