James Meek

Burden of Clostridium difficile Infection in the United States

BACKGROUND The magnitude and scope of Clostridium difficile infection in the United States continue to evolve. METHODS In 2011, we performed active population- and laboratory-based surveillance across 10 geographic areas in the United States to identify cases of C. difficile infection (stool specimens positive for C. difficile on either toxin or molecular assay in residents ≥ 1 year of age). Cases were classified as community-associated or health care-associated. In a sample of cases of C. difficile infection, specimens were cultured and isolates underwent molecular typing. We used regression models to calculate estimates of national incidence and total number of infections, first recurrences, and deaths within 30 days after the diagnosis of C. difficile infection. RESULTS A total of 15,461 cases of C. difficile infection were identified in the 10 geographic areas; 65.8% were health care-associated, but only 24.2% had onset during hospitalization. After adjustment for predictors of disease incidence, the estimated number of incident C. difficile infections in the United States was 453,000 (95% confidence interval [CI], 397,100 to 508,500). The incidence was estimated to be higher among females (rate ratio, 1.26; 95% CI, 1.25 to 1.27), whites (rate ratio, 1.72; 95% CI, 1.56 to 2.0), and persons 65 years of age or older (rate ratio, 8.65; 95% CI, 8.16 to 9.31). The estimated number of first recurrences of C. difficile infection was 83,000 (95% CI, 57,000 to 108,900), and the estimated number of deaths was 29,300 (95% CI, 16,500 to 42,100). The North American pulsed-field gel electrophoresis type 1 (NAP1) strain was more prevalent among health care-associated infections than among community-associated infections (30.7% vs. 18.8%, P<0.001). CONCLUSIONS C. difficile was responsible for almost half a million infections and was associated with approximately 29,000 deaths in 2011. (Funded by the Centers for Disease Control and Prevention.).

Lyme Disease Testing by Large Commercial Laboratories in the United States

BACKGROUND Laboratory testing is helpful when evaluating patients with suspected Lyme disease (LD). A 2-tiered antibody testing approach is recommended, but single-tier and nonvalidated tests are also used. We conducted a survey of large commercial laboratories in the United States to assess laboratory practices. We used these data to estimate the cost of testing and number of infections among patients from whom specimens were submitted. METHODS Large commercial laboratories were asked to report the type and volume of testing conducted nationwide in 2008, as well as the percentage of positive tests for 4 LD-endemic states. The total direct cost of testing was calculated for each test type. These data and test-specific performance parameters available in published literature were used to estimate the number of infections among source patients. RESULTS Seven participating laboratories performed approximately 3.4 million LD tests on approximately 2.4 million specimens nationwide at an estimated cost of

Association Between Use of Statins and Mortality Among Patients Hospitalized With Laboratory-Confirmed Influenza Virus Infections: A Multistate Study

492 million. Two-tiered testing accounted for at least 62% of assays performed; alternative testing accounted for <3% of assays. The estimated frequency of infection among patients from whom specimens were submitted ranged from 10% to 18.5%. Applied to the total numbers of specimens, this yielded an estimated 240 000 to 444 000 infected source patients in 2008. DISCUSSION LD testing is common and costly, with most testing in accordance with diagnostic recommendations. These results highlight the importance of considering clinical and exposure history when interpreting laboratory results for diagnostic and surveillance purposes.

Burden of seasonal influenza hospitalization in children, United States, 2003 to 2008.

BACKGROUND Statins may have anti-inflammatory and immunomodulatory effects that could reduce the risk of mortality from influenza virus infections. METHODS The Centers for Disease Control and Preventions Emerging Infections Program conducts active surveillance for persons hospitalized with laboratory-confirmed influenza in 59 counties in 10 states. We analyzed data for hospitalized adults during the 2007-2008 influenza season to evaluate the association between receiving statins and influenza-related death. RESULTS We identified 3043 patients hospitalized with laboratory-confirmed influenza, of whom 1013 (33.3%) received statins and 151 (5.0%) died within 30 days of their influenza test. Patients who received statins were more likely to be older, male, and white; to suffer from cardiovascular, metabolic, renal, and chronic lung disease; and to have been vaccinated against influenza that season. In a multivariable logistic regression model, administration of statins prior to or during hospitalization was associated with a protective odds of death (adjusted odds ratio, 0.59 [95% confidence interval, .38-.92]) when adjusting for age; race; cardiovascular, lung, and renal disease; influenza vaccination; and antiviral administration. CONCLUSIONS Statin use may be associated with reduced mortality in patients hospitalized with influenza.

