Community-acquired pneumonia requiring hospitalization: 5-year prospective study

We studied all patients with community-acquired pneumonia who were admitted to our 800-bed adult acute care hospital from 1 November 1981 to 15 March 1987. The 719 patients had a mean age of 63.2 years; 18% were admitted from nursing homes, and 18% required ventilatory assistance as part of the therapy for pneumonia. Patients with nursing home-acquired pneumonia were significantly older; had a higher mortality (40% vs. 17%); were more likely to be admitted in January; were less likely to complain of cough, fever, anorexia, chills, headache, nausea, sore throat, myalgia, or arthralgia; and were more likely to be confused than those admitted from the community. Pneumonia of unknown etiology and aspiration pneumonia were more common and Mycoplasma pneumoniae infection less common among those with nursing home-acquired pneumonia. Streptococcus pneumoniae accounted for 58% of the 48 cases of bacteremia. None of the bacteremic patients received antibiotics before admission, compared with 34% of the nonbacteremic patients. Aerobic gram-negative rod bacteremia was not more frequent among nursing home patients than among those from the community. The overall mortality was 21% (8.5% for those less than 60 years of age and 28.6% for those greater than 60 years old). By multivariate analysis the following variables were significant predictors of mortality: number of lobes involved by the pneumonic process, number of antibiotics used to treat the pneumonia, age, admission from a nursing home, ventilatory support, and the number of complications that occurred while the patient was in the hospital.     

Community-acquired Chlamydia pneumoniae pneumonia in Japan: a prospective multicenter community-acquired pneumonia study

OBJECTIVE: To investigate the clinical features of Chlamydia pneumoniae pneumonia in Japan and to evaluate the newly created Japanese community-acquired pneumonia (CAP) guidelines. PATIENTS AND METHODS: A multicenter CAP surveillance study was carried out in 20 hospitals between December 1999 and March 2000. The diagnosis of C. pneumoniae infection was based on isolation in cell culture, the polymerase chain reaction and serologic testing of antibodies by the microimmunofluorescence test. RESULTS: Among 232 CAP cases, C. pneumoniae was identified as the etiologic agent in 15 cases (6.5%). C. pneumoniae was the only pathogen identified in nine of these cases, while one or more additional etiological agents were found in the other six cases. Of the present and previously reported single agent C. pneumoniae pneumonia cases, about 50% were more than 60 years old and had underlying diseases. A relatively slow pulse rate in relation to fever was not seen in these patients. The mean WBC count of all patients was normal. No patient required respiratory support or admission to an intensive care unit and no deaths occurred among these patients. CONCLUSION: The clinical pictures of C. pneumoniae pneumonia as a single agent were mild to moderate and were remarkably different from those of cases of C. pneumoniae pneumonia concomitant with other bacteria. If the patient is less than 60 years old and some guideline headings are excluded, we think it would be possible to distinguish between C. pneumoniae and bacterial pneumonia.     

Community-acquired acinetobacter pneumonia.

Acinetobacter calcoaceticus var anitratus, a nonfermentative grampnegative bacillus, has been infrequently reported as a cause of community-acquired pneumonia. In this paper we describe the course of six recent patients with community-acquired, bacteremic pneumonia due to this organism and review the six previously reported cases. Our experience suggests this organism is a more common cause of community-acquired pneumonia than previously thought. Acinetobacter pneumonia occurs in older persons with chronic disease, especially alcoholism. It is a fulminant illness with respiratory distress, hypoxemia, leukopenia and shock. Chest roentgenograms reveal a lobar or bronchopneumonic infiltrate which often becomes bilateral within 24 hours of admission to the hospital. Pleural effusions are common. The mortality rate is 43 per cent. Factors that predict a fatal outcome are granulocytopenia, empyema and therapy with inappropriate antibiotics. Therapy with appropriate antibiotics, especially carbenicillin and an aminoglycoside, increases survival.     

