Clinical analysis of pneumonia in the elderly in a community hospital--comparison of community-acquired pneumonia and nosocomial pneumonia]

We experienced 530 elderly cases with pneumonia among 930 patients with pneumonia in Kawasaki Medical School Kawasaki Hospital between April 1986 and September 1998. Clinical analysis of all these patients and a comparison of one group consisting of 418 patients with community-acquired pneumonia and another group composed of 112 patients with nosocomial pneumonia were performed. In all of the elderly patients with pneumonia, respiratory symptoms and inflammatory findings were less frequent, but were frequent for those in poor general and nutritional condition. The causative microorganism was isolated in 42% of these patients. Streptococcus pneumoniae, MSSA and Klebsiella pneumoniae were frequently isolated from the sputum of the patients with community-acquired pneumonia, while Methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Methicillin-sensitive Staphylococcus aureus (MSSA) were frequently isolated from that of nosocomial pneumonia patients. Mycoplasma pneumoniae, Chlamydia pneumoniae and some viruses were less frequent for patients in both groups. Although many intravenous antibiotics, such as cephem or carbapenem were administered to patients in both groups, the prognosis was relatively good for those with community acquired pneumonia but was extremely poor for those with nosocomial pneumonia despite mechanical ventilation or steroid pulse therapy for many patients.     

Clinical analysis of community-acquired pneumonia and pulmonary tuberculosis in the elderly and advances in treatment]

We treated 510 elderly case (over 65 years old) among 1,017 patients with community-acquired pneumonia and 60 similar cases among 112 patients with pulmonary tuberculosis in Kawasaki Medical School Kawasaki Hospital during approximately the past 15 years. These were compared with non-elderly cases (below 65 years old). In the elderly cases with community-acquired pneumonia, atypical clinical symptoms or physical signs were frequent and the mortality rate was high because of severe underlying diseases, and poor general and nutritional conditions. Regarding a prospective study of 84 elderly cases with community-acquired pneumonia during the past two years, S. pneumoniae, Respiratory virus, Gram-negative bacilli, H. influenzae, M. Tuberculosis were frequently isolated. In addition, mixed viral and bacterial infections, which were frequently noted during the winter, were significantly related to the increased frequency of community-acquired pneumonia. In treating elderly cases with community-acquired pneumonia, immunization therapy (e.g., influenza vaccine), second cephalosporin and/or macrolide antimicrobial agents for outpatients with mild pneumonia, and carbapenem and/or macrolide antimicrobial agents for hospitalized patients with moderate or severe pneumonia were most effective. The number of elderly cases with pulmonary tuberculosis has recently increased and the recognition of 10 cases was delayed because of a low percentage of positive smears, but no resistance to antituberculosis drugs have been observed. Regarding the treatment of pulmonary tuberculosis, fluoroquinolone and rifamycin derivative antibiotics have been developed as antituberculosis drugs with strong antituberculous activity. However, due to the high percentage of adverse effects in elderly patients, careful treatment with desensitization therapy for antituberculosis drugs is considered important.     

Clinical analysis of community-acquired pneumonia requiring hospitalization in a community hospital--comparison of elderly and non-elderly patients

