After inhalational anthrax was diagnosed in a Connecticut woman on November 20, 2001, postexposure prophylaxis was recommended for postal workers at the regional mail facility serving the patient’s area. Although environmental testing at the facility yielded negative results, subsequent testing confirmed the presence of Bacillus anthracis. We distributed questionnaires to 100 randomly selected postal workers within 20 days of initial prophylaxis. Ninety-four workers obtained antibiotics, 68 of whom started postexposure prophylaxis and 21 discontinued. Postal workers who stopped or never started taking prophylaxis cited as reasons disbelief regarding anthrax exposure, problems with adverse events, and initial reports of negative cultures. Postal workers with adverse events reported predominant symptoms of gastrointestinal distress and headache. The influence of these concerns on adherence suggests that communication about risks of acquiring anthrax, education about adverse events, and careful management of adverse events are essential elements in increasing adherence.
Anthrax; Bacillus anthracis; prophylaxis; adverse effects; ciprofloxacin; doxycycline; patient noncompliance; Connecticut
In October 2001, two envelopes containing Bacillus anthracis spores were processed at the Washington, D.C., Processing and Distribution Center of the U.S. Postal Service; inhalational anthrax developed in four workers at this facility. More than 2,000 workers were advised to complete 60 days of postexposure prophylaxis to prevent inhalational anthrax. Interventions to promote adherence were carried out to support workers, and qualitative information was collected to evaluate our interventions. A quantitative survey was administered to a convenience sample of workers to assess factors influencing adherence. No anthrax infections developed in any workers involved in the interventions or interviews. Of 245 workers, 98 (40%) reported full adherence to prophylaxis, and 45 (18%) had completely discontinued it. Experiencing adverse effects to prophylaxis, anxiety, and being <45 years old were risk factors for discontinuing prophylaxis. Interventions, especially frequent visits by public health staff, proved effective in supporting adherence.
adherence; Bacillus anthracis; bioterrorism; antimicrobial prophylaxis; compliance
Protocols for mass antibiotic prophylaxis against anthrax were under development in New York City beginning in early 1999. This groundwork allowed the city’s Department of Health to rapidly respond in 2001 to six situations in which cases were identified or anthrax spores were found. The key aspects of planning and lessons learned from each of these mass prophylaxis operations are reviewed. Antibiotic distribution was facilitated by limiting medical histories to issues relevant to prescribing prophylactic antibiotic therapy, formatting medical records to facilitate rapid decision making, and separating each component activity into discrete work stations. Successful implementation of mass prophylaxis operations was characterized by clarity of mission and eligibility criteria, well-defined lines of authority and responsibilities, effective communication, collaboration among city agencies (including law enforcement), and coordination of staffing and supplies. This model can be adapted for future planning needs including possible attacks with other bioterrorism agents, such as smallpox.
anthrax prophylaxis; bioterrorism; public health response; policy review
Inappropriate use of antibiotics by individuals worried about biological agent exposures during bioterrorism events is an important public health concern. However, little is documented about the extent to which individuals with self-identified risk of anthrax exposure approached physicians for antimicrobial prophylaxis during the 2001 bioterrorism attacks in the United States.
We conducted a telephone survey of randomly selected members of the Pennsylvania Chapter of the American College of Emergency Physicians to assess patients' request for and emergency physicians' prescription of antimicrobial agents during the 2001 anthrax attacks.
Ninety-seven physicians completed the survey. Sixty-four (66%) respondents had received requests from patients for anthrax prophylaxis; 16 (25%) of these physicians prescribed antibiotics to a total of 23 patients. Ten physicians prescribed ciprofloxacin while 8 physicians prescribed doxycycline.
During the 2001 bioterrorist attacks, the majority of the emergency physicians we surveyed encountered patients who requested anthrax prophylaxis. Public fears may lead to a high demand for antibiotic prophylaxis during bioterrorism events. Elucidation of the relationship between public health response to outbreaks and outcomes would yield insights to ease burden on frontline clinicians and guide strategies to control inappropriate antibiotic allocation during bioterrorist events.