Community-acquired pneumonia

This seminar reviews important features and management issues of community-acquired pneumonia (CAP) that are especially relevant to immunocompetent adults in light of new information about cause, clinical course, diagnostic testing, treatment, and prevention. Streptococcus pneumoniae remains the most important pathogen; however, emerging resistance of this organism to antimicrobial agents has affected empirical treatment of CAP. Atypical pathogens have been quite commonly identified in several prospective studies. The clinical significance of these pathogens (with the exception of Legionella spp) is not clear, partly because of the lack of rapid, standardised tests. Diagnostic evaluation of CAP is important for appropriate assessment of severity of illness and for establishment of the causative agent in the disease. Until better rapid diagnostic methods are developed, most patients will be treated empirically. Antimicrobials continue to be the mainstay of treatment, and decisions about specific agents are guided by several considerations that include spectrum of activity, and pharmacokinetic and pharmacodynamic principles. Several factors have been shown to be associated with a beneficial clinical outcome in patients with CAP. These factors include administration of antimicrobials in a timely manner, choice of antibiotic therapy, and the use of a critical pneumonia pathway. The appropriate use of vaccines against pneumococcal disease and influenza should be encouraged. Several guidelines for management of CAP have recently been published, the recommendations of which are reviewed.     

Community-acquired pneumonia

Community-acquired pneumonia (CAP) remains a leading cause of morbidity and mortality worldwide and has significant financial implications for health-care systems. The epidemiology and fundamental biology of the disease has evolved, reflecting the human immunodeficiency virus pandemic, increasing world travel, and, as always, poverty. The promise held out by molecular diagnostic technology has yet to deliver in this arena, and antibiotic resistance continues to drive the quest for new antimicrobial agents. The emergence of multidrug-resistant Streptococcus pneumoniae, the microorganism most often implicated as a cause of CAP, continues to threaten treatment options. The evolution of this organism, the persistently high mortality rate associated with CAP, and increasing health-care costs have prompted the publication of guidelines by various authorities that can be used to assist in the initial assessment of the patient and then guide empirical antimicrobial therapy. It is unclear whether these guidelines will have significant impact on cost and mortality, although the trend toward a rational and evidence-based approach to antimicrobial therapy must be a goal to aspire to.     

Community-acquired pneumonia

Community-acquired pneumonia (CAP) is the most common form of severe infectious disease in developed countries. The mortality is particularly high in elderly patients. For risk stratification simple clinical scores such as the CRB-65 (confusion, respiratory rate, blood pressure, age over 65 years) are recommended. The spectrum of pathogens is characterized by Pneumococcus and Haemophilus influenzae as well as atypical and viral pathogens. Resistance plays a subordinate role in Germany. In addition to the clinical symptoms an X-ray examination is also helpful to confirm the diagnosis and biomarkers can also be useful. Microbiological investigations are not necessary in practice. Particularly in cases of uncharacteristic clinical symptoms and therapy failure there are many differential diagnoses which can be hidden behind the clinical diagnosis of pneumonia. The calculated treatment of CAP should correspond to the current recommendations in national guidelines. The options for prevention by general measures and vaccinations should be applied consistently.     

Community-acquired pneumonia

Community-acquired pneumonia (CAP) remains an important cause of morbidity and mortality. Streptococcus pneumoniae is the most common pathogen and respiratory syncitial virus the most important viral pathogen in children. The role of urinary antigen testing and PCR for the diagnosis forS. pneumoniae infection has been an important adjunct to clinical examination, showing good sensitivity and specificity. Host-related immune responses play an important role in defining the severity of illness. Other than the use of Activated Protein C and immunization, the clinical use of therapies designed to modulate these abnormal responses remains largely experimental. The 7-valent vaccine represents a major advance in the prevention of invasive pneumococcal disease. The importance of effective triage and the deleterious effects of deviation from protocols are underscored. Continuous positive pressure ventilation and noninvasive mechanical ventilation are available as options for respiratory support in cases of severe CAP and require further evaluation.     

Community-acquired pneumonia in the elderly: Spanish multicentre study.