A comparative study of 890 patients with community-acquired pneumonia requiring hospitalization in a community hospital was performed. The patients were divided into an elderly patient group and a non-elderly patient group. The elderly patients with community-acquired pneumonia exhibited frequent atypical symptoms such as dyspnea, consciousness disturbance and complication of shock, and also were frequently in a poor nutritional condition. The causative microorganism was isolated in 40.8% of the elderly patients and in 44.0% of the non-elderly patients. Polymicrobial agents were detected frequently in the elderly patients. Streptococcus pneumoniae (19.4%), MSSA (16.8%), Klebsiella pneumoniae (15.1%) and Haemophilus influenzae (15.0%) were frequently isolated from the sputum of the elderly patients, while Mycoplasma pneumoniae (25.2%), H. influenzae (15.0%), S. pneumoniae (12.2%) and MSSA (10.2%) were frequently isolated from that of the non-elderly patients. Regarding treatment with antibiotics, therapy with a single antibiotic therapy, such as cephem or carbapenem was carried out for the elderly patients, while new quinolone or tetracycline was administered to the non-elderly patients. Although the treatment with antibiotics was adequate according to the guidelines of the American Thoracic Society, the prognosis was poor; i.e.) in the elderly patients an efficacy rate of 74.3% and a mortality rate of 9.5%. In the non-elderly patients, the prognosis was good; i.e.) an efficacy rate of 88.0% and a mortality rate of 1.7%. These results suggest that the most important factors affecting the prognosis were the general condition of elderly patients and delay in an adequate diagnosis and treatment because of atypical clinical findings.     

Clinical analysis of patients with community-acquired pneumonia caused by a mixed infection of polymicrobial agents--including a comparative study of an infectious group with monomicrobial agents and an infectious group with unknown agents

We clinically analyzed 83 patients with community-acquired pneumonia caused by a mixed infection of polymicrobial agents who we have treated during the past 15 years. A comparative study among three groups; an infectious group with polymicrobial agents (83 cases), an infectious group with monomicrobial agents (335 cases), and an infectious group with unknown agents (599 cases) was performed. The results were as follows; (1) The highest percentage of patients were elderly and bedridden. (2) Striking atypical pneumonic symptoms, including dyspnea, consciousness disturbance, gastrointestinal symptoms and hypotension (shock) were present. (3) Laboratory findings of poor nutritional conditions, including decreases in serum protein, albumin, and cholineesterase, and hypoxia remarkably increased. (4) The prognosis was poor because the mortality rate (15.7%) was higher. (5) There were two polymicrobial agents for 75 patients and three agents for 8 patients. The coupling of polymicrobial agents was most frequent in five patients with Haemophilus influenzae + MSSA and five with H. influenzae + respiratory virus. These results suggest that the patients with community-acquired pneumonia caused by a mixed infection of polymicrobial agents had clinical features and causative microorganisms resembling those of elderly patients with community-acquired pneumonia. We recommended that treatment with antibiotics for them was adequate if the treatment resemble that of elderly patients.     

Incidence and clinical features of community-acquired legionellosis in hospitalized patients

In a two-year prospective study of patients hospitalized because of community-acquired pneumonia, the incidence of legionellosis was found to be 3.8% (17/442 cases). After S. pneumoniae, M. pneumoniae and influenzae viruses, legionellae were the fourth most frequently identified pneumonia agents. We evaluated the clinical data from 41 cases with legionellosis, 17 diagnosed in this prospective study and 24 prior to the study. The age range of all patients (22 women, 19 men) was 24-78 yrs (median 61.3 yrs), 14 of 41 cases (34.1%) had extrapulmonary organ involvement. Twelve patients (29.3%) died. The fatality rate was 4.5% (1/22 cases) in patients treated with erythromycin, and 57.9% (11/19 cases) in patients treated with other antibiotics. Antibiotics effective in legionellosis should be added to the routine therapy of community-acquired pneumonia when this aetiology can not be excluded.     

Clinical analysis of patients with community-acquired pneumonia requiring hospitalization classified by age group

