Andrew T. Pavia

Community-Acquired Pneumonia Requiring Hospitalization among U.S. Adults

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.).

Seasonal Influenza in Adults and Children—Diagnosis, Treatment, Chemoprophylaxis, and Institutional Outbreak Management: Clinical Practice Guidelines of the Infectious Diseases Society of America

Guidelines for the treatment of persons with influenza virus infection were prepared by an Expert Panel of the Infectious Diseases Society of America. The evidence-based guidelines encompass diagnostic issues, treatment and chemoprophylaxis with antiviral medications, and issues related to institutional outbreak management for seasonal (interpandemic) influenza. They are intended for use by physicians in all medical specialties with direct patient care, because influenza virus infection is common in communities during influenza season and may be encountered by practitioners caring for a wide variety of patients.

An Epidemiological Investigation of a Sustained High Rate of Pediatric Parapneumonic Empyema: Risk Factors and Microbiological Associations

We investigated the increasing incidence of pediatric empyema during the 1990s at Primary Childrens Medical Center in Salt Lake City. Of 540 children hospitalized with community-acquired bacterial pneumonia (CAP) who were discharged from 1 July 1993 through 1 July 1999, 153 (28.3%) had empyema. The annual population incidence of empyema increased during the study period from 1 to 5 cases per 100,000 population aged <19 years. Streptococcus pneumoniae was identified as the most common cause of CAP with or without empyema; serotype 1 accounted for 50% of the cases of pneumococcal empyema. Patients with empyema were more likely to be >3 years old, to have > or =7 days of fever, to have varicella, and to have received antibiotics and ibuprofen before admission to the hospital, compared with patients without empyema (P<.0001 for each factor). The increasing incidence of empyema was associated with infection due to S. pneumoniae serotype 1, outpatient treatment with certain antibiotics, ibuprofen use, and varicella.

Influenza estacional en adultos y niños—Diagnóstico, tratamiento, quimioprofilaxis y control de brotes institucionales: Guías de práctica clínica de la Sociedad de Enfermedades Infecciosas de Estados Unidos de América

Abstract Un Grupo de Expertos de la Sociedad de Enfermedades Infecciosas de los Estados Unidos de América elaboró las guias para el tratamiento de personas infectadas por el virus de la influenza. Estas guias basadas en datos y pruebas cientificas comprenden el diagnóstico, el tratamiento y la quimioprofilaxis con medicamentos antivirales, además de temas relacionados con el control de brotes de influenza estacional (interpandémicas) en ámbitos institucionales. Están destinadas a los médicos de todas las especialidades a cargo de la atención directa de pacientes porque los médicos generales que atienden una gran variedad de casos son los que se enfrentan con la influenza, frecuente en el ámbito comunitario durante la temporada de influenza.

Impact of the pneumococcal conjugate vaccine on pneumococcal parapneumonic empyema.

Background: Pediatric pneumococcal parapneumonic empyema (PPE) has become increasingly common. In the last decade, Utah has had one of the highest rates of PPE in the United States, 14/100,000 children, attributed primarily to Streptococcus pneumoniae serotype 1. Our objective was to describe the temporal trends in PPE in Utah before and after the availability of the 7-valent pneumococcal conjugate vaccine (PCV-7). Methods: The Intermountain Health Care (IHC) data warehouse was queried for all cases of empyema in children younger than 18 years, defined as International Classification of Diseases, 9th revision, Clinical Modification code 510.9, for the study period March 1996–June 2005. We also retrieved and serotyped all blood and pleural fluid isolates of S. pneumoniae from children younger than 18 years with a diagnosis of PPE at Primary Childrens Medical Center (PCMC) between March 1996 and June 2005. The pre-PCV-7 period (PRE) included 57 months (March 1996–December 2000) and the post-PCV-7 period (POST) included 54 months (January 2001–June 2005). Results: We identified 776 cases of pediatric empyema in the IHC system, and 478 (62%) were managed at PCMC. In the years 1996–2000, we managed a mean of 38 cases of empyema per year compared with 71.5 cases per year between 2001 and 2004 (P = 0.006). At PCMC, there were 295 cases of invasive pneumococcal disease (IPD), and 74 (25%) were PPE. During the PRE period, PPE represented 24 of 137 (17.5%) cases of IPD compared with 50 of 158 (32%) in the POST period (P = 0.008). One-half of the children with PPE required intensive care and 4 died. During the PRE and POST periods, PPE was most often caused by serotype 1 (46 and 34%, respectively), but in the POST period serogroups 3 (20%), and 19A (14%) were also prevalent. PPE in PCV-7-immunized children was caused exclusively by nonvaccine serotypes. Conclusions: PPE in the post-PCV-7 era is more common, representing one-third of the IPD in children in UT. PPE is associated with significant morbidity and mortality. Serotype 1 remains the most common cause of PPE, but serotypes 3 and 19A are emerging.