We used unpublished reports, published manuscripts, and communication with investigators to identify and summarize 49 anthrax-related epidemiologic field investigations conducted by the Centers for Disease Control and Prevention from 1950 to August 2001. Of 41 investigations in which Bacillus anthracis caused human or animal disease, 24 were in agricultural settings, 11 in textile mills, and 6 in other settings. Among the other investigations, two focused on building decontamination, one was a response to bioterrorism threats, and five involved other causes. Knowledge gained in these investigations helped guide the public health response to the October 2001 intentional release of B. anthracis, especially by addressing the management of anthrax threats, prevention of occupational anthrax, use of antibiotic prophylaxis in exposed persons, use of vaccination, spread of B. anthracis spores in aerosols, clinical diagnostic and laboratory confirmation methods, techniques for environmental sampling of exposed surfaces, and methods for decontaminating buildings.
anthrax; Bacillus anthracis; bacterial infections; disease outbreaks; public health; bioterrorism; Centers for Disease Control and Prevention (U.S.); historical article (publication type); zoonoses
A mathematical model suggests that a HEPA/vaccine approach is viable for most buildings after a large-scale anthrax attack.
We developed a mathematical model to compare 2 indoor remediation strategies in the aftermath of an outdoor release of 1.5 kg of anthrax spores in lower Manhattan. The 2 strategies are the fumigation approach used after the 2001 postal anthrax attack and a HEPA/vaccine plan, which relies on HEPA vacuuming, HEPA air cleaners, and vaccination of reoccupants. The HEPA/vaccine approach leads to few anthrax cases among reoccupants if applied to all but the most heavily contaminated buildings, and recovery is much faster than under the decades-long fumigation plan. Only modest environmental sampling is needed. A surge capacity of 10,000 to 20,000 Hazmat workers is required to perform remediation within 6 to 12 months and to avoid permanent mass relocation. Because of the possibility of a campaign of terrorist attacks, serious consideration should be given to allowing or encouraging voluntary self-service cleaning of lightly contaminated rooms by age-appropriate, vaccinated, partially protected (through masks or hoods) reoccupants or owners.
research; HEPA filter; anthrax; mathematical model; bioterrorism; remediation; vaccine
We collected data during postexposure antimicrobial prophylaxis campaigns and from a prophylaxis program evaluation 60 days after start of antimicrobial prophylaxis involving persons from six U.S. sites where Bacillus anthracis exposures occurred. Adverse events associated with antimicrobial prophylaxis to prevent anthrax were commonly reported, but hospitalizations and serious adverse events as defined by Food and Drug Administration criteria were rare. Overall adherence during 60 days of antimicrobial prophylaxis was poor (44%), ranging from 21% of persons exposed in the Morgan postal facility in New York City to 64% of persons exposed at the Brentwood postal facility in Washington, D.C. Adherence was highest among participants in an investigational new drug protocol to receive additional antibiotics with or without anthrax vaccine—a likely surrogate for anthrax risk perception. Adherence of <60 days was not consistently associated with adverse events.
Anthrax; Bacillus anthracis; antimicrobial prophylaxis; adverse events; adherence
The October 2001 anthrax attacks heralded a new era of bioterrorism threat in the U.S. At the time, little systematic data on mental health effects were available to guide authorities' response. For this study, which was conducted 7 months after the anthrax attacks, structured diagnostic interviews were conducted with 137 Capitol Hill staff workers, including 56 who had been directly exposed to areas independently determined to have been contaminated. Postdisaster psychopathology was associated with exposure; of those with positive nasal swab tests, PTSD was diagnosed in 27% and any post-anthrax psychiatric disorder in 55%. Fewer than half of those who were prescribed antibiotics completed the entire course, and only one-fourth had flawless antibiotic adherence. Thirty percent of those not exposed believed they had been exposed; 18% of all study participants had symptoms they suspected were symptoms of anthrax infection, and most of them sought medical care. Extrapolation of raw numbers to large future disasters from proportions with incorrect belief in exposure in this limited study indicates a potential for important public health consequences, to the degree that people alter their healthcare behavior based on incorrect exposure beliefs. Incorrect belief in exposure was associated with being very upset, losing trust in health authorities, having concerns about mortality, taking antibiotics, and being male. Those who incorrectly believe they were exposed may warrant concern and potential interventions as well as those exposed. Treatment adherence and maintenance of trust for public health authorities may be areas of special concern, warranting further study to inform authorities in future disasters involving biological, chemical, and radiological agents.