We classified 1017 patients with community-acquired pneumonia requiring hospitalization experienced in Kawasaki Medical School Kawasaki Hospital during the past 15 years into five age groups (< or = 54 years old, 55-64 years old, 65-74 years old, 75-84 years old, > or = 85 years old). With particular emphasis on the elderly patients, we then compared the clinical and microbiological findings in the five groups. The results were as follows; (1) Half of patients in the over 85 years old group were bed-ridden. (2) The proportion receiving antibiotics before hospitalization decreased with age. (3) There were striking atypical pneumonic symptoms, such as dyspnea and consciousness disturbance in the two age groups over 75 years old. (4) Hypotension (shock) increased with age. (5) Markers of nutritional conditions, such as serum protein, albumin, cholinesterase, and hypoxia remarkably increased in the two age groups over 75 years old. (6) There were no significant differences in the isolation rate of etiological microorganisms. (7) The number of polymicrobial agents in the < or = 54 years old group was lower than that in the other age groups. (8) Mycoplasma pneumoniae was most significantly higher in < or = 54 years old group, Haemophilus influenzae in patients 55-64 years old, and Streptococcus pneumoniae in both 65-74 and 75-84 years old groups. (9) The isolation rate of MSSA, gram-negative bacilli such as Klebsiella pneumoniae, Pseudomonas aeruginosa, respiratory viruses increased with age. (10) The amount of sepsis increased with age. (11) The prognosis was poor in the two groups over 75 years old because the mortality rate (over 10%) was higher that for the other age groups.     

Epidemiology, clinical characteristics and antimicrobial resistance patterns of community-acquired pneumonia in 1702 hospitalized children in Singapore

OBJECTIVE AND BACKGROUND: Childhood community-acquired pneumonia (CAP) remains a leading cause of morbidity and mortality worldwide. The features of childhood CAP vary between countries. The aim of this study was to delineate the clinical characteristics, complications, spectrum of pathogens and patterns of antimicrobial resistance associated with hospitalized cases of childhood CAP in Singapore. METHODS: A retrospective study was conducted of patients discharged from Singapore's only children's hospital over a 3-year period with a principal diagnosis of CAP. RESULTS: A total of 1702 children, with a median age of 4.2 years (range: 1 month-16.3 years) were enrolled. A pathogen was identifiable in 38.4% of cases, including Mycoplasma pneumoniae in 20.3%, typical respiratory bacteria in 10.3% (64.6%Streptococcus pneumoniae; 21.7% non-typeable Haemophilus influenzae), viruses in 5.5% and mixed bacterial/viral infections in 2%. The majority of M. pneumoniae infections were in school-aged children (>5 years). Severity of infection was greater in CAP caused by typical bacteria, as reflected by length of hospital stay, CRP level, white cell and absolute neutrophil counts. Mortality from typical bacterial infections (8.9%) exceeded that from M. pneumoniae (0.3%) and viral pneumonias (0%) (P < 0.001). Aminopenicillins were often prescribed empirically for suspected S. pneumoniae and H. influenzae infections; however, resistance to these agents was frequently documented among S. pneumoniae (58.5%) and H. influenzae isolates (51%). CONCLUSION: In Singaporean children hospitalized with CAP, M. pneumoniae is the most commonly identified causative organism, followed by common respiratory viruses, S. pneumoniae and H. influenzae. Streptococcus pneumoniae and H. influenzae are associated with greater severity of infection than other organisms, and have high levels of resistance to commonly prescribed antibiotics.     

Clinical presentation of community-acquired Chlamydia pneumoniae pneumonia in adults

STUDY OBJECTIVE: To investigate the clinical presentation of community-acquired Chlamydia pneumoniae pneumonia in adults. DESIGN: Prospective study. SETTING: Kawasaki Medical School Hospital, Kawasaki Medical School Kawasaki Hospital, and Kurashiki Daiichi Hospital in Japan. PARTICIPANTS: Forty patients with community-acquired pneumonia with C pneumoniae as the only pathogen identified admitted to three hospitals between April 1996 and March 2001 and their clinical presentations were compared to patients with Streptococcus pneumoniae and Mycoplasma pneumoniae pneumonia. MEASUREMENTS: The diagnosis of C pneumoniae infection was based on isolation and serologic testing of antibodies by the microimmunofluorescence test. RESULTS: The clinical presentations, except for shortness of breath, were similar for the three major etiologic agents. The mean temperature of C pneumoniae patients on hospital admission was 37.9 degrees C, which was lower than that of patients with S pneumoniae and M pneumoniae. The mean WBC count on hospital admission was lower in the patients with C pneumoniae (mean, 9,100/microL) than in those with S pneumoniae pneumonia but higher than in those with M pneumoniae pneumonia. No patients required respiratory support or admission to an ICU, and no deaths occurred among the C pneumoniae pneumonia patients. CONCLUSIONS: Our results indicate that C pneumoniae pneumonia as a single etiologic agent is mild and that the underlying conditions and clinical symptoms closely resemble those of S pneumoniae pneumonia. However, the physical examinations, laboratory findings, and prognostic factors of the C pneumoniae patients resembled those of patients with M pneumoniae pneumonia.     