Temporal trends of invasive disease due to Streptococcus pneumoniae among children in the intermountain west : Emergence of nonvaccine serogroups

BACKGROUND Use of the heptavalent pneumococcal conjugate vaccine (PCV-7 [Prevnar]) has been associated with decreased a incidence of invasive pneumococcal disease (IPD) among children in the United States. METHODS Cases of IPD in children < 18 years of age insured by or receiving health care from Intermountain Health Care during 1996-2003 were identified. Isolates of S. pneumoniae from children with IPD treated at Primary Childrens Medical Center (PCMC; Salt Lake City, UT) during 1997-2003 were serogrouped. Temporal trends of IPD, serogroup distribution of pneumococci, and antibiotic resistance among pneumococci were analyzed. RESULTS A total of 1535 cases of IPD were identified. The rate of IPD decreased 27% after the introduction of PCV7. Among children with IPD who were cared for at PCMC, disease in 73% was caused by PCV7 serogroups in 1997-2000, compared with 50% in 2001-2003 (P < .001), and the percentage of isolates resistant to penicillin decreased from 34% in 1997-2000 to 22% in 2001-2003 (P = .04). The percentage of IPD cases that were empyema increased from 16% to 30% (P = .015), and the percentage of severe cases of IPD increased from 57% to 71% (P = .026). Children with IPD due to non-PCV7 serogroups were older, were more likely to have parapneumonic empyema, and had longer hospital stays. CONCLUSIONS The incidence of IPD in the IMW decreased by 27% after the introduction of the PCV7 vaccine. During the postvaccine period (2001-2003), there were significant decreases in the proportion of cases of IPD caused by PCV7 and antibiotic-resistant serogroups. These benefits were accompanied by a significant increase in the proportion of IPD cases due to non-PCV7 serogroups, with increases in the incidence of empyema and severe IPD.

Hemolytic-uremic syndrome during an outbreak of Escherichia coli O157:H7 infections in institutions for mentally retarded persons: Clinical and epidemiologic observations

PURPOSE To describe an outbreak of Escherichia coli O175:H7 infection resulting in a high rate of progression to hemolytic-uremic syndrome, and to attempt to identify predictors of and risk factors for progression. DESIGN Case-control study among employees and comparison of daily clinical features in two groups: infected residents with subsequent development of HUS and those who had no complications. SETTING Two institutions for retarded persons in Utah. PATIENTS Twenty residents with E. coli O157:H7 infection (13 culture confirmed, 2 probable, and 5 possible); HUS developed in 8, and 4 died. Thirty-one infected employees (3 with culture-confirmed, 6 with probable, and 22 with possible infection). MEASUREMENTS AND MAIN RESULTS In a case-control study among employees, infection was independently associated with eating ground beef from a single lot prepared at several barbecues and with close contact with a resident who had diarrhea. Five of eight residents in whom HUS developed had received trimethoprim-sulfamethoxazole, compared with none of seven who had no subsequent complications (p = 0.026); this finding may reflect antimicrobial treatment of patients with more severe illness. Compared with infected residents without complications, persons with HUS were younger (median age 13 vs 27 years, p = 0.043) and, by the third day of illness, had higher leukocyte counts (median 23.7 X 10(9)/L vs 9.1 X 10(9)/L, p = 0.018) and temperature (median 38.5 degrees C vs 37.0 degrees C, p = 0.016). Leukocytosis peaked on day 4, more than 24 hours before signs of HUS appeared. CONCLUSIONS Food-borne outbreaks of E. coli O157:H7 in institutions may have devastating effects. Leukocytosis and fever may precede and predict HUS in patients with E. coli O157:H7 infection.