Community-acquired pneumonia (CAP) in the elderly has increased as a consequence of an overall increase of the elderly population. A controversy about the aetiology and outcome of CAP in this population still exists and more epidemiological studies are needed. A prospective, 12-month, multicentre study was carried out to assess the clinical characteristics, aetiology, evolution and prognostic factors of elderly patients (> or = 65 yrs) admitted to hospital for CAP. The study included 503 patients (age 76 +/- 7 yrs). The clinical picture lasted < or = 5 days in 318 (63%) and the main clinical features were cough (n = 407, 81%) and fever (n = 380, 76%). Aetiological diagnosis was achieved in 199 (40%) cases, with a definite diagnosis obtained in 164 (33%). Of the 223 microorganisms isolated the main agents found were Streptococcus pneumoniae in 98 (49%) and Haemophilus influenzae in 27 (14%). A total of 53 patients died (11%) and the multivariate analysis showed the following factors of bad prognosis: previous bed confinement, alteration in mental status, absence of chills, plasma creatinine > or = 1.4 mg x dL(-1), oxygen tension in arterial blood/inspiratorv oxygen fraction ratio < 200 at the time of admission, and shock and renal failure during the evolution. The results of this study may aid in the management of empiric antibiotic treatment in elderly patients with community-acquired pneumonia and the patients who have a greater probability of bad evolution may be identified based on the risk factors.     

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.     

Community-acquired viral pneumonia

Advanced age often is associated with functional and immunologic decline and chronic cardiopulmonary diseases that predispose to pneumonia when viral infection occurs. Influenza virus remains the primary viral pathogen in the elderly, although the impact of the other respiratory viruses remains to be defined. The clinical syndromes associated with respiratory viruses frequently are indistinguishable from one another or bacterial pathogens; often, viral illness in older adults exacerbates underlying conditions, complicating diagnosis. Antiviral therapy is available for influenza A and B; specific viral diagnosis, particularly with the use of rapid antigen detection, may be useful for clinical management. Treatment for other viruses primarily is supportive.     

Community-acquired pneumonia in the elderly.

Pneumonia in the elderly is a common and serious problem with a clinical presentation that can differ from that in younger patients. Older patients with pneumonia complain of significantly fewer symptoms than do younger patients, and delirium commonly occurs. Indeed, delirium may be the only manifestation of pneumonia in this group of patients. Alcoholism, asthma, immunosuppression, and age >70 years are risk factors for community-acquired pneumonia in the elderly. Among nursing home residents, the following are risk factors for pneumonia: advanced age, male sex, difficulty in swallowing, inability to take oral medications, profound disability, bedridden state, and urinary incontinence. Streptococcus pneumoniae is the most common cause of pneumonia among the elderly. Aspiration pneumonia is underdiagnosed in this group of patients, and tuberculosis always should be considered. In this population an etiologic diagnosis is rarely available when antimicrobial therapy must be instituted. Use of the guidelines for treatment of pneumonia issued by the Infectious Diseases Society of America, with modification for treatment in the nursing home setting, is recommended.     