Mixed community-acquired pneumonia in hospitalised patients.

The role of mixed community-acquired pneumonia (CAP) is controversial. The aim of the present study was to determine the incidence, principal microbial patterns, clinical predictors and course of mixed CAP. The current study included 1,511 consecutive hospitalised patients with CAP. Of these, 610 (40%) patients had an established aetiology. One pathogen was demonstrated in 528 patients and 82 (13%) patients had mixed pneumonia. Cases including CAP, by a pyogenic bacteria and a complete paired serology for "atypicals", revealed that 82 (13%) patients had definite single pyogenic pneumonia and 28 patients (5%) had mixed pyogenic pneumonia. In patients with mixed CAP, Streptococcus pneumoniae was the most prevalent microorganism (44 out of 82; 54%). The most frequent combination was S. pneumoniae with Haemophilus influenzae (17 out of 82; 21%). Influenza virus A and S. pneumoniae (five out of 28; 18%) was the most frequent association in the mixed pyogenic pneumonia group. No clinical predictors for mixed pneumonias could be identified. Patients with mixed pyogenic pneumonia more frequently developed shock when compared with patients with single pyogenic pneumonia (18 versus 4%). In conclusion, mixed pneumonia occurs in >10% of cases with community-acquired pneumonia requiring hospitalisation.     

Differences in the etiology of community-acquired pneumonia according to site of care: a population-based study

BACKGROUND: A few population-based studies assessing the etiology of community-acquired pneumonia in both hospitalized and ambulatory patients, with special emphasis on the etiologic role of viral infections, have been reported. The purpose of this study was to assess microbiological differences according to initial site of care in patients with community-acquired pneumonia. METHODS: We studied 496 patients > 14 years of age collected from the study samples of three population-based studies carried out in the same geographical area ("Maresme" region in the Mediterranean coast in Barcelona, Spain) with the same methodology over an 8-year period (1987-1995). RESULTS: Fifty-six percent of patients were hospitalized and 44% were treated at home. Of the 474 patients with etiological evaluation, 195 patients had an identifiable etiology (overall diagnostic yield 41%). Streptococcus pneumoniae was the most common causative organism. Viral infection was diagnosed in 26.5% of hospitalized patients vs. 13.2% of ambulatory patients (P=0.03). Twenty-five percent of the 68 patients with documented etiology treated at home had Chlamydia pneumoniae infection compared with 14.3% of those treated in the hospital. Ten percent of hospitalized patients had pneumonia caused by two pathogens compared with 9.7% of ambulatory patients. The association of viruses and bacteria was the most frequent cause of dual infection (79% inpatients, 67% outpatients). CONCLUSIONS: This study has provided information on etiology of community-acquired pneumonia in hospitalized patients and in patients treated at home. A considerable proportion of patients had viral pneumonia, frequently requiring hospital admission for inpatient care.     

