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.

Use of oral ciprofloxacin in community-acquired pneumonia.

Twenty-five acutely ill patients, 21 men and 4 women aged 20-90 years (mean, 54 years) with acute community-acquired bacterial pneumonia, were treated with ciprofloxacin orally. The diagnosis of pneumonia was based on clinical and roentgenographic evidence of pulmonary infiltrate and a Gram stain of sputum demonstrating neutrophils and bacteria. Initially, 12 patients received 750 mg of ciprofloxacin orally every 12 hours for 3-6 days (mean, 3.8 days) followed by 500 mg of oral medication twice daily for 4-7 days (mean, 4.8 days). The remaining 13 patients received 500 mg of ciprofloxacin orally for 8-15 days (mean, 8.5 days). Treatment was successful in all patients (100%). No superinfections occurred, and there was no development of resistance. The drug was well tolerated and only moderate transient elevation of transaminase levels (serum glutamic-oxaloacetic transaminase and serum glutamine pyruvic transaminase) was noted in one patient.

Fatal Pasteurella haemolytica pneumonia in bighorn sheep after direct contact with clinically normal domestic sheep.

Six Rocky Mountain bighorn sheep were raised in captivity from birth (n = 5) or taken from the wild as a lamb (n = 1). After the bighorn sheep were in captivity for over a year, 6 clinically normal domestic sheep were placed on the 2 ha of pasture on which the bighorn sheep were kept. Nasal swab specimens were obtained from all sheep at the time the domestic sheep were introduced. Pasteurella haemolytica was isolated from swab specimens obtained from 4 of 6 domestic sheep, but not from specimens obtained from the bighorn sheep. All 6 bighorn sheep died of acute hemorrhagic pneumonia after exposure to domestic sheep. Death in the bighorn sheep occurred on days 4, 27, 27, 29, 36, or 71 after initial exposure to domestic sheep. Pasteurella haemolytica was isolated from respiratory tract tissue specimens of all bighorn sheep at the time of death. None of the domestic sheep were clinically ill during the study. At the end of the study, 3 of 6 domestic sheep were euthanatized, and at necropsy, P haemolytica was isolated from 2 of them. The most common serotypes in bighorn and domestic sheep were P haemolytica T-3 and A-2. Other serotypes isolated included P haemolytica A-1, A-9, and A-11 in bighorn sheep and A-1 in domestic sheep. On the basis of results of this study and of other reports, domestic sheep and bighorn sheep should not be managed in proximity to each other because of the potential fatal consequences in bighorn sheep.

Experimental contact transmission of Pasteurella haemolytica from clinically normal domestic sheep causing pneumonia in Rocky Mountain bighorn sheep.

Two Rocky Mountain bighorn lambs (Ovis canadensis canadensis) were held in captivity for 120 days before being housed with two domestic sheep. The lambs were clinically normal and had no Pasteurella spp. on nasal swab cultures. The domestic sheep were known to carry Pasteurella haemolytica biotype A in the nasal passages. After being in close contact for 19 days. P. haemolytica biotype A was cultured from nasal swabs of one of the bighorn lambs. By 26 days, both bighorn sheep developed coughs, were anorectic and became lethargic and nasal swabs yielded P. haemolytica biotype T, serotype 10. Twenty-nine days after contact, the lambs were necropsied and found to have extensive fibrinous bronchopneumonia. From affected tissues pure cultures of beta-hemolytic P. haemolytica biotype T, serotype 10 were grown. Both domestic sheep remained clinically normal and had no gross or microscopic lesions, but they carried the same P. haemolytica serotype in their tonsils. Behavioural observations gave no indication of stress in the bighorn lambs.

Nosocomial infections.

Hospital-acquired infections cause significant morbidity, mortality and expense. Surveillance and control programs are necessary to reduce the rate of these infections. Measures to control infection include handwashing, sterilization, use of sterile disposable items, closed urinary drainage, intravenous catheter care, non-touch dressing technique, proper care of respiratory equipment and perioperative chemoprophylaxis.

Nosocomial pneumonia in the intubated patient.

The intubated patient receiving mechanical ventilation is at high risk for nosocomial pneumonia. Epidemiologic data, pathogenic mechanisms, and risk factors for the development of nosocomial pneumonia are reviewed in this subset of patients. Exogenous and endogenous factors for bacterial colonization of the oropharynx are summarized with particular emphasis on the effects of bacterial overgrowth in the stomach. In addition, we review the role of respiratory therapy equipment in the pathogenesis of pneumonia. Overall fatality rates for patients receiving mechanical ventilation in an intensive care unit is approximately 40%. Patients who develop ventilator-associated pneumonia have fatality rates that exceed 50% and are more than two-fold higher than intubated patients without pneumonia. Measures for altering oropharyngeal colonization, reducing gastric colonization, and the use of sound infection control practices are cornerstones for the prevention of ventilator-associated pneumonia.

Prospective study of perinatal transmission of Chlamydia trachomatis.