Bacteremic and nonbacteremic pneumococcal pneumonia. A prospective study

We prospectively identified cases of pneumococcal pneumonia and used stringent criteria to stratify them into bacteremic and nonbacteremic cases. Although patients were distributed among racial groups in proportion to all patients seen at this medical center, the proportion of African-Americans with bacteremic disease was significantly increased. All patients had at least 1 underlying condition predisposing to pneumococcal infection, and most had several. Although the mean number of predisposing factors was greater among bacteremic patients than nonbacteremic patients, only alcohol ingestion was significantly more common. Nearly one-third of patients had substantial anemia (hemoglobin < or = 10 g/dL) on admission, which may have predisposed to infection. In the case of other laboratory abnormalities, such as albumin, creatinine, and bilirubin, it was difficult to determine which abnormality might have predisposed to pneumococcal infection and which might have resulted from it. The radiologic appearance was varied. Airspace consolidation and air bronchogram on chest X-ray were highly associated with bacteremic disease, as was the presence of pleural effusion. Although the Pneumonia Patient Outcomes Research Team (PORT) risk score was a predictor of mortality, it did not help to predict the presence of bacteremia in an individual case. Most patients who died in the first week in hospital were bacteremic, and a high PORT risk score with bacteremia reliably predicted a high likelihood of a fatal outcome. Eleven patients had extrapulmonary disease with meningitis, empyema, and septic arthritis predominating; all of these patients were bacteremic. The antibiotic susceptibility of our strains correlated well with those that have been reported in the United States during the years of this study. The use of numerous antibiotics of different classes in many patients, especially those who were the most ill, precluded analysis of outcome based on antibiotic therapy. Only 17 patients had been vaccinated. Since nearly all patients had conditions for which pneumococcal vaccine is recommended and more than one-third had been hospitalized in the preceding 6 months, the low rate of vaccination can be regarded as a missed opportunity to administer a potentially beneficial vaccine.     

A prospective study of community-acquired pneumonia in Hong Kong.

A prospective study of community-acquired pneumonia in Hong Kong was carried out between January and December, 1988. Ninety adults (57 male) with a mean age of 57.3 years were admitted to the Prince of Wales Hospital with community-acquired pneumonia. The etiologic diagnosis of pneumonia was made in 37 cases (41 percent). Pneumococcal infection was diagnosed in 11 patients (12 percent). The same number of patients had pulmonary tuberculosis presenting as acute pneumonia. It could not be differentiated from other causes of pneumonia on clinical and radiologic grounds, although pleural effusion and upper lobe involvement were more common in patients with tuberculosis. Chlamydia species were identified in five patients (6 percent) and Mycoplasma pneumoniae was identified in three patients (3 percent). There was no case of Legionnaires' disease. The etiologic agent could not be identified in 59 percent of cases. The low incidence of etiologic diagnosis of community-acquired pneumonia was probably related to the widespread use of antibiotics in private practice. Tuberculosis is an important cause of community-acquired pneumonia in Hong Kong and this diagnosis should be considered in patients who fail to respond to first-line antibiotics.     

Community-acquired pneumonia in children

PURPOSE OF REVIEW: This review highlights recent developments in the diagnosis, etiology, therapy, and prevention of community-acquired pneumonia in children. RECENT FINDINGS: Sensitive new diagnostic methods have increased the detection rate of the causative agent up to 94%. Streptococcus pneumoniae is the most prevalent bacterial pathogen in all ages. Polymerase chain reaction is a rapid and sensitive method for the detection of Chlamydia pneumoniae and Mycoplasma pneumoniae, which have gained greater importance in recent years. During the period covered by this review, two new agents causing pneumonia were extensively studied. Human metapneumonovirus detected in young children is a leading cause of respiratory disease during the first years of life. A novel coronavirus was identified as the causative agent of severe respiratory syndrome, a new respiratory illness that affects adults and children. One multicenter trial concluded that nonsevere pneumonia can be treated with a short course of oral amoxicillin and a multicenter international study showed that children with severe pneumonia have similar outcomes whether treated with oral amoxicillin or parenteral penicillin, but more data are needed to demonstrate the safety and efficacy of such regimens. SUMMARY: The continued evolution of bacterial resistance highlights the need for appropriate use of antibacterials. Improved diagnostic techniques will aid the treatment of children with community-acquired pneumonia. Aggressive vaccination with the pneumococcal conjugate vaccine and other available vaccines as well as the development of new vaccines will aid the prevention of respiratory disease in children.     

Community-acquired pneumonia in adults

Efforts to reduce hospitalization or the length of stay are common topics in papers published last year. Chlamydia pneumoniae is now recognized worldwide as a common pathogen in community-acquired pneumonia. A great variation in the frequency of various pathogens is found in different countries, stressing the importance of ascertaining the aetiological and epidemiological situation in each respective country.