The comparison of patients with hospitalized health-care-associated pneumonia to community-acquired pneumonia

Health-care-associated pneumonia (HCAP) is defined as pneumonia that develops in patients with a history of recent hospitalization, hemodialysis as an outpatient, residence in a nursing home, outpatient intravenous therapy and home wound care. We aimed to compare the initial demographic characteristics, causative agents and prognosis between hospitalized HCAP and community-acquired pneumonia (CAP) patients. HCAP and CAP patients hospitalized between 01 September 2008-01 September 2009 were evaluated retrospectively. Out of 187 patients (131 males, mean age 66.3 ± 14.3 years) who were hospitalized during one-year period, 98 were diagnosed as HCAP and 89 as CAP. Among HCAP patients, 64 (65.3%) had a history of hospitalization in the last 90 days, 26 (26.5%) received outpatient intravenous therapy, 17 (17.3%) had home wound care, 6 (6.1%) were on hemodialysis program in the last 30 days and 4 (4.1%) lived in a nursing home. The causative pathogen was detected in 39 (39.8%) HCAP and 8 (9.0%) CAP patients. The most frequently isolated microorganisms were Pseudomonas aeruginosa and Acinetobacter baumannii in HCAP, and Streptococcus pneumoniae and Haemophilus influenzae in CAP patients. Inappropriate empiric antibiotic treatment was documented in 8 (25.8%) of 39 HCAP patients, in whom a causative agent was isolated whereas the antibiotic treatment was appropriate in all CAP patients. The duration of hospitalization (14.4 ± 11.4 vs. 10.7 ± 7.9 days, p= 0.011) and mortality rate (34.7% vs. 9.0%, p< 0.001) were higher in HCAP compared with CAP patients. As HCAP is different than CAP in terms of patients' characteristics, causative microorganisms and prognosis, it should be considered in all patients hospitalized as CAP. Potentially drug-resistant microorganisms should be taken into consideration in the empirical antibiotic treatment of these patients.     

Community-acquired pneumonia in patients requiring hospitalization

OBJECTIVE: This study aimed to investigate the microbial aetiology of community-acquired pneumonia (CAP) in patients requiring hospitalization. METHODOLOGY: A prospective study of consecutive non-immunocompromised patients aged 12 years and above admitted with CAP from August 1997 to May 1999 was undertaken. RESULTS: Of 127 patients hospitalized for CAP, an aetiological diagnosis was achieved in 53 cases (41.7%). Klebsiella pneumoniae was the most frequently isolated pathogen and caused 10.2% of all the cases, followed by Streptococcus pneumoniae (5.5%), Haemophilus influenzae (5.5%), Mycoplasma pneumoniae (3.9%) and Pseudomonas aeruginosa (3.9%). Gram-negative bacilli were significantly more frequently identified in patients aged 60 years or older and in patients with comorbid illnesses. Twelve of 13 patients who died from CAP had other comorbid illnesses compared to 63 of 114 patients who survived (P = 0.014). Three of eight bacteraemic patients died compared with 10 of 119 non-bacteraemic patients (P = 0.035). CONCLUSIONS: The microbiology of CAP in patients requiring hospitalization in Malaysia appears to be different from that in Western countries. Gram-negative bacilli were more frequently isolated in older patients and in those with comorbidity. Mortality from CAP is more likely in patients with comorbidity and in those who are bacteraemic.     

Community-acquired pneumonia in the elderly.