The CDC recommend 60 days of oral antibiotics combined with a three-dose series of the anthrax vaccine for prophylaxis after potential exposure to aerosolized Bacillus anthracis spores. The anthrax vaccine is currently not licensed for anthrax postexposure prophylaxis and has to be made available under an Investigational New Drug protocol. Postexposure prophylaxis based on antibiotics can be problematic in cases where the use of antibiotics is contraindicated. Furthermore, there is a concern that an exposure could involve antibiotic-resistant strains of B. anthracis. Availability of alternate treatment modalities that are effective in prophylaxis of inhalation anthrax is therefore highly desirable. A major research focus toward this end has been on passive immunization using polyclonal and monoclonal antibodies against B. anthracis toxin components. Since 2001, significant progress has been made in isolation and commercial development of monoclonal and polyclonal antibodies that function as potent neutralizers of anthrax lethal toxin in both a prophylactic and therapeutic setting. Several new products have completed Phase I clinical trials and are slated for addition to the National Strategic Stockpile. These rapid advances were possible because of major funding made available by the US government through programs such as Bioshield and the Biomedical Advanced Research and Development Authority. Continued government funding is critical to support the development of a robust biodefense industry.
antibiotic treatment; biodefense funding; inhalation anthrax; lethal factor; medical countermeasures; prophylactic antibodies; protective antigen; vaccination
In 1991, most physicians in Minnesota and Wisconsin managed patients concerns about anthrax without dispensing prophylactic antimicrobial agents.
Media reports suggested increased public demand for anthrax prophylaxis after the intentional anthrax cases in 2001, but the magnitude of anthrax-related prescribing in unaffected regions was not assessed. We surveyed a random sample of 400 primary care clinicians in Minnesota and Wisconsin to assess requests for and provision of anthrax-related antimicrobial agents. The survey was returned by 239 (60%) of clinicians, including 210 in outpatient practice. Fifty-eight (28%) of those in outpatient practice received requests for anthrax-related antimicrobial agents, and 9 (4%) dispensed them. Outpatient fluoroquinolone use in both states was also analyzed with regression models to compare predicted and actual use in October and November 2001. Fluoroquinolone use as a proportion of total antimicrobial use was not elevated, and anthrax concerns accounted for an estimated 0.3% of all fluoroquinolone prescriptions. Most physicians in Minnesota and Wisconsin managed anthrax-related requests without dispensing antimicrobial agents.
research, anthrax, fluoroquinolone, prophylaxis; drug resistance; bioterrorism
In 2001, the intentional release of anthrax spores in the eastern United States increased concern about exposure to anthrax nationwide, and residents of Idaho sought assistance. Response from state and local agencies was required, increasing the strain on epidemiologists, laboratorians, and communications personnel. In late 2001, Idaho’s public health communications system handled 133 calls about suspicious powders. For each call, a multiagency bridge call was established, and participants (public health officials, epidemiologists, police, Federal Bureau of Investigation personnel, hazardous materials officials, and others) determined which samples would be tested by the state public health laboratory. A triage system for calls helped relieve the burden on public safety and health systems.
anthrax; bioterrorism; Idaho
The biological attacks with powders containing Bacillus anthracis sent through the mail during September and October 2001 led to unprecedented public health and law enforcement investigations, which involved thousands of investigators from federal, state, and local agencies. Following recognition of the first cases of anthrax in Florida in early October 2001, investigators from Centers for Disease Control and Prevention (CDC) and the Federal Bureau of Investigation (FBI) were mobilized to assist investigators from state and local public health and law enforcement agencies. Although public health and criminal investigations have been conducted in concert in the past, the response to the anthrax attacks required close collaboration because of the immediate and ongoing threat to public safety. We describe the collaborations between CDC and FBI during the investigation of the 2001 anthrax attacks and highlight the challenges and successes of public health and law enforcement collaborations in general.
