Community-acquired pneumonia

Community-acquired pneumonia (CAP) is a significant cause of morbidity and mortality in all age groups, especially the elderly, which is a patient population that continues to grow. Recently the spectrum and clinical picture of pneumonia has been changing as a reflection of this aging population; this requires a reassessment of and a new approach to the patient with pneumonia. Currently, pneumonia patients are classified as having either community-acquired or hospital-acquired infection rather than typical versus atypical. Patients who have CAP are categorized by age, presence of a coexisting medical illness, and the severity of the pneumonia. The rationale behind categorizing patients is to stratify them in terms of mortality risk to help determine the location of therapy (e.g., outpatient, inpatient, intensive care unit) and focus the choice of initial antimicrobial therapy. Once the decision to hospitalize a patient with pneumonia is made, the next step is to decide on an appropriate diagnostic evaluation and antibiotic therapy. Both decisions have evolved over the last several years since the publication of the American Thoracic Society's CAP guidelines. The current approach to the diagnostic work-up of pneumonia stresses a limited role of diagnostic tests and procedures. The antimicrobial regimen has now evolved into one that is empiric in nature and based on the age of the patient, the presence of coexisting medical disease, and the overall severity of the pneumonia. This process is a dynamic once because bacterial resistance to commonly used antibiotics can further complicate the course of pneumonia therapy, but the impact of resistance on outcome is less clear. Resistance of Streptococcus pneumoniae to penicillin is a prime example of this growing problem, and adjustment to pneumonia therapy may be required. A difficult but not uncommon problem in pneumonia patients is slow recovery and delayed resolution of radiographic infiltrates. Factors that impact negatively on pneumonia resolution include advanced age and the presence of serious comorbid illnesses such as diabetes mellitus, renal disease, or chronic obstructive pulmonary disease. In addition, certain organism factors (e.g., intrinsic virulence) may interact with host factors and advanced age to delay pneumonia resolution. For example, 50% of patients with pneumococcal pneumonia have radiographic clearing at 5 weeks, and the majority clear within 2 to 3 months. Recent data demonstrate that radiographic resolution of CAP is most influenced by the number of lobes involved and the age of the patient. Radiographic clearance of CAP decreases by 20% per decade after age 20, and patients with multilobar infiltrates take longer to clear than those with unilobar disease. In general, when approaching slowly resolving infiltrates after pneumonia, bronchoscopic evaluation and lung biopsy are more likely to yield a specific diagnosis if the patient is a nonsmoker younger than 55 years old with multilobar disease. If the patients has either no identifiable factors associated with prolonged pneumonia resolution or the repeat chest radiograph at 1 month shows no appreciable change, further diagnostic testing is indicated. The route and duration of antibiotic therapy, another detail of the management of CAP patients that has changed recently, is complicated by the fact that the majority of patients with CAP have no pathogen identified. Therefore, in most instances the physician initiates empiric antibiotics on the basis of epidemiologic data. If an etiologic pathogen is identified (either initially or at a later time), then the antibiotic spectrum can be narrowed. When no pathogen is discovered, broad-spectrum empiric antibiotics are continued. (ABSTRACT TRUNCATED)     

Community-acquired pneumonia

Within the scope of producing cartilage tissue in a three-dimensional culture design, the stability of the used delivery substance in-vitro tissue product has to be improved. For this, carrier materials consisting of bioresorbable polymers, e. g. poly(L[+]-lactic acid) and poly(glycolic acid) can be used. In respect of the biocompatibility of these polymers, the effect of degradation products on chondrocytes is of major interest. The available biomaterials were tested on chondrocytes in form of their monomers, glycolic acid and L(+)-lactic acid. Effects in regard of cell activity were determined with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide( MTT)test. A non-pH-effect was examined by buffering with concentrated NaOH. In a short-term testing with increasing monomer concentrations as well as in a test over a twelve-day period, L(+)-lactic acid proved to have a lower cytotoxic effect on chondrocytes than glycolic acid. Similar results were obtained with buffered culture media. Therefore, poly(L[+]-lactic acid) can be recommended for the development of chondrocytes-polymer constructs for in-vitro engineering of cartilage tissue.     