The incidence of community-acquired pneumonia (CAP) in the elderly is higher compared to younger populations. In addition, pneumonia in the elderly is a life-threatening problem. As our demographics have changed, clinicians have developed a heightened interest in managing pneumonia in the elderly. The development of pneumonia in elderly patients differs from that in younger individuals due to a complex array of factors. (1) The organisms involved depend on the setting in which the pneumonia developed: either the nonhospitalized elderly patient with CAP or the institutionalized patient who develops nursing-home-acquired pneumonia. (2) Underlying comorbid conditions commonly exist in the elderly that affect the etiology and outcome of pneumonia. Overall, Streptococcus pneumoniae and Haemophilus influenzae are still the most common etiologies of pneumonia in the elderly. The true role of gram-negative bacilli remains unclear although these micro-organisms may be more common etiologic agents in nursing-home pneumonia. Some recent studies from Mediterranean areas have reported high rates of infection by Chlamydia pneumoniae, but the real role of this micro-organism has to be confirmed. Another important issue is that the presenting symptoms of pneumonia in the elderly can be subtle and sometimes difficult to recognize. Fever is frequently absent, and delirium or alteration of functional physical capacity may be the only manifestations. Mortality in the elderly with CAP is higher when compared to younger populations. However, this may be explained by the concomitant presence of comorbid conditions more than by age per se. This statement has to be kept in mind when considering hospital and, particularly, intensive care unit admissions. Finally, antibiotic pharmacokinetics in the elderly populations with CAP ought to be considered to avoid frequent side-effects and complications. Overall, antibiotic regimens in hospitalized elderly patients with CAP do not differ from other hospitalized CAP populations. An organized approach to assessing elderly patients with suspicion of pneumonia and an awareness of common pitfalls in the management of this pulmonary infection in this population are essential to improving outcomes.     

Diagnosis of atypical pathogens in patients hospitalized with community-acquired respiratory infection

The object of our study was to determine the proportion of atypical respiratory pathogens among patients hospitalized with a community-acquired respiratory infection. From September 1997 to May 1999, 159 patients (57% male, median age 55, range 1-88 y) admitted to 3 regional hospitals for a community acquired respiratory infection, were enrolled in the study. Microbiological diagnosis for the atypical pathogens Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila was performed with PCR on a throat swab, sputum and/or broncho alveolar lavage (BAL). In addition, Legionella species other than L. pneumophila (L. non-pneumophila species) were detected by PCR. Two serum samples were collected and processed for M. pneumoniae and C. pneumoniae serology. In total, 27 patients (17%) were diagnosed with an atypical pathogen. Infection with M. pneumoniae was detected in 19 patients (12%) (PCR positive n = 7), with C. pneumoniae in 5 patients (3%) (PCR positive n = 0) and with L. pneumophila in 4 patients (2.5%) (PCR positive n = 4). In 54 (34%) patients routine microbiological investigations revealed aetiological agents other than the 3 atypical pathogens, the most frequently diagnosed pathogens being Streptococcus pneumoniae (n = 18), Haemophilus influenzae (n = 17), Gram-negative rods (n = 13), Moraxella catarrhalis (n = 6) and Staphylococcus aureus (n = 6). More than 1 pathogen was found in 13 patients. Atypical pathogens were found more often in the young age group (0-18 y), in contrast to bacterial pathogens that were found more often in the older age groups (> or = 65 y). Atypical pathogens were found less often in patients with a clinical presentation of atypical pneumonia. Legionella species other than L. pneumophila were found by PCR in 13 patients (8%), and in 6 patients in combination with another pathogen. An atypical pathogen (M. pneumoniae, C. pneumoniae or L. pneumophila) was found in 17% of the patients hospitalized with a community acquired respiratory infection, predominantly in the young age group. The role of Legionella non-pneumophila species as pathogen in community acquired respiratory infection needs to be determined. The clinical presentation does not predict the type of pathogen found.     

Etiology of community-acquired pneumonia in hospitalized patients in chile: the increasing prevalence of respiratory viruses among classic pathogens