During a five-year period, 262 (4.7%) of 5,531 pregnant women had positive cervical cultures for Chlamydia trachomatis, and 131 of their infants were followed up prospectively to ascertain the outcome of chlamydial exposure during the birth process. Culture-confirmed inclusion conjunctivitis of the newborn was seen in 23 (18%) of the infants. Chlamydial pneumonia was diagnosed in 21 (16%) of the infants at risk. Chlamydia trachomatis was recovered from 47 of the infants (36%), while 79 (60%) showed serologic evidence of infection. Subclinical rectal and vaginal infections were detected in 14% of infants at risk. In our population, 2.8% of newborn infants show serologic evidence of perinatal chlamydial infection and 1.4% develop either chlamydial pneumonia or conjunctivitis. Incidence rates of this magnitude indicate the need for programs aimed at preventing perinatal transmission of C trachomatis.

Bacteriology of hospital-acquired pneumonia.

Hospital-acquired pneumonia was studied prospectively for 3 1/2 years in a 549-bed facility with acute medical-surgical care wards, convalescent wards, and a chronic care unit. Bacteriological studies were limited to transtracheal aspirates, pleural fluid, and blood cultures. The predominant isolates in 159 patients were gram-negative bacilli (47%), anaerobic bacteria (35%), Staphylococcus aureus (31%), and Streptococcus pneumoniae (26%). Nearly half of all specimens yielded a polymicrobial flora with more than one potential pathogen. Distribution of pathogens was similar with analysis of all patients, including patients with a monomicrobial infection and patients with bacteremic pneumonia. The prevalence of cases and distribution of bacteria were similar for patients located on acute medical-surgical wards and those in the nursing home care unit. Nosocomial pneumonia was judged directly responsible for lethal outcome in 19% of patients and a contributing factor to death in another 13%.

Effects of environment on infection in burn patients.

Burn patients in an early cohort (n = 173) treated in an intensive care ward without separate enclosures were compared with a later cohort (n = 213) treated in a renovated unit with separate bed enclosures. The number of patients developing infection was significantly reduced in the late group. Observed mortality was compared with mortality predicted on the basis of burn size and age alone. Reduction in observed compared with predicted mortality, inapparent in the early group, was seen in the late group and was restricted to the subgroup of patients with predicted mortality of 25% to 75%, in which the observed mortality of 28.3% was less than the predicted mortality of 48.7%. The incidence of infected patients was reduced from 58.1% in the early cohort to 30.4% in the late cohort. In comparison of the early cohort with the late cohort, the overall proportion of patients with bacteremia was reduced from 20.1% to 9.4%, while the incidences of both pneumonia and burn wound invasion remained unchanged. Providencia and Pseudomonas species, endemic in the early cohort, were eliminated in the late cohort. Reduction of infection by environmental manipulation in burn patients was possible and was associated with improved survival.

Comparison of ceftazidime with cefamandole for therapy of community-acquired pneumonia.

Ceftazidime and cefamandole were compared in the treatment of pneumonia. The median MIC of ceftazidime for all Streptococcus pneumoniae (n = 17) and Haemophilus influenzae (n = 10) isolates was 0.125 microgram/ml. All other isolates were inhibited by less than 0.5 microgram of ceftazidime per ml, with the exception of a group B streptococcus (MIC = 4 micrograms/ml). Satisfactory clinical responses were observed in 91% (20 of 22) of cefamandole-treated patients and 85% (17 of 20) of ceftazidime-treated patients.

Emerging perspectives in management and prevention of infections of the respiratory tract in infants and children.

New products, new procedures, new information, and new legislation will have a significant impact on management and prevention of respiratory infections in children. Current areas of investigation include the changing epidemiology (increased number of children in day care), concern about morbidity of common infections (hearing impairment and effect on development of speech and language due to otitis media), and new modes of microbiologic diagnosis (antigen detection). New antimicrobial agents have wider spectrums of activity, increased concentrations in body fluids, and lesser toxicity than available drugs. New uses of old drugs are identified (value of erythromycin for Legionella pneumophila, Chlamydia trachomatis, and Mycoplasma pneumoniae). Increased usage of chemoprophylaxis for prevention of recurrences of acute otitis media follows publication of impressive results of recent studies. New conjugate polysaccharide vaccines are immunogenic in young infants. Finally, and of major importance to children, physicians, and manufacturers, is vaccine liability legislation, now in congressional committee.

Severe community-acquired pneumonia: factors influencing need of intensive care treatment and prognosis.

53 patients with community-acquired pneumonia requiring treatment in an Intensive Care Unit (ICU) were studied retrospectively. The majority of patients (77%) had some predisposing factor: illness, smoking or alcoholism. A cause of pneumonia was established in 53% of the cases; Streptococcus pneumoniae was the dominating pathogen. Immediate active treatment was required in 70% of the patients and 58% were treated with mechanical ventilation. The overall mortality was 25% (32% among patients treated with mechanical ventilation) and rose to 39% when a follow-up period of 3.25 years on average was included. A significantly higher mortality rate was seen among elderly patients and among those who were previously immunocompromised or who had a leukocyte count of less than or equal to 9 X 10(9)/l on admission to hospital. It is concluded that although the mortality rate was considerable among the 53 ICU-treated patients with severe community-acquired pneumonias, several were saved by intensive care treatment. Most of those who survived their pneumonia eventually recovered fully.