Anthrax as a Biological Weapon

103

Several models have been proposed for the dose-response function and the incubation period distribution for human inhalation anthrax. These models give very different predictions for the severity of a hypothetical bioterror attack, when an attack might be detected from clinical cases, the efficacy of medical intervention and the requirements for decontamination. Using data from the 1979 accidental atmospheric release of anthrax in Sverdlovsk, Russia, and limited nonhuman primate data, this paper eliminates two of the contending models and derives parameters for the other two, thereby narrowing the range of models that accurately predict the effects of human inhalation anthrax. Dose-response functions that exhibit a threshold for infectivity are contraindicated by the Sverdlovsk data. Dose-dependent incubation period distributions explain the 10-day median incubation period observed at Sverdlovsk and the 1-to 5-day incubation period observed in nonhuman primate experiments.bioterrorism ͉ dose-response function ͉ incubation period

mentioning

confidence: 99%

Sverdlovsk revisited: Modeling human inhalation anthrax

Wilkening

2006

103

“…A nthrax has been a scourge of humans and domesticated animals since ancient times, and its causative agent, Bacillus anthracis, has long been considered a weapon of biological warfare or terrorism (1,2). Spores of B. anthracis can survive indefinitely in a wide range of environments (3), and a relatively modest dose delivered to mammalian skin or lungs can result in cutaneous or inhalational anthrax, respectively (4-7).…”

mentioning

confidence: 99%

Mailborne transmission of anthrax: Modeling and implications

Webb

Blaser

2002

A mathematical model is developed to analyze the transmission of inhalational anthrax through the postal system by cross-contamination of mail. The model consists of state vectors describing the numbers of cross-contaminated letters generated, the numbers of anthrax spores on these letters, the numbers of resulting infections in recipients, and matrices of transition probabilities acting on these vectors. The model simulates the recent outbreak in the United States, and provides a general framework to investigate the potential impact of possible future outbreaks.A nthrax has been a scourge of humans and domesticated animals since ancient times, and its causative agent, Bacillus anthracis, has long been considered a weapon of biological warfare or terrorism (1, 2). Spores of B. anthracis can survive indefinitely in a wide range of environments (3), and a relatively modest dose delivered to mammalian skin or lungs can result in cutaneous or inhalational anthrax, respectively (4-7). Gastrointestinal anthrax also occurs in certain regions of the world (8), although inhalational anthrax is the most lethal form (9).Since October 2001, both inhalational and cutaneous cases of anthrax have been recognized in the United States (10, 11), after a hiatus of more than 20 years (12). Of the 22 cases reported to date (December 15, 2001), 11 have been cutaneous and 11 have been inhalational; 5 persons with inhalational anthrax have died, with a case fatality rate of 45%. All cases of inhalational anthrax have occurred in persons above 43 years of age (median 56 years, range 43 to 94; refs. 11 and 13). After a 1979 accident at a Soviet factory producing anthrax spores in Sverdlovsk, a city of 1.2 million people, 79 persons were reported to have developed inhalational anthrax, and 68 of these died (1). All of the cases were clustered in a single quadrant of the city and its outskirts, corresponding to the area downwind of the plume released from the factory. Despite the large number of persons of all ages potentially exposed to this plume, no cases were reported in persons Ͻ24 years old (1). Both the Russian accident (1) and the current U.S. cases (11, 13) suggest that older persons have increased risk for contracting inhalational anthrax after environmental exposure.Most of the current U.S. cases have been traced to letters heavily contaminated with anthrax spores that were sent through the U.S. mail (14). All strains recovered from mail and from clinical specimens reportedly have the same molecular fingerprint (14), indicating their dissemination from a single source. These mail-related cases have occurred among the intended recipients of the letters or others in their work environment (n ϭ 7), or among postal workers (n ϭ 11). In addition, there have been four other cases, two cutaneous, and two inhalational (both fatal) in elderly women, in which the victims appear unrelated to either the intended recipients or the postal milieu (11).We propose that these ''unrelated'' cases occurred as a result of their receiving mail that h...

“…This release resulted in at least 79 cases of anthrax infection and 68 documented deaths (3,5). According to the pathologists who made the diagnosis for 42 autopsies, healthy people died within 1-4 days from contracting the bacteria (6).…”

Section: Historical and Current Biological Outbreaksmentioning

confidence: 99%

“…Early diagnosis of inhalational anthrax would be difficult and would require a high index of suspicion (3). For this reason, the use of nontraditional data sources, such as grocery and pharmacy data, school attendance records, uses of web sources, etc., could improve the chances of detection.…”

Section: Medical and Public Health Datamentioning

confidence: 99%

“…Death may occur in as little as 2-48 h (3). Unlike what we observed in the fall of 2001, when the country was on heightened alert and small numbers of people were exposed (i.e., only 11 cases spread geographically), diagnosis of large-scale inhalational anthrax exposure based on medical and public health facilities would more likely occur after a large number of patients seeking medical treatment in some geographical area with an acuteonset flu-like illness and case fatality rate of 80% or more, usually within 24-48 h. In addition, blood tests would provide only a preliminary diagnosis 6-24 h later and could possibly go unidentified if the lab had not been alerted to the possibility of anthrax, whereas rapid diagnostic tests are available only at national reference laboratories (3).…”

Section: Medical and Public Health Datamentioning

confidence: 99%

See 1 more Smart Citation

Early statistical detection of anthrax outbreaks by tracking over-the-counter medication sales

Goldenberg

Shmueli

Caruana

et al. 2002

140

The recent series of anthrax attacks has reinforced the importance of biosurveillance systems for the timely detection of epidemics. This paper describes a statistical framework for monitoring grocery data to detect a large-scale but localized bioterrorism attack. Our system illustrates the potential of data sources that may be more timely than traditional medical and public health data. The system includes several layers, each customized to grocery data and tuned to finding footprints of an epidemic. We also propose an evaluation methodology that is suitable in the absence of data on large-scale bioterrorist attacks and disease outbreaks.biosurveillance ͉ time series analysis ͉ grocery data W e describe a statistical system designed for biosurveillance that is part of a larger project investigating ways to use information technology to improve clinical preparedness for bioterrorism (1). Our goal is evaluating the possible use of non-public health data, and in particular grocery sales, for the early detection of a bioterrorism attack. The potential of these data for timely detection lies in the earlier manifestation of an attack in grocery and over-the-counter (OTC) medication sales, and in their high level of detail.We begin in the next section by providing background and a characterization of an outbreak of a bioagent, focusing on anthrax. Then we describe traditional data collected from medical and public health sources and their ability to detect attacks in a timely fashion, before turning to grocery data and the detection system that we developed. We also introduce a method for evaluating the detection system in the absence of a bioagent footprint in the data, and for tuning the system to the input data. We end with some observations on the usefulness of our approach. Historical and Current Biological OutbreaksVarious bioagents have been identified as possible weapons in biological warfare. Here, we focus on anthrax to illustrate how a detection system that tracks OTC medication sales can provide more timely signals than traditional systems that track medical and public health data. The statistical framework is general, however, and can be applied for the detection of other agents.