Ken Komatsu

Health Care–Associated Measles Outbreak in the United States After an Importation: Challenges and Economic Impact

BACKGROUND On 12 February 2008, an infected Swiss traveler visited hospital A in Tucson, Arizona, and initiated a predominantly health care-associated measles outbreak involving 14 cases. We investigated risk factors that might have contributed to health care-associated transmission and assessed outbreak-associated hospital costs. METHODS Epidemiologic data were obtained by case interviews and review of medical records. Health care personnel (HCP) immunization records were reviewed to identify non-measles-immune HCP. Outbreak-associated costs were estimated from 2 hospitals. RESULTS Of 14 patients with confirmed cases, 7 (50%) were aged ≥ 18 years, 4 (29%) were hospitalized, 7 (50%) acquired measles in health care settings, and all (100%) were unvaccinated or had unknown vaccination status. Of the 11 patients (79%) who had accessed health care services while infectious, 1 (9%) was masked and isolated promptly after rash onset. HCP measles immunity data from 2 hospitals confirmed that 1776 (25%) of 7195 HCP lacked evidence of measles immunity. Among these HCPs, 139 (9%) of 1583 tested seronegative for measles immunoglobulin G, including 1 person who acquired measles. The 2 hospitals spent US

An Epidemic of Coccidioidomycosis in Arizona Associated with Climatic Changes, 1998–2001

799,136 responding to and containing 7 cases in these facilities. CONCLUSIONS Suspecting measles as a diagnosis, instituting immediate airborne isolation, and ensuring rapidly retrievable measles immunity records for HCPs are paramount in preventing health care-associated spread and in minimizing hospital outbreak-response costs.

Gastrointestinal Basidiobolomycosis in Arizona: Clinical and Epidemiological Characteristics and Review of the Literature

BACKGROUND Reports of coccidioidomycosis cases in Arizona have increased substantially. We investigated factors associated with the increase. METHODS We analyzed the National Electronic Telecommunications System for Surveillance (NETSS) data from 1998 to 2001 and used Geographic Information Systems (GIS) to map high-incidence areas in Maricopa County. Poisson regression analysis was performed to assess the effect of climatic and environmental factors on the number of monthly cases; a model was developed and tested to predict outbreaks. RESULTS The overall incidence in 2001 was 43 cases/100,000 population, a significant (P<.01, test for trend) increase from 1998 (33 cases/100,000 population); the highest age-specific rate was in persons > or =65 years old (79 cases/100,000 population in 2001). Analysis of NETSS data by season indicated high-incidence periods during the winter (November-February). GIS analysis showed that the highest-incidence areas were in the periphery of Phoenix. Multivariable Poisson regression modeling revealed that a combination of certain climatic and environmental factors were highly correlated with seasonal outbreaks (R2=0.75). CONCLUSIONS Coccidioidomycosis in Arizona has increased. Its incidence is driven by seasonal outbreaks associated with environmental and climatic changes. Our study may allow public-health officials to predict seasonal outbreaks in Arizona and to alert the public and physicians early, so that appropriate preventive measures can be implemented.

Coccidioidomycosis in Arizona: Increase in Incidence from 1990 to 1995

Gastrointestinal basidiobolomycosis (GIB) is an unusual fungal infection that is rarely reported in the medical literature. From April 1994 through May 1999, 7 cases of GIB occurred in Arizona, 4 from December 1998 through May 1999. We reviewed the clinical characteristics of the patients and conducted a case-control study to generate hypotheses about potential risk factors. All patients had histopathologic signs characteristic of basidiobolomycosis. Five patients were male (median age, 52 years; range, 37--59 years) and had a history of diabetes mellitus (in 3 patients), peptic ulcer disease (in 2), or pica (in 1). All patients underwent partial or complete surgical resection of the infected portions of their gastrointestinal tracts, and all received itraconazole postoperatively for a median of 10 months (range, 3--19 months). Potential risk factors included prior ranitidine use and longer residence in Arizona. GIB is a newly emerging infection that causes substantial morbidity and diagnostic confusion. Further studies are needed to better define its risk factors and treatment.