BACKGROUND AND STUDY OBJECTIVES: The range and relative impact of microbial pathogens, particularly viral pathogens, as a cause of community-acquired pneumonia (CAP) in hospitalized adults has not received much attention. The aim of this study was to determine the microbial etiology of CAP in adults and to identify the risk factors for various specific pathogens. METHODS: We prospectively studied 176 patients (mean [+/- SD] age, 65.8 +/- 18.5 years) who had hospitalized for CAP to identify the microbial etiology. For each patient, sputum and blood cultures were obtained as well as serology testing for Mycoplasma pneumoniae and Chlamydophila pneumoniae, urinary antigen testing for Legionella pneumophila and Streptococcus pneumoniae, and a nasopharyngeal swab for seven respiratory viruses. RESULTS: Microbial etiology was determined in 98 patients (55%). S pneumoniae (49 of 98 patients; 50%) and respiratory viruses (32%) were the most frequently isolated pathogen groups. Pneumococcal pneumonia was associated with tobacco smoking of > 10 pack-years (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.2 to 5.4; p = 0.01). Respiratory viruses were isolated more often in fall or winter (28%; p = 0.011), and as an exclusive etiology tended to be isolated in patients >/= 65 years of age (20%; p = 0.07). Viral CAP was associated with antimicrobial therapy prior to hospital admission (OR, 4.5; 95% CI, 1.4 to 14.6). CONCLUSIONS: S pneumoniae remains the most frequent pathogen in adults with CAP and should be covered with empirical antimicrobial treatment. Viruses were the second most common etiologic agent and should be tested for, especially in fall or winter, both in young and elderly patients who are hospitalized with CAP.     

Etiology of community-acquired pneumonia treated in an ambulatory setting

BACKGROUND: Very few studies have addressed the etiology of community-acquired pneumonia (CAP) treated in an ambulatory setting. METHODS: Patients were recruited from physicians' offices and from Emergency Rooms in Canada. Pneumonia was defined as two or more respiratory symptoms and signs and a new opacity on chest radiograph interpreted by a radiologist as pneumonia. Blood and sputum for culture as well as acute and convalescent serum samples for serology were obtained. Antibodies to Mycoplasma pneumoniae and Chlamydia pneumoniae were determined using enzyme-linked immunosorbent assays. RESULTS: Five hundred and seven patients were enrolled in the study; 419 (82%) had blood cultures done, seven (1.4%) of which were positive for Streptococcus pneumoniae; 241 (47.5%) had a sputum processed for culture, 31% of which were positive for a potential respiratory pathogen. 437 (86.2%) had both acute and convalescent serum samples obtained, 148 (33.8%) of which gave a positive result. Overall an etiological diagnosis was made in 48.4% of the patients. M. pneumoniae accounted for 15% of the cases, C. pneumoniae 12%, S. pneumoniae 5.9% and Haemophilus influenzae 4.9%. CONCLUSIONS: Despite considerable effort an etiological diagnosis of CAP treated on an ambulatory basis was made in only half the patients. The most commonly identified pathogens were M. pneumoniae, C. pneumoniae, S. pneumoniae,     

Pathogenetic study on bronchopulmonary infections in 1,416 patients by transtracheal aspiration method]

We have performed transtracheal aspiration (TTA) in 1,416 patients, who were suspected to have bronchopulmonary infection, in order to collect non-contaminated specimens directly from the lower airway. The overall isolation rates in 1,416 TTA were 68.7% for any microorganisms. Aerobes had a high incidence but many kinds of microorganisms were associated with bronchopulmonary infections. Haemophilus influenzae was the major pathogen in patients with acute bronchitis. Streptococcus pneumoniae was the most important pathogen and mycoplasma was often isolated in patients with community-acquired pneumonia. Major pathogens of nosocomial pneumonia consisted of alpha-streptococcus spp., anaerobes and Pseudomonas aeruginosa. Anaerobes were isolated from transtracheal aspirates in 20 of 33 episodes of lung abscesses. H. influenzae and P. aeruginosa were the main persistent pathogens and H. influenzae, S. pneumoniae and anaerobes were important exacerbated pathogens in patients with chronic lower respiratory tract infection. S. pneumoniae was isolated more from TTA than expectorated sputa. Oropharyngeal flora bacteria were easily isolated in the culture of expectorated sputa. We assessed the final diagnosis or causative factor in 443 patients whom no microorganism was isolated from transtracheal aspirates. The final diagnosis was infectious diseases in 52 patients (11.7%) and non-infectious diseases in 80 patients (18.1%), respectively. The causative factor was unsuited TTA sample in 81 patients (18.3%), preceding antimicrobial chemotherapy in 95 patients (21.4%) and unknown in 135 patients (30.5%), respectively. The pathogenesis of bronchopulmonary infections is complex and various microorganisms are associated with pathogens of bronchopulmonary infections. Therefore, we should accurately diagnose the pathogens in patients with bronchopulmonary infections. TTA is one of the useful methods that we can accurately detect the respiratory pathogens.     

