J. Pekka Nuorti

Antibiotic prescription rates for acute respiratory tract infections in US ambulatory settings.

CONTEXT During the 1990s, antibiotic prescriptions for acute respiratory tract infection (ARTI) decreased in the United States. The sustainability of those changes is unknown. OBJECTIVE To assess trends in antibiotic prescriptions for ARTI. DESIGN, SETTING, AND PARTICIPANTS The National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey data (1995-2006) were used to examine trends in antibiotic prescription rates by antibiotic indication and class. Annual survey data and census denominators were combined in 2-year intervals for rate calculations. MAIN OUTCOME MEASURES National annual visit rates and antibiotic prescription rates for ARTI, including otitis media (OM) and non-ARTI. RESULTS Among children younger than 5 years, annual ARTI visit rates decreased by 17% (95% confidence interval [CI], 9%-24%), from 1883 per 1000 population in 1995-1996 to 1560 per 1000 population in 2005-2006, primarily due to a 33% (95% CI, 22%-43%) decrease in OM visit rates (950 to 634 per 1000 population, respectively). This decrease was accompanied by a 36% (95% CI, 26%-45%) decrease in ARTI-associated antibiotic prescriptions (1216 to 779 per 1000 population). Among persons aged 5 years or older, ARTI visit rates remained stable but associated antibiotic prescription rates decreased by 18% (95% CI, 6%-29%), from 178 to 146 per 1000 population. Antibiotic prescription rates for non-OM ARTI for which antibiotics are rarely indicated decreased by 41% (95% CI, 22%-55%) and 24% (95% CI, 10%-37%) among persons younger than 5 years and 5 years or older, respectively. Overall, ARTI-associated prescription rates for penicillin, cephalosporin, and sulfonamide/tetracycline decreased. Prescription rates for azithromycin increased and it became the most commonly prescribed macrolide for ARTI and OM (10% of OM visits). Among adults, quinolone prescriptions increased. CONCLUSIONS Overall antibiotic prescription rates for ARTI decreased, associated with fewer OM visits in children younger than 5 years and with fewer prescriptions for ARTI for which antibiotics are rarely indicated. However, prescription rates for broad-spectrum antibiotics increased significantly.

Trends in Acute Otitis Media-Related Health Care Utilization by Privately Insured Young Children in the United States, 1997-2004

OBJECTIVE. The goal was to estimate the population effect of 7-valent pneumococcal conjugate vaccine on rates of acute otitis media-related ambulatory visits and antibiotic prescriptions for <2-year-old children enrolled in private insurance plans. METHODS. We performed a retrospective analysis of a defined population by using the 1997–2004 MarketScan databases, which included an average of >500000 person-years of observations for children <2 years of age. Trends in rates of International Classification of Diseases, Ninth Revision-coded ambulatory visits and antibiotic prescriptions attributable to acute otitis media were evaluated, and the national direct medical expenditures for these outcomes were estimated. RESULTS. In a comparison of 2004 with 1997–1999 (baseline period), rates of ambulatory visits and antibiotic prescriptions attributable to acute otitis media decreased from 2173 to 1244 visits per 1000 person-years (42.7% reduction) and from 1244 to 722 prescriptions per 1000 person-years (41.9% reduction), respectively. Total, estimated, national direct medical expenditures for acute otitis media-related ambulatory visits and antibiotic prescriptions for children <2 years of age decreased from an average of

National Impact of Universal Childhood Immunization With Pneumococcal Conjugate Vaccine on Outpatient Medical Care Visits in the United States

1.41 billion during 1997 to 1999 to

A Widespread Outbreak of Yersinia pseudotuberculosis O:3 Infection from Iceberg Lettuce

0.95 billion in 2004 (32.3% reduction). CONCLUSIONS. Acute otitis media-related health care utilization and associated antibiotic prescriptions for privately insured young children decreased more than expected (on the basis of efficacy estimates in prelicensure clinical trials) after the introduction of routine 7-valent pneumococcal conjugate vaccine immunization. Although other factors, such as clinical practice guidelines to reduce antibiotic use, might have contributed to the observed trend, 7-valent pneumococcal conjugate vaccine may play an important role in reducing the burden of acute otitis media, resulting in substantial savings in medical care costs.

Cost-effectiveness of Adult Vaccination Strategies Using Pneumococcal Conjugate Vaccine Compared With Pneumococcal Polysaccharide Vaccine

