Biomedical subjects

R Heffernan

Publications and source records attributed to R Heffernan.

7 recordsLinked to original sources

PubMed2005

Monitoring over-the-counter medication sales for early detection of disease outbreaks--New York City.

INTRODUCTION: Over-the-counter (OTC) medications are frequently used during the initial phase of illness, and increases in their sales might serve as an early indicator of communitywide disease outbreaks. Since August 2002, the New York City (NYC) Department of Health and Mental Hygiene (DOHMH) has tracked OTC medication sales to enhance detection of natural and intentional infectious disease outbreaks. OBJECTIVES: This report describes the surveillance system and presents results from retrospective analyses and a comparison between citywide trends in OTC medication sales and emergency department (ED) visits. METHODS: Sales data transmitted daily to DOHMH are categorized into two groups: influenza-like illness (ILI), which includes cough and influenza medications, and gastrointestinal illness (GI), which includes major brand and generic antidiarrheals. Cyclical, linear regression models were used to identify significant (p<0.05) increases in the daily ratio of ILI to analgesics sales (analgesics are used as a denominator in the absence of total sales). Daily and weekly average ratios of GI to analgesic sales were analyzed. Citywide trends in OTC ILI and GI medication sales were compared with ED visits for fever/influenza and diarrhea syndromes. RESULTS: Citywide ILI drug sales were highest during annual influenza epidemics and elevated during spring and fall allergy seasons, similar to trends in the ED fever/influenza syndrome. ILI sales did not consistently provide earlier warning than the ED system of communitywide influenza. GI drug sales increased during the fall and peaked during early winter and after the blackout of August 2003. Unlike ED diarrheal visits, GI medication sales did not substantially increase during late winter (February-March). CONCLUSION: Citywide OTC medication sales can provide indications of communitywide illness, including annual influenza epidemics. Antidiarrheal medication sales were more sensitive to increases in GI caused by norovirus and influenza than illness caused by rotavirus. OTC medication sales can be considered as an adjunct syndromic surveillance system but might not be as sensitive as ED systems.

Commerce↗

PubMed2005

Three years of emergency department gastrointestinal syndromic surveillance in New York City: what have we found?

BACKGROUND: Use of syndromic surveillance as a tool to detect outbreaks and potential biologic or chemical terrorist attacks is increasing. Evaluating health departments' use of syndromic surveillance is necessary to determine the value of this methodology. METHODS: Syndromic surveillance signals detected by the New York City Department of Health and Mental Hygiene (DOHMH) during November 2001-August 2004 were reviewed for diarrhea and vomiting syndromes, the methods used to investigate such signals, and results of these investigations to determine if any unreported outbreaks were detected. Gastrointestinal (GI) outbreaks reported to DOHMH also were reviewed to understand why they were not detected by DOHMH's Emergency Department (ED) syndromic surveillance system. RESULTS: During the study period, ED surveillance generated 98 citywide and 138 spatial GI signals. Multiple outbreaks suspected to be caused by norovirus and rotavirus were identified, as well as a citywide increase in diarrheal illness. Of 98 citywide signals detected, 73 (75%) occurred during seasonal outbreaks. During the same period, 49 GI outbreaks were reported to DOHMH; none was detected simultaneously by ED surveillance. CONCLUSION: Only substantial, citywide syndromic signals were identified as outbreaks and routinely reported. GI outbreaks did not generate syndromic signals. Syndromic surveillance signals occur frequently, are difficult to investigate satisfactorily, and should be viewed as a supplement to, rather than a replacement for, well-maintained traditional surveillance systems that rely on strong ties between clinicians and public health authorities.

Disease Outbreaks↗

PubMed2004

Benchmark data and power calculations for evaluating disease outbreak detection methods.

INTRODUCTION: Early detection of disease outbreaks enables public health officials to implement immediate disease control and prevention measures. Computer-based syndromic surveillance systems are being implemented to complement reporting by physicians and other health-care professionals to improve the timeliness of disease-outbreak detection. Space-time disease-surveillance methods have been proposed as a supplement to purely temporal statistical methods for outbreak detection to detect localized outbreaks before they spread to larger regions. OBJECTIVE: The aims of this study were twofold: 1) to design and make available benchmark data sets for evaluating the statistical power of space-time early detection methods and 2) to evaluate the power of the prospective purely temporal and space-time scan statistics by applying them to the benchmark data sets at different parameter settings. METHODS: Simulated data sets based on the geography and population of New York City were created, including effects of outbreaks of varying size and location. Data sets with no outbreak effects were also created. Scan statistics were then run on these data sets, and the resulting power performances were analyzed and compared. RESULTS: The prospective space-time scan statistic performs well for a spectrum of outbreak models. By comparison, the prospective purely temporal scan statistic has higher power for detecting citywide outbreaks but lower power for detecting geographically localized outbreaks. CONCLUSIONS: The benchmark data sets created for this study can be used successfully for formal statistical power evaluations and comparisons. If an anomaly caused by an outbreak is local, purely temporal surveillance methods might be unable to detect it, in which case space-time methods would be necessary for early detection.

Benchmarking↗

PubMed2004

Field investigations of emergency department syndromic surveillance signals--New York City.