Etiologies and treatment outcomes for out-patients with community-acquired pneumonia (CAP) at Srinagarind Hospital, Khon Kaen, Thailand

Most patients with community-acquired pneumonia are treated as out-patients with empirical therapy, since initially the etiologic agent is unknown. We prospectively assessed the etiologies and treatment outcomes of pneumonia from February 2003 to 2004 at ambulatory clinics. Forty-four patients were included with a mean age of 49.2 (SD 18.2) years. The male to female ratio was 1:1.4. The incubation period was 6.9 (SD 4.4) days. Half of the patients were healthy. Asthma and COPD were common in patients with underlying diseases. The etiologic diagnosis was determined by a sputum culture and a serology test of paired serum samples. Hemo-culture produced no growth in any patients. Atypical pathogens and H. influenzae were the most common finding, each occurring in 31.8% of the patients followed by S. pneumoniae and H. parainfluenzae (27.3% each). Twenty-two patients were infected with multiple pathogens. C. pneumoniae was the most common co-infecting pathogen. Two of 12 S. pneumoniae isolates were penicillin resistant. Nine of 14 H. influenzae isolates were cotrimoxazole resistant and 8 of 14 were not sensitive to erythromycin. For H. parainfluenzae, 11 of 12 isolates were not sensitive to erythromycin, and 7 of 12 were not sensitive to cotrimoxazole. Oral antibiotics were prescribed as out-patient treatment. Forty patients (90.9%) improved, with symptoms-score improvement averaging 6.4 days. Four patients got worse and needed a change of antibiotics, the symptoms usually worsen within 3-5 days. We conclude that, antibiotics for CAP out-patients should cover atypical pathogens, H. influenzae, S. pneumoniae and H. parainfluenzae. If the clinical symptoms do not respond after 3-5 days of out-patient treatment, resistance or an unusual organism (eg B. pseudomallei) should be considered.     

Pneumonia in the elderly (geriatric) population

PURPOSE OF REVIEW: Review of recent studies (2003 and 2004) concerning pneumonia in the very old. RECENT FINDINGS: Hospitalisation for community-acquired pneumonia (CAP) in the elderly is associated with a high mortality and with a high rate of readmission within the following year. Functional status, altered mental status, number of comorbidities, aspiration pneumonia, renal failure, and nutritional status are all indicators of adverse prognosis. Although Streptococcus pneumoniae, Haemophilus influenzae, Enterobacteriacae, and Staphylococcus aureus are the most frequently identified causative microorganisms, viruses account for up to 26% of hospital admissions for CAP. Chlamydia pneumoniae is also implicated in CAP and in nursing-home-acquired pneumonia (NHAP), with recent reports of outbreaks in nursing homes. Aspiration pneumonia is frequent in the elderly and occurs with increased frequency in patients with nasogastric tubes or percutaneous enterogastric tubes. In severe aspiration pneumonia, 20% of organisms implicated are anaerobic and 80% aerobic, most of which are gram-negative Enterobacteriaceae. Poor oral hygiene increases subsequent risk of pneumonia: dental plaque may act as a reservoir for pathogenic organisms implicated in CAP or NHAP. Prevention of CAP and NHAP relies on the combined use of influenza and pneumococcal vaccination, which decreases hospital admissions and in-hospital mortality for CAP. SUMMARY: Recent studies stress the importance of aspiration as a frequent mechanism of CAP, provide new insights as to causative organisms in this setting, and underline the contribution of combined vaccination in reducing morbidity and mortality.