Community-acquired pneumonia: Etiological diagnosis

Microbiological and immunoserological approaches were used in etiological diagnosis of community-acquired pneumonia. It was concluded that Streptococcus pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Legionella pneumophila and Klebsiella pneumoniae predominated in the etiological structure of present severe community-acquired pneumonia. The most actual causative agents of nonsevere community-acquired pneumonia in persons under 60 were S. pneumoniae, Hemophilus influenzae, Mycoplasma pneumoniae and Chlamydia pneumoniae. Nonsevere community-acquired pneumonia in persons over 60 and/ or at the background of chronic obstructive pulmonary diseases, diabetes mellitus or other affections was most frequently due to S. pneumoniae, H. influenzae and aerobic gramnegative microbes.     

Community-acquired pneumonia in adults: initial antibiotic therapy

One of the current goals in vaccine development is the noninvasive administration of protective antigens via mucosal surfaces. In this context, the gut-associated lymphoid tissues have already been extensively explored. Vaccination via the nasal route has only recently been the focus of intensive investigation, and no live vector specifically designed for the respiratory mucosa is yet available. In this study we show that intranasal administration of the recombinant Bordetella pertussis BPGR60, producing the Schistosoma mansoni 28-kDa glutathione S-transferase (Sm28GST) protective antigen fused to filamentous hemagglutinin, induces priming in mice for the production of serum antibodies. In addition to significant levels of anti-Sm28GST immunoglobulin A (IgA) antibodies, high levels of anti-Sm28GST serum antibodies were obtained after intranasal boost with the purified antigen or infection with S. mansoni following intranasal priming with BPGR60. These antibodies were of the IgG1, IgG2a, and IgG2b isotypes, suggesting a mixed immune response. No priming was observed in animals that had received nonrecombinant B. pertussis or purified Sm28GST, indicating specific priming by BPGR60. This priming was also evident in immune protection against S. mansoni challenge. Significant protection against worm burden and egg output was obtained in mice primed with BPGR60 and intranasally boosted with purified Sm28GST. A lower but still significant degree of protection against egg output was also obtained in mice infected with a single dose of BPGR60. These results indicate that intranasal administration of recombinant B. pertussis can prime for serum antibody responses against a foreign antigen and for heterologous protection.     

Community-acquired pneumonia in the elderly. Clinical and nutritional aspects

Community-acquired pneumonia (CAP) in the elderly has a different clinical presentation than CAP in other age groups. Confusion, alteration of functional physical capacity, and decompensation of underlying illnesses may appear as unique manifestations. Malnutrition is also an associated feature of CAP in this population. We undertook a study to assess the clinical and nutritional aspects of CAP requiring hospitalization in elderly patients (over 65 yr of age). One hundred and one patients with pneumonia, consecutively admitted to a 1,000-bed teaching hospital over an 8-mo period, were studied (age: 78 +/- 8 yr, mean +/- SD). Nutritional aspects and the mental status of patients with pneumonia were compared with those of a control population (n = 101) matched for gender, age, and date of hospitalization. The main symptoms were dyspnea (n = 71), cough (n = 67), and fever (n = 64). The association of these symptoms with CAP was observed in only 32 patients. The most common associated conditions were cardiac disease (n = 38) and chronic obstructive pulmonary disease (COPD) (n = 30). Seventy-seven (76%) episodes of pneumonia were clinically classified as typical and 24 as atypical. There was no association between the type of isolated microorganism and the clinical presentation of CAP, except for pleuritic chest pain, which was more common in pneumonia episodes caused by classical microorganisms (p = 0.02). This was confirmed by a multivariate analysis (relative risk [RR] = 11; 95% confidence interval [CI]: 1.7 to 65; p = 0.0099). The prevalence of chronic dementia was similar in the pneumonia cohort (n = 25) and control group (n = 18) (p = 0.22). However, delirium or acute confusion were significantly more frequent in the pneumonia cohort than in controls (45 versus 29 episodes; p = 0.019). Only 16 patients with pneumonia were considered to be well nourished, as compared with 47 control patients (p = 0.001). Kwashiorkor-like malnutrition was the predominant type of malnutrition (n = 65; 70%) in the pneumonia patients as compared with the control patients (n = 31; 31%) (p = 0.001). The observed mortality was 26% (n = 26). Pleuritic chest pain is the only clinical symptom that can guide an empiric therapeutic strategy in CAP (typical versus atypical pneumonia). Both delirium and malnutrition were very common clinical manifestations of CAP in our study population.     