Antibiotic Prescribing in Ambulatory Pediatrics in the United States

BACKGROUND: Antibiotics are commonly prescribed for children with conditions for which they provide no benefit, including viral respiratory infections. Broad-spectrum antibiotic use is increasing, which adds unnecessary cost and promotes the development of antibiotic resistance. OBJECTIVE: To provide a nationally representative analysis of antibiotic prescribing in ambulatory pediatrics according to antibiotic classes and diagnostic categories and identify factors associated with broad-spectrum antibiotic prescribing. PATIENTS AND METHODS: We used the National Ambulatory and National Hospital Ambulatory Medical Care surveys from 2006 to 2008, which are nationally representative samples of ambulatory care visits in the United States. We estimated the percentage of visits for patients younger than 18 years for whom antibiotics were prescribed according to antibiotic classes, those considered broad-spectrum, and diagnostic categories. We used multivariable logistic regression to identify demographic and clinical factors that were independently associated with broad-spectrum antibiotic prescribing. RESULTS: Antibiotics were prescribed during 21% of pediatric ambulatory visits; 50% were broad-spectrum, most commonly macrolides. Respiratory conditions accounted for >70% of visits in which both antibiotics and broad-spectrum antibiotics were prescribed. Twenty-three percent of the visits in which antibiotics were prescribed were for respiratory conditions for which antibiotics are not clearly indicated, which accounts for >10 million visits annually. Factors independently associated with broad-spectrum antibiotic prescribing included respiratory conditions for which antibiotics are not indicated, younger patients, visits in the South, and private insurance. CONCLUSIONS: Broad-spectrum antibiotic prescribing in ambulatory pediatrics is extremely common and frequently inappropriate. These findings can inform the development and implementation of antibiotic stewardship efforts in ambulatory care toward the most important geographic regions, diagnostic conditions, and patient populations.

Epidemiology, complications, and cost of hospitalization in children with laboratory-confirmed influenza infection

BACKGROUND. Influenza causes significant morbidity among children. Previous studies used indirect case ascertainment methods with little cost data. We sought to measure the burden of laboratory-confirmed influenza from hospitalized children. METHODS. We conducted a retrospective cohort study during 3 viral seasons at Primary Childrens Medical Center (Salt Lake City, UT). Children ≤18 years of age who were hospitalized with laboratory-confirmed influenza infection were included. Outcomes included hospitalization rates, complications including intensive care unit stays, mechanical ventilation, length of stay, and total hospital costs. RESULTS. A total of 325 children had hospitalizations attributable to influenza over 3 viral seasons: 28% <6 months of age, 33% between 6 and 23 months of age; and 39% >2 years of age; 37% had high-risk medical conditions. Population-based rates of hospitalization for Salt Lake County residents ranged from 6.3 to 252.7 per 100000 children. The highest rates were in children younger than 6 months, and rates decreased with increasing age. Forty-nine (15%) children had an ICU stay; 27 required mechanical ventilation, and half of these patients were >2 years of age. Total hospital cost for the cohort was

Viral Infections of the Lower Respiratory Tract: Old Viruses, New Viruses, and the Role of Diagnosis

2 million; 55% was accounted for by children >2 years of age. Length of stay and total hospital costs were significantly higher in all children >2 years of age compared with children <6 months of age and were comparable to all children 6 to 23 months of age. CONCLUSIONS. Proven influenza infection in children results in substantial hospital resource utilization and morbidity. Nationwide, the median hospital costs may total