Underreporting of lyme disease by connecticut physicians, 1992

OBJECTIVES To estimate the rates of hospitalization with seasonal influenza in children aged <18 years from a large, diverse surveillance area during 2003 to 2008. STUDY DESIGN Through the Emerging Infections Program Network, population-based surveillance for laboratory-confirmed influenza was conducted in 10 states, including 5.3 million children. Hospitalized children were identified retrospectively; clinicians made influenza testing decisions. Data collected from the hospital record included demographics, medical history, and clinical course. Incidence rates were calculated with census data. RESULTS The highest hospitalization rates occurred in children aged <6 months (seasonal range, 9-30/10 000 children), and the lowest rates occurred in children aged 5 to 17 years (0.3-0.8/10 000). Overall, 4015 children were hospitalized, 58% of whom were identified with rapid diagnostic tests alone. Forty percent of the children who were hospitalized had underlying medical conditions; asthma (18%), prematurity (15% of children aged <2 years), and developmental delay (7%) were the most common. Severe outcomes included intensive care unit admission (12%), respiratory failure (5%), bacterial coinfection (2%), and death (0.5%). CONCLUSIONS Influenza-associated hospitalization rates varied by season and age and likely underestimate true rates because many hospitalized children are not tested for influenza. The proportion of children with severe outcomes was substantial across seasons. Quantifying incidence of influenza hospitalization and severe outcomes is critical to defining disease burden.

Adult Hospitalizations for Laboratory-Positive Influenza during the 2005–2006 through 2007–2008 Seasons in the United States

To determine the magnitude of underreporting of Lyme disease, a random sample of Connecticut physicians was surveyed in 1993. The magnitude of underreporting was assessed by comparing physician estimates of Lyme disease diagnoses with reports of Lyme disease sent by physicians to the Connecticut Lyme disease surveillance system. Complete questionnaires were returned by 59 percent (412/698) of those surveyed. Of the 224 respondents who indicated that they had made a diagnosis of Lyme disease in 1992, only 56 (25 percent) reported a case of Lyme disease that year. Survey results suggested that, at best, only 16 percent of Lyme disease cases were reported in 1992. Physician underreporting of Lyme disease underestimates the public health impact of Lyme disease.

The Emergence of Another Tickborne Infection in the 12-Town Area around Lyme, Connecticut: Human Granulocytic Ehrlichiosis

BACKGROUND Rates of influenza-associated hospitalizations in the United States have been estimated using modeling techniques with data from pneumonia and influenza hospitalization discharge diagnoses, but they have not been directly estimated from laboratory-positive cases. METHODS We calculated overall, age-specific, and site-specific rates of laboratory-positive, influenza-associated hospitalization among adults and compared demographic and clinical characteristics and outcomes of hospitalized cases by season with use of data collected by the Emerging Infections Program Network during the 2005-2006 through 2007-2008 influenza seasons. RESULTS Overall rates of adult influenza-associated hospitalization per 100,000 persons were 9.9 during the 2005-2006 season, 4.8 during the 2006-2007 season, and 18.7 during the 2007-2008 season. Rates of hospitalization varied by Emerging Infections Program site and increased with increasing age. Higher overall and age-specific rates of hospitalization were observed during influenza A (H3) predominant seasons and during periods of increased circulation of influenza B. More than 80% of hospitalized persons each season had > or =1 underlying medical condition, including chronic cardiovascular and metabolic diseases. CONCLUSIONS Rates varied by season, age, geographic location, and type/subtype of circulating influenza viruses. Influenza-associated hospitalization surveillance is essential for assessing the relative severity of influenza seasons over time and the burden of influenza-associated complications.