Community-acquired pneumonia: prospective study of 101 adult, immunocompetent patients for 1 year

BACKGROUND: A one year prospective study was carried out to assess the etiology of community-acquired pneumonia (CAP), and also to know the incidence, characteristics and evolution of infection by Chlamydia pneumoniae; and the effectiveness of DNA probes in CAP due to Mycoplasma pneumoniae and Legionella. METHODS: One hundred and ten patients with a diagnosis of CAP in the emergency department were studied. Serologic studies were performed, and also tests commonly used for the diagnosis of respiratory tract pathogens in respiratory samples, including serology and culture of Chlamydia pneumoniae and DNA probes for Mycoplasma pneumoniae and Legionella. RESULTS: In 72 cases (71.3%) some pathogen was found and in 5 cases more than one microorganism was involved. The etiology was bacterial in 31% of the cases, with S. pneumoniae being the most frequent (19 cases). Forty percent of the cases were "atypical" pneumonias with 33 cases of M. pneumoniae and 5 by Chlamydia pneumoniae. Diagnostic data of viral pneumonia were found in 2 cases. DNA probes were not useful for the diagnosis of pneumonia by Legionella pneumophila and had low effectiveness (31.8%) in Mycoplasma pneumoniae CAP. CONCLUSIONS: a) M. pneumoniae was the most frequent pathogen (33%). b) DNA probes for M. pneumoniae had low sensitivity in sputum (31.8%) and none in pharyngeal exudate. c) Acute infection by C. pneumoniae was diagnosed in 5 cases. Previous data of infection were recorded in 60.4% of the patients. d) Bacterial pneumonia (31%) was underestimated due to a low rate of bacteremic cases (7.9%) and the low number of positive cultures with definitive diagnostic value. e) The evolution was good except in two cases (death due to staphylococcal pneumonia with alcohol withdrawal syndrome and multiorganic failure by disseminated chicken-pox).     

Community-acquired pneumonia in adults: guidelines for management. The Infectious Diseases Society of America

This is part of the series of practice guidelines commissioned by the Infectious Diseases Society of America through its Practice Guidelines Committee. The purpose of this guideline is to provide assistance to clinicians in the diagnosis and treatment of community-acquired pneumonia. The targeted providers are internists and family practitioners. The targeted groups are immunocompetent adult patients. Criteria are specified for determining whether the inpatient or outpatient setting is appropriate for treatment. Differences from other guidelines written on this topic include use of laboratory criteria for diagnosis and approach to antimicrobial therapy. Panel members and consultants are experts in adult infectious diseases. The guidelines are evidence based where possible. A standard ranking system is used for the strength of the recommendations and the quality of the evidence cited in the literature reviewed. The document has been subjected to external review by peer reviewers as well as by the Practice Guidelines Committee and was approved by the IDSA Council. An executive summary and tables highlight the major recommendations. The guidelines will be listed on the IDSA home page at http://www.idsociety.org.     

Community-acquired bacteremia in HIV-positive patients: protective benefit of co-trimoxazole