A Multistate Outbreak of Escherichia coli O157:H7 Infection Linked to Consumption of Beef Tacos at a Fast-Food Restaurant Chain

The number of cases of coccidioidomycosis (incidence) reported to the Arizona Department of Health Services increased from 255 (7.0 per 100,000 population) in 1990 to 623 (14.9 per 100,000 population) in 1995 (P < .001). Four counties in the south central region of the state, which contained 80% of the states population, had the largest increase and accounted for 95% of all cases in 1995. Cases in persons aged 65 years or older and men were reported more frequently (for both, P < .001). During 1995, 890 patients were discharged from Arizona hospitals with a diagnosis of coccidioidomycosis. Rates of hospitalization were greater among persons aged 55 years or older, men, and African-American (for all three, P < .01). Of the hospitalized patients, 48 died, and 12 (25%) of these patients had a concurrent diagnosis of human immunodeficiency virus infection. These data demonstrate that coccidioidomycosis is a growing health problem in Arizona.

Ontology-enhanced automatic chief complaint classification for syndromic surveillance

We investigated a multistate outbreak of Escherichia coli O157:H7 infections. Isolates from 13 case patients from California, Nevada, and Arizona were matched by pulsed-field gel electrophoresis subtyping. Five case patients (38%) were hospitalized, and 3 (23%) developed hemolytic uremic syndrome; none died. The median age was 12 years (range, 2-75 years), and 10 (77%) were female. Case-control studies found an association between illness and eating beef tacos at a national Mexican-style fast-food restaurant chain (88% of cases versus 38% of controls; matched OR, undefined; 95% confidence interval, 1.49 to infinity; P=.009). A trace-back investigation implicated an upstream supplier of beef, but a farm investigation was not possible. This outbreak illustrates the value of employing hospital laboratory-based surveillance to detect local clusters of infections and the effectiveness of using molecular subtyping to identify geographically dispersed outbreaks. The outbreak investigation also highlights the need for a more efficient tracking system for food products.

Risk Factors for Fatal Outcome From Rocky Mountain Spotted Fever in a Highly Endemic Area—Arizona, 2002–2011

Emergency department free-text chief complaints (CCs) are a major data source for syndromic surveillance. CCs need to be classified into syndromic categories for subsequent automatic analysis. However, the lack of a standard vocabulary and high-quality encodings of CCs hinder effective classification. This paper presents a new ontology-enhanced automatic CC classification approach. Exploiting semantic relations in a medical ontology, this approach is motivated to address the CC vocabulary variation problem in general and to meet the specific need for a classification approach capable of handling multiple sets of syndromic categories. We report an experimental study comparing our approach with two popular CC classification methods using a real-world dataset. This study indicates that our ontology-enhanced approach performs significantly better than the benchmark methods in terms of sensitivity, F measure, and F2 measure.

Intelligence and Security Informatics: Biosurveillance

BACKGROUND Rocky Mountain spotted fever (RMSF) is a disease that now causes significant morbidity and mortality on several American Indian reservations in Arizona. Although the disease is treatable, reported RMSF case fatality rates from this region are high (7%) compared to the rest of the nation (<1%), suggesting a need to identify clinical points for intervention. METHODS The first 205 cases from this region were reviewed and fatal RMSF cases were compared to nonfatal cases to determine clinical risk factors for fatal outcome. RESULTS Doxycycline was initiated significantly later in fatal cases (median, day 7) than nonfatal cases (median, day 3), although both groups of case patients presented for care early (median, day 2). Multiple factors increased the risk of doxycycline delay and fatal outcome, such as early symptoms of nausea and diarrhea, history of alcoholism or chronic lung disease, and abnormal laboratory results such as elevated liver aminotransferases. Rash, history of tick bite, thrombocytopenia, and hyponatremia were often absent at initial presentation. CONCLUSIONS Earlier treatment with doxycycline can decrease morbidity and mortality from RMSF in this region. Recognition of risk factors associated with doxycycline delay and fatal outcome, such as early gastrointestinal symptoms and a history of alcoholism or chronic lung disease, may be useful in guiding early treatment decisions. Healthcare providers should have a low threshold for initiating doxycycline whenever treating febrile or potentially septic patients from tribal lands in Arizona, even if an alternative diagnosis seems more likely and classic findings of RMSF are absent.