INTRODUCTION: The New York City (NYC) Department of Health and Mental Hygiene (DOHMH) has operated a syndromic surveillance system based on emergency department (ED) chief-complaint data since November 2001. This system was created for early detection of infectious-disease outbreaks, either natural or intentional. However, limited documentation exists regarding epidemiologic field investigations conducted in response to syndromic surveillance signals. OBJECTIVE: DOHMH conducted field investigations to characterize syndromic surveillance signals by person, place, and time and to determine whether signals represented true infectious-disease outbreaks. METHODS: A DOHMH physician reviews ED-based syndromic surveillance results daily to look for signals. When necessary, field investigations are conducted and consist of a review of the patient line list, telephone interviews with hospital staff, chart reviews, interviews with patients, and collection and testing of specimens. RESULTS: In November 2002, a series of citywide signals for diarrhea and vomiting syndromes, which coincided with institutional outbreaks consistent with viral gastroenteritis, prompted DOHMH to send mass e-mail notification to NYC ED directors and institute collection of stool specimens. Three of four specimens collected were positive for norovirus. In December 2002, DOHMH investigated why an ED syndromic signal was not generated after 15 ill patients were transferred to a participating ED during a gastrointestinal outbreak at a nursing home. Field investigation revealed varying chief complaints, multiple dates of ED visits, and a coding error in a complementary DOHMH syndromic system, and confirmed a seasonal norovirus outbreak. During March 2003, the system generated a 4-day citywide respiratory signal and a simultaneous 1-day hospital-level fever signal in a predominantly Asian community. In those instances, epidemiologic investigation provided reassurance that severe acute respiratory syndrome was not present. CONCLUSION: Detailed field investigations of syndromic signals can identify the etiology of signals and determine why a given syndromic surveillance system failed to detect an outbreak captured through traditional surveillance. Validation of the utility of syndromic surveillance to detect infectious-disease outbreaks is necessary to justify allocating resources for this new public health tool.

Communicable Diseases, Emerging↗

PubMed2001

Effect of tick removal on transmission of Borrelia burgdorferi and Ehrlichia phagocytophila by Ixodes scapularis nymphs.

The effect of feeding duration on pathogen transmission was studied for individual ticks infected with either laboratory or field strains of the Lyme disease spirochete Borrelia burgdorferi and field strains of Ehrlichia phagocytophila, an agent of human granulocytic ehrlichiosis. Infected nymphal Ixodes scapularis were allowed to feed individually on mice, and equal numbers were removed at 24-h intervals for < or =96 h. Mice were assayed for infection by culture, serologic testing, and polymerase chain reaction (PCR) analysis. Fed ticks were assayed by culture or PCR analysis. Transmission of B. burgdorferi did not occur during the first 24 h among 66 attempts, with maximum transmission occurring between 48 and 72 h. A model estimating the probability of infection from individual ticks removed by patients in a Lyme disease-endemic area yielded an overall probability of 4.6%. Infected I. scapularis nymphs transmitted E. phagocytophila within 24 h in 2 of 3 attempts, which indicates that daily tick removal may not be adequate to prevent human infection with this agent.

Animals↗

PubMed1996

HIV risk behaviors among adolescents at a sexually transmitted disease clinic in New York City.

PURPOSE: The purpose of this study was to describe human immunodeficiency virus (HIV)-associated risk behaviors among adolescents attending a clinic for the treatment of sexually transmitted disease in New York City. METHODS: A total of 4,585 volunteers were interviewed and HIV-tested, including 456 adolescents (aged 13-19 years), of whom 220 were women (48%) and 236 men (52%). RESULTS: Fewer than 1% of the 456 adolescents said they injected drugs. Unprotected vaginal sex was the most common sexual behavior, with 93% of adolescents reporting "always" having vaginal sex, and 57% "rarely or never" using condoms. Anal sex was reported by 18%. Twenty percent of adolescent men had paid for sex, compared to just 1% of women, whereas 3% of men and 4% of women had traded sex for money or drugs. Nine women and three men tested HIV seropositive. All three HIV-positive men reported having had receptive anal sex with men. Among women, HIV seropositivity was most strongly associated with crack cocaine use and trading sex for money or drugs. CONCLUSIONS: HIV prevalence was high, with most infections owing to sexual transmission rather than intravenous drugs. The increased risk of HIV infection in adolescent women was associated with high-risk sex related to crack use and the exchange of sex for money or drugs.

Adolescent↗

PubMedDate not supplied

Laboratory survey of drug-resistant Streptococcus pneumoniae in New York City, 1993-1995.

Wide geographic variation in the prevalence of drug-resistant Streptococcus pneumoniae demonstrates the importance of tracking antimicrobial resistance locally. This survey of hospital microbiology laboratories in New York City found that penicillin resistance (MIC > or = 2.0 micrograms/ml) increased from 1.5% of S. pneumoniae isolates in 1993 to 6.3% in 1995 and that in 1995, one-third of isolates nonsusceptible to penicillin (MIC > or = 0.1 microgram/ml) were also nonsusceptible to an extended-spectrum cephalosporin (MIC > or = 1 microgram/ml).

Data Collection↗