OBJECTIVE: To evaluate the effect of the type of Pneumocystis carinii pneumonia (PCP) prophylaxis on the development of community-acquired bacteremia. DESIGN: Case-control study using all cases of community-acquired bacteremia identified prospectively during a longitudinal study of all infections in a cohort of HIV-infected persons. SETTING: University-affiliated Department of Veterans Affairs Medical Center HIV program. PATIENTS: All patients with community-acquired bacteremia seen at the facility between January 1990 and December 1995 were included. Controls, seen at the same facility and matched by date and CD4 count, were used to assess risk factors. A total of 57 cases and 114 controls were analysed. MAIN OUTCOME MEASURES: Risk of development of bacteremia, distribution of organisms, and effect of specific prophylactic regimens for PCP. RESULTS: Bacteremia was caused by Staphylococcus aureus (23%), Pseudomonas aeruginosa (18%), Escherichia coli (16%), Streptococcus pneumoniae (14%) and others (31%). Groups were similar by age, race, HIV risk factors and CD4 count. The presence of an intravenous catheter was mildly predictive of the development of bacteremia [odds ratio (OR), 2.67; P = 0.024]. Type of PCP prophylaxis in cases and controls with CD4 < 200 x 10(6)/l included co-trimoxazole (trimethoprim-sulfamethoxazole, TMP-SMX; 31 and 60%, respectively), dapsone (33 and 24%, respectively) and aerosolized pentamidine (27 and 13%, respectively). Use of TMP-SMX (but not dapsone or aerosolized pentamidine) was associated with the absence of bacteremia (OR, 0.28; P = 0.001). A similar protective effect was found when controlling for the presence of an intravenous catheter. CONCLUSION: PCP prophylaxis with TMP-SMX apparently protects against community-acquired bacteremia in HIV-infected persons.     

Community-acquired Legionnaires'' disease following minimal exposure to a contaminated source

Gastric antral forceps biopsies taken at gastroscopy were cultured for Helicobacter pylori and tested for anti-microbial sensitivity. Using micro-aerophilic culture, and disc testing or E-testing, there was 98-100% sensitivity to amoxycillin, tetracycline, clarithromycin and erythromycin. However, there was apparent resistance to metronidazole in 19 of 102 samples (19%). When sensitivity by E-testing was performed with preliminary anaerobic culture for 24 h only two of 94 samples (2%) showed resistance. In 37 cultures both micro-aerophilic disc testing and anaerobic then micro-aerophilic E-testing were conducted. Eight cultures showed resistance upon disc testing (MIC > 5 mg/l) but all of these organisms were sensitive on E-testing (MIC 0.003-0.5 mg/l). Metronidazole may be used with confidence in eradication regimes.     

Community-acquired methicillin-resistant Staphylococcus aureus in children with no identified predisposing risk

OBJECTIVE: To assess the factors that predict operative mortality after intestinal infarction, and show what effect referral patterns have on mortality. DESIGN: Retrospective study. SETTING: Two university departments of surgery, France. SUBJECTS: 144 patients with intestinal infarctions operated on between January 1980 and August 1995. INTERVENTIONS: Univariate and multivariate analyses. MAIN OUTCOME MEASURES: Operative mortality and the factors associated with it. RESULTS: Operative mortality was 67% (96/144) during the first 45 days postoperatively. The univariate analysis showed that age over 75 years (p=0.0002), female sex (p=0.007), the presence of shock (p < 0.0001), and referral from cardiovascular medical or surgical unit (p=0.01) were significantly associated with mortality. However, the multivariate analysis reduced these to extent of infarction (p=0.0001), the presence of shock (p=0.0002), age over 75 years (p=0.0001), and recent cardiac or vascular operation (p=0.03). CONCLUSIONS: The influence of referral pattern was related to previous cardiac or vascular operation, and the risk among women to the fact that their age was 10 years older than that of men. This study shows how the type of referral may explain the wide variations in reported mortality. To compare published series, care should be taken to avoid any selection bias.     

Postoperative pneumonia

Thoracic surgical patients are susceptible to pneumonia because of impaired systemic and lung host defenses. The incidence of pneumonia is higher with more extensive lung resections. Current prophylactic antibiotic therapy is based primarily on general surgical experience with emphasis on wound infection, not pneumonia. With expansion of indications for lung resection to include higher risk patients, there is a need to render antibiotic prophylaxis more specific to bacteria causative of pneumonia.     

Nosocomial pneumonia

A unique, symmetrical onychodystrophy is described in 18 dogs. A rather sudden onset of onychomadesis is followed by chronic onychodystrophy affecting all claws. Pain and lameness are recognized in half of the patients, but the dogs are healthy otherwise. Histopathologically, this disorder is characterized by hydropic and lichenoid interface dermatitis. Nine dogs were treated with a commercial, fatty-acid supplement and had good-to-excellent responses. Due to the clinicopathological characteristics of this disorder, the authors propose the name "symmetrical lupoid onychodystrophy."