Richard G. Wunderink

priate starting point for consultation by specialists. Substantial overlap exists among the patients whom these guidelines address and those discussed in the recently published guidelines for health care-associated pneumonia (HCAP). Pneumonia in nonambulatory residents of nursing homes and other long-term care facilities epidemiologically mirrors hospital-acquired pneumonia and should be treated according to the HCAP guidelines. However, certain other patients whose conditions are included in the designation of HCAP are better served by management in accordance with CAP guidelines with concern for specific pathogens.

BACKGROUND: Community-acquired pneumonia is a leading infectious cause of hospitalization and death among U.S. adults. Incidence estimates of pneumonia confirmed radiographically and with the use of current laboratory diagnostic tests are needed. METHODS: We conducted active population-based surveillance for community-acquired pneumonia requiring hospitalization among adults 18 years of age or older in five hospitals in Chicago and Nashville. Patients with recent hospitalization or severe immunosuppression were excluded. Blood, urine, and respiratory specimens were systematically collected for culture, serologic testing, antigen detection, and molecular diagnostic testing. Study radiologists independently reviewed chest radiographs. We calculated population-based incidence rates of community-acquired pneumonia requiring hospitalization according to age and pathogen. RESULTS: From January 2010 through June 2012, we enrolled 2488 of 3634 eligible adults (68%). Among 2320 adults with radiographic evidence of pneumonia (93%), the median age of the patients was 57 years (interquartile range, 46 to 71); 498 patients (21%) required intensive care, and 52 (2%) died. Among 2259 patients who had radiographic evidence of pneumonia and specimens available for both bacterial and viral testing, a pathogen was detected in 853 (38%): one or more viruses in 530 (23%), bacteria in 247 (11%), bacterial and viral pathogens in 59 (3%), and a fungal or mycobacterial pathogen in 17 (1%). The most common pathogens were human rhinovirus (in 9% of patients), influenza virus (in 6%), and Streptococcus pneumoniae (in 5%). The annual incidence of pneumonia was 24.8 cases (95% confidence interval, 23.5 to 26.1) per 10,000 adults, with the highest rates among adults 65 to 79 years of age (63.0 cases per 10,000 adults) and those 80 years of age or older (164.3 cases per 10,000 adults). For each pathogen, the incidence increased with age. CONCLUSIONS: The incidence of community-acquired pneumonia requiring hospitalization was highest among the oldest adults. Despite current diagnostic tests, no pathogen was detected in the majority of patients. Respiratory viruses were detected more frequently than bacteria. (Funded by the Influenza Division of the National Center for Immunizations and Respiratory Diseases.).

BACKGROUND: Incidence estimates of hospitalizations for community-acquired pneumonia among children in the United States that are based on prospective data collection are limited. Updated estimates of pneumonia that has been confirmed radiographically and with the use of current laboratory diagnostic tests are needed. METHODS: We conducted active population-based surveillance for community-acquired pneumonia requiring hospitalization among children younger than 18 years of age in three hospitals in Memphis, Nashville, and Salt Lake City. We excluded children with recent hospitalization or severe immunosuppression. Blood and respiratory specimens were systematically collected for pathogen detection with the use of multiple methods. Chest radiographs were reviewed independently by study radiologists. RESULTS: From January 2010 through June 2012, we enrolled 2638 of 3803 eligible children (69%), 2358 of whom (89%) had radiographic evidence of pneumonia. The median age of the children was 2 years (interquartile range, 1 to 6); 497 of 2358 children (21%) required intensive care, and 3 (<1%) died. Among 2222 children with radiographic evidence of pneumonia and with specimens available for bacterial and viral testing, a viral or bacterial pathogen was detected in 1802 (81%), one or more viruses in 1472 (66%), bacteria in 175 (8%), and both bacterial and viral pathogens in 155 (7%). The annual incidence of pneumonia was 15.7 cases per 10,000 children (95% confidence interval [CI], 14.9 to 16.5), with the highest rate among children younger than 2 years of age (62.2 cases per 10,000 children; 95% CI, 57.6 to 67.1). Respiratory syncytial virus was more common among children younger than 5 years of age than among older children (37% vs. 8%), as were adenovirus (15% vs. 3%) and human metapneumovirus (15% vs. 8%). Mycoplasma pneumoniae was more common among children 5 years of age or older than among younger children (19% vs. 3%). CONCLUSIONS: The burden of hospitalization for children with community-acquired pneumonia was highest among the very young, with respiratory viruses the most commonly detected causes of pneumonia. (Funded by the Influenza Division of the National Center for Immunization and Respiratory Diseases.).

The most recent European guidelines and task force reports on hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) were published almost 10 years ago. Since then, further randomised clinical trials of HAP and VAP have been conducted and new information has become available. Studies of epidemiology, diagnosis, empiric treatment, response to treatment, new antibiotics or new forms of antibiotic administration and disease prevention have changed old paradigms. In addition, important differences between approaches in Europe and the USA have become apparent.The European Respiratory Society launched a project to develop new international guidelines for HAP and VAP. Other European societies, including the European Society of Intensive Care Medicine and the European Society of Clinical Microbiology and Infectious Diseases, were invited to participate and appointed their representatives. The Latin American Thoracic Association was also invited.A total of 15 experts and two methodologists made up the panel. Three experts from the USA were also invited (Michael S. Niederman, Marin Kollef and Richard Wunderink).Applying the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methodology, the panel selected seven PICO (population-intervention-comparison-outcome) questions that generated a series of recommendations for HAP/VAP diagnosis, treatment and prevention.

Human coronaviruses (HCoVs) have been considered to be relatively harmless respiratory pathogens in the past. However, after the outbreak of the severe acute respiratory syndrome (SARS) and emergence of the Middle East respiratory syndrome (MERS), HCoVs have received worldwide attention as important pathogens in respiratory tract infection. This review focuses on the epidemiology, pathogenesis and clinical characteristics among SARS-coronaviruses (CoV), MERS-CoV and other HCoV infections.