BACKGROUND. Since introduction of the heptavalent pneumococcal conjugate vaccine in the United States in 2000, rates of invasive pneumococcal disease have declined. However, the national impact of heptavalent pneumococcal conjugate vaccine on pneumonia and otitis media remains unknown. OBJECTIVES. We compared national rates of outpatient visits for pneumonia and otitis media in children before and after heptavalent pneumococcal conjugate vaccine introduction. METHODS. Rates of ambulatory visits for pneumococcal and nonspecific pneumonia, otitis media, and other acute respiratory infections were compared before (1994–1999) and after (2002–2003) heptavalent pneumococcal conjugate vaccine introduction using the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey. To evaluate vaccine effects while accounting for temporal variability, ratios of pneumococcal-related disease rates in children <2 years old (vaccine target population) and in children 3 to 6 years old (not routinely vaccinated) were evaluated using a Poisson regression analysis. For children <2 years old, the differences between observed and expected rates were the estimated vaccine effects. RESULTS. After the introduction of heptavalent pneumococcal conjugate vaccine, otitis media visit rates declined by 20% in children aged <2 years. This decline represented 246 fewer otitis media visits per 1000 children aged <2 years annually. There were no significant decreases in outpatient visit rates for pneumonia or other acute respiratory infections for children aged <2 years. CONCLUSIONS. After heptavalent pneumococcal conjugate vaccine introduction, national rates of otitis media visits declined significantly in children <2 years old. Persistence of this trend will produce a significant reduction of the otitis media burden and further enhance the cost-effectiveness of heptavalent pneumococcal conjugate vaccine.

An Outbreak of Gastrointestinal Illness and Erythema Nodosum from Grated Carrots Contaminated with Yersinia pseudotuberculosis

BACKGROUND The vehicles and sources of Yersinia pseudotuberculosis infection are unknown. In Finland, clinical microbiology laboratories routinely report Y. pseudotuberculosis isolations and submit isolates for serotype analysis. In October 1998, the number of serotype O:3 infections increased markedly. METHODS Case patients with culture-confirmed Y. pseudotuberculosis O:3 infection were identified by use of laboratory-based surveillance. We conducted a population-based case-control study. Healthy community control subjects were matched by age, sex, and postal code. Isolates were subtyped by pulsed-field gel electrophoresis (PFGE). RESULTS Nationwide, 47 case patients were identified (age range, 2-77 years; median, 19 years). One patient with bacteremia died; 5 underwent appendectomies. We enrolled 38 case patients and 76 control subjects in the case-control study. Seventy-one percent of case patients and 42% of control subjects reported having eaten iceberg lettuce (matched odds ratio, 3.8; 95% confidence interval, 1.3-9.4); a dose-response relationship was found for increasing frequency of consumption. Of the 27 isolates obtained from case patients and tested in the analysis, all had indistinguishable PFGE patterns. Four lunch cafeterias that had served iceberg lettuce were associated with clusters of case patients. The lettuce was traced back to originating farms. CONCLUSIONS Iceberg lettuce was implicated as the vehicle of a widespread foodborne Y. pseudotuberculosis outbreak. Ongoing laboratory-based surveillance and serotype analysis were essential in the rapid detection of infection. Cases of yersiniosis, which appear to be sporadic, may be part of unrecognized outbreaks caused by contaminated fresh produce.

Pneumococcal Carriage and Invasive Disease in Children Before Introduction of the 13-valent Conjugate Vaccine: Comparison With the Era Before 7-valent Conjugate Vaccine

CONTEXT The cost-effectiveness of 13-valent pneumococcal conjugate vaccine (PCV13) compared with 23-valent pneumococcal polysaccharide vaccine (PPSV23) among US adults is unclear. OBJECTIVE To estimate the cost-effectiveness of PCV13 vaccination strategies in adults. DESIGN, SETTING, AND PARTICIPANTS A Markov state-transition model, lifetime time horizon, societal perspective. Simulations were performed in hypothetical cohorts of US 50-year-olds. Vaccination strategies and effectiveness estimates were developed by a Delphi expert panel; indirect (herd immunity) effects resulting from childhood PCV13 vaccination were extrapolated based on observed PCV7 effects. Data sources for model parameters included Centers for Disease Control and Prevention Active Bacterial Core surveillance, National Hospital Discharge Survey and Nationwide Inpatient Sample data, and the National Health Interview Survey. MAIN OUTCOME MEASURES Pneumococcal disease cases prevented and incremental costs per quality-adjusted life-year (QALY) gained. RESULTS In the base case scenario, administration of PCV13 as a substitute for PPSV23 in current recommendations (ie, vaccination at age 65 years and at younger ages if comorbidities are present) cost

Invasive Group B Streptococcal Infections in Finland: A Population-based Study

28,900 per QALY gained compared with no vaccination and was more cost-effective than the currently recommended PPSV23 strategy. Routine PCV13 at ages 50 and 65 years cost

Internet use and epidemiologic investigation of gastroenteritis outbreak.

45,100 per QALY compared with PCV13 substituted in current recommendations. Adding PPSV23 at age 75 years to PCV13 at ages 50 and 65 years gained 0.00002 QALYs, costing

Economic evaluation of pneumococcal conjugate vaccination in Finland

496,000 per QALY gained. Results were robust in sensitivity analyses and alternative scenarios, except when low PCV13 effectiveness against nonbacteremic pneumococcal pneumonia was assumed or when greater childhood vaccination indirect effects were modeled. In these cases, PPSV23 as currently recommended was favored. CONCLUSION Overall, PCV13 vaccination was favored compared with PPSV23, but the analysis was sensitive to assumptions about PCV13 effectiveness against nonbacteremic pneumococcal pneumonia and the magnitude of potential indirect effects from childhood PCV13 on pneumococcal serotype distribution.