police power; anthrax; quarantine; bioterrorism response; Bacillus anthracis; law; criminal investigation; Federal Bureau of Investigation
The biological attack conducted through the U.S. postal system in 2001 broadened the threat posed by anthrax from one pertinent mainly to soldiers on the battlefield to one understood to exist throughout our society. The expansion of the threatened population placed greater emphasis on the reexamination of how we vaccinate against Bacillus anthracis. The currently-licensed Anthrax Vaccine, Adsorbed (AVA) and Anthrax Vaccine, Precipitated (AVP) are capable of generating a protective immune response but are hampered by shortcomings that make their widespread use undesirable or infeasible. Efforts to gain U.S. Food and Drug Administration (FDA) approval for licensure of a second generation recombinant protective antigen (rPA)-based anthrax vaccine are ongoing. However, this vaccine's reliance on the generation of a humoral immune response against a single virulence factor has led a number of scientists to conclude that the vaccine is likely not the final solution to optimal anthrax vaccine design. Other vaccine approaches, which seek a more comprehensive immune response targeted at multiple components of the B. anthracis organism, are under active investigation. This review seeks to summarize work that has been done to build on the current PA-based vaccine methodology and to evaluate the search for future anthrax prophylaxis strategies.
Bacillus anthracis; anthrax; vaccine
Effective health protection requires systematised responses with clear accountabilities. In England, Primary Care Trusts and the Health Protection Agency both have statutory responsibilities for health protection. A Memorandum of Understanding identifies responsibilities of both parties, but there is a potential lack of clarity about responsibility for specific health protection functions. We aimed to investigate professionals' perceptions of responsibility for different health protection functions, to inform future guidance for, and organisation of, health protection in England.
We sent a postal questionnaire to all health protection professionals in England from the following groups: (a) Directors of Public Health in Primary Care Trusts; (b) Directors of Health Protection Units within the Health Protection Agency; (c) Directors of Public Health in Strategic Health Authorities and; (d) Regional Directors of the Health Protection Agency
The response rate exceeded 70%. Variations in perceptions of who should be, and who is, delivering health protection functions were observed within, and between, the professional groups (a)-(d). Concordance in views of which organisation should, and which does deliver was high (≥90%) for 6 of 18 health protection functions, but much lower (≤80%) for 6 other functions, including managing the implications of a case of meningitis out of hours, of landfill environmental contamination, vaccination in response to mumps outbreaks, nursing home infection control, monitoring sexually transmitted infections and immunisation training for primary care staff. The proportion of respondents reporting that they felt confident most or all of the time in the safe delivery of a health protection function was strongly correlated with the concordance (r = 0.65, P = 0.0038).
Whilst we studied professionals' perceptions, rather than actual responses to incidents, our study suggests that there are important areas of health protection where consistent understanding of responsibility for delivery is lacking. There are opportunities to clarify the responsibility for health protection in England, perhaps learning from the approaches used for those health protection functions where we found consistent perceptions of accountability.
In a public health emergency, it becomes necessary for public health agencies to provide timely, accurate and useful information to the community. During the anthrax attacks, the Public Health Practice Program Office in the Centers for Disease Control and Prevention implemented a knowledge management (KM) system to respond to an increased number of inquiries from public health officials, first responders, and health care professionals as well as the general public. While it is possible to successfully implement a knowledge management system quickly in a crisis situation, additional challenges to sustainability may result from shortchanging the normal decision-making channels.
The recent public health risks arising from bioterrorist threats and outbreaks of infectious diseases like SARS (Severe Acute Respiratory Syndrome) highlight the challenges of effectively communicating accurate health information to an alarmed public.
To evaluate use of the Internet in accessing information related to the anthrax scare in the United States in late 2001, and to strategize about the most effective use of this technology as a communication vehicle during times of public health crises.
A paper-based survey to assess how individuals obtained health information relating to bioterrorism and anthrax during late 2001.We surveyed 500 randomly selected patients from two ambulatory primary care clinics affiliated with the Brigham and Women's Hospital in Boston, Massachusetts.
The response rate was 42%. While traditional media provided the primary source of information on anthrax and bioterrorism, 21% (95% CI, 15% - 27%) of respondents reported searching the Internet for this information during late 2001. Respondents reported trusting information from physicians the most, and information from health websites slightly more than information from any traditional media source. Over half of those searching the Internet reported changing their behavior as a result of information found online.