Guillain-Barré Syndrome During the 2009–2010 H1N1 Influenza Vaccination Campaign: Population-based Surveillance Among 45 Million Americans

Human granulocytic ehrlichiosis (HGE) is an emerging tickborne infection, increasingly recognized in areas in which Lyme disease is endemic, but there are few data on the incidence of HGE. Prospective population-based surveillance was conducted in the 12-town area around Lyme, Connecticut, by means of both active and passive methods, from April through November of 1997, 1998, and 1999. Five hundred thirty-seven residents presenting to their primary care provider with an acute febrile illness suggestive of HGE were identified. Of these, 137 (26%) had laboratory evidence (by indirect fluorescent antibody staining or polymerase chain reaction) of HGE; 89 were confirmed cases, and 48 were probable cases. The incidence of confirmed HGE was 31 cases/100,000 in 1997, 51 cases/100,000 in 1998, and 24 cases/100,000 in 1999. A subset of sera was tested by use of immunoblot assays, and results were in agreement with indirect fluorescent antibody methods for 86% of samples analyzed. Thus, HGE is an important cause of morbidity and is now the second most common tickborne infection in southeastern Connecticut.

Peridomestic Lyme disease prevention: results of a population-based case-control study.

Because of widespread distribution of the influenza A (H1N1) 2009 monovalent vaccine (pH1N1 vaccine) and the prior association between Guillain-Barré syndrome (GBS) and the 1976 H1N1 influenza vaccine, enhanced surveillance was implemented to estimate the magnitude of any increased GBS risk following administration of pH1N1 vaccine. The authors conducted active, population-based surveillance for incident cases of GBS among 45 million persons residing at 10 Emerging Infections Program sites during October 2009-May 2010; GBS was defined according to published criteria. The authors determined medical and vaccine history for GBS cases through medical record review and patient interviews. The authors used vaccine coverage data to estimate person-time exposed and unexposed to pH1N1 vaccine and calculated age- and sex-adjusted rate ratios comparing GBS incidence in these groups, as well as age- and sex-adjusted numbers of excess GBS cases. The authors received 411 reports of confirmed or probable GBS. The rate of GBS immediately following pH1N1 vaccination was 57% higher than in person-time unexposed to vaccine (adjusted rate ratio = 1.57, 95% confidence interval: 1.02, 2.21), corresponding to 0.74 excess GBS cases per million pH1N1 vaccine doses (95% confidence interval: 0.04, 1.56). This excess risk was much smaller than that observed during the 1976 vaccine campaign and was comparable to some previous seasonal influenza vaccine risk assessments.

Clostridium difficile Infection Among Children Across Diverse US Geographic Locations

BACKGROUND Peridomestic Lyme disease-prevention initiatives promote personal protection, landscape modification, and chemical control. PURPOSE A 32-month prospective age- and neighborhood-matched case-control study was conducted in Connecticut to evaluate the effects of peridomestic prevention measures on risk of Lyme disease. METHODS The study was conducted in 24 disease-endemic Connecticut communities from 2005 to 2007. Subjects were interviewed by telephone using a questionnaire designed to elicit disease-prevention measures during the month prior to the case onset of erythema migrans. Data were analyzed in 2008 by conditional logistic regression. Potential confounders, such as occupational/recreational exposures, were examined. RESULTS Between April 2005 and November 2007, interviews were conducted with 364 participants with Lyme disease, and 349 (96%) were matched with a suitable control. Checking for ticks within 36 hours of spending time in the yard at home was protective against Lyme disease (OR=0.55; 95% CI=0.32, 0.94). Bathing within 2 hours after spending time in the yard was also protective (OR=0.42; 95% CI=0.23, 0.78). Fencing of any type or height in the yard, whether it was contiguous or not, was protective (OR=0.54; 95% CI=0.33, 0.90). No other landscape modifications or features were significantly protective against Lyme disease. CONCLUSIONS The results of this study suggest that practical activities such as checking for ticks and bathing after spending time in the yard may reduce the risk of Lyme disease in regions where peridomestic risk is high. Fencing did appear to protect against infection, but the mechanism of its protection is unclear.