Modifiable Risk Factors for West Nile Virus Infection during an Outbreak—Arizona, 2010

Long Papers.- Early Outbreak Detection Using an Automated Data Feed of Test Orders from a Veterinary Diagnostic Laboratory.- Chinese Chief Complaint Classification for Syndromic Surveillance.- Incorporating Geographical Contacts into Social Network Analysis for Contact Tracing in Epidemiology: A Study on Taiwan SARS Data.- A Model for Characterizing Annual Flu Cases.- Population Dynamics in the Elderly: The Need for Age-Adjustment in National BioSurveillance Systems.- Data Classification for Selection of Temporal Alerting Methods for Biosurveillance.- High Performance Computing for Disease Surveillance.- Towards Real Time Epidemiology: Data Assimilation, Modeling and Anomaly Detection of Health Surveillance Data Streams.- Algorithm Combination for Improved Performance in Biosurveillance Systems.- Decoupling Temporal Aberration Detection Algorithms for Enhanced Biosurveillance.- Assessing Seasonal Variation in Multisource Surveillance Data: Annual Harmonic Regression.- A Study into Detection of Bio-Events in Multiple Streams of Surveillance Data.- A Web-Based System for Infectious Disease Data Integration and Sharing: Evaluating Outcome, Task Performance Efficiency, User Information Satisfaction, and Usability.- Public Health Affinity Domain: A Standards-Based Surveillance System Solution.- The Influenza Data Summary: A Prototype Application for Visualizing National Influenza Activity.- Global Foot-and-Mouth Disease Surveillance Using BioPortal.- Utilization of Predictive Mathematical Epidemiological Modeling in Crisis Preparedness Exercises.- Short Papers.- Ambulatory e-Prescribing: Evaluating a Novel Surveillance Data Source.- Detecting the Start of the Flu Season.- Syndromic Surveillance for Early Detection of Nosocomial Outbreaks.- A Bayesian Biosurveillance Method That Models Unknown Outbreak Diseases.- Spatial Epidemic Patterns Recognition Using Computer Algebra.- Detecting Conserved RNA Secondary Structures in Viral Genomes: The RADAR Approach.- Extended Abstracts.- Gemina: A Web-Based Epidemiology and Genomic Metadata System Designed to Identify Infectious Agents.- Internet APRS Data Utilization for Biosurveillance Applications.

Concurrent Outbreaks of St. Louis Encephalitis Virus and West Nile Virus Disease - Arizona, 2015.

West Nile virus (WNV) is the leading cause of mosquito-borne disease in the United States; however, risk factors for infection are poorly defined. We performed a case-control study to identify modifiable risk factors for WNV infection. Case-patients (N = 49) had laboratory evidence of recent WNV infection, whereas control-subjects (N = 74) had negative WNV serology. We interviewed participants, surveyed households, and assessed environmental data. WNV infection was associated with living in or near Water District X within Gilbert Township (adjusted odds ratio [aOR] 5.2; 95% confidence interval [95% CI] = 1.5-18.1), having water-holding containers in their yard (aOR 5.0; 95% CI = 1.5-17.3), and not working or attending school outside the home (aOR 2.4; 95% CI = 1.1-5.5). During this outbreak, WNV infection was likely primarily acquired peri-domestically with increased risk associated with potential mosquito larval habitats around the home and neighborhood.