Many people already look to the Internet for information during a public health crisis, and information found online can positively influence behavioral responses to such crises. However, the potential of the Internet to convey accurate health information and advice has not yet been realized. In order to enhance the effectiveness of public-health communication, physician practices could use this technology to pro-actively e-mail their patients validated information. Still, unless Internet access becomes more broadly available, its benefits will not accrue to disadvantaged populations.
bioterrorism; public health; communication; electronic mail; inequality; behavior
In the wake of the September 11, 2001, attacks and the subsequent anthrax scare, there is growing concern about the United States' vulnerability to terrorist use of Weapons of Mass Destruction (WMD). As part of ongoing preparation for this terrible reality, many jurisdictions have been conducting simulated terrorist incidents to provide training for the public safety community, hospitals, and public health departments. As an example of this national effort to improve domestic preparedness for such events, a large scale, multi-jurisdictional chemical weapons drill was conducted in Cincinnati, Ohio, on May 20, 2000. This drill depicted the components of the early warning system for hospitals and public health departments, the prehospital medical response to terrorism. Over the course of the exercise, emergency medical services personnel decontaminated, triaged, treated, and transported eighty-five patients. Several important lessons were learned that day that have widespread applicability to health care delivery systems nationwide, especially in the areas of decontamination, triage, on-scene medical care, and victim transportation. As this training exercise helped Cincinnati to prepare for dealing with future large scale WMD incidents, such drills are invaluable preparation for all communities in a world increasingly at risk from terrorist attacks.
In October 2001, four cases of inhalational anthrax occurred in workers in a Washington, D.C., mail facility that processed envelopes containing Bacillus anthracis spores. We reviewed the envelopes’ paths and obtained exposure histories and nasal swab cultures from postal workers. Environmental sampling was performed. A sample of employees was assessed for antibody concentrations to B. anthracis protective antigen. Case-patients worked on nonoverlapping shifts throughout the facility. Environmental sampling showed diffuse contamination of the facility, suggesting multiple aerosolization events. Potential workplace exposures were similar for the case-patients and the sample of workers. All nasal swab cultures and serum antibody tests were negative. Available tools could not identify subgroups of employees at higher risk for exposure or disease. Prophylaxis was necessary for all employees. To protect postal workers against bioterrorism, measures to reduce the risk of occupational exposure are necessary.
bioterrorism; Bacillus anthracis; postal facility; inhalational anthrax
On October 12, 2001, two envelopes containing Bacillus anthracis spores passed through a sorting machine in a postal facility in Washington, D.C. When anthrax infection was identified in postal workers 9 days later, the facility was closed. To determine if exposure to airborne B. anthracis spores continued to occur, we performed air sampling around the contaminated sorter. One CFU of B. anthracis was isolated from 990 L of air sampled before the machine was activated. Six CFUs were isolated during machine activation and processing of clean dummy mail. These data indicate that an employee working near this machine might inhale approximately 30 B. anthracis-containing particles during an 8-h work shift. What risk this may have represented to postal workers is not known, but the risk is approximately 20-fold less than estimates of sub-5 micron B. anthracis-containing particles routinely inhaled by asymptomatic, unvaccinated workers in a goat-hair mill.
Bacillus anthracis; anthrax; risk assessment; occupational exposure
Health emergency planning for preparedness and response against acts of terrorism, including the malfeasant threat or actual release of biological agents designed to harm others, has assumed a higher level of concern for most western nations, including Canada, following the explosive attacks in the United States on September 11, 2001. These terrorist attacks were followed by an outbreak of anthrax infections. The Bacillus anthracis spores in these attacks were dispersed by using regular postal services in the United States. In addition to the unsettling sense of social vulnerability that resulted from these attacks, a greater appreciation that the integration of public health, emergency health and social services with security activities was required to fully address the need to protect the health and other interests of the citizens. Collaborative work among regional, provincial, territorial, federal and international authorities within these domains is emerging as an effective response to the risk management of bioterrorism. The following is a brief description of the health framework for preparedness and response, and the biological agents of major concern in terrorism.
Bioterrorism; Health emergency
During times of public health emergencies, effective communication between the emergency response agencies and the affected public is important to ensure that people protect themselves from injury or disease. In order to investigate compliance with public health advice during natural disasters, we examined consumer behaviour during two water notices that were issued as a result of serious flooding. During the summer of 2007, 140,000 homes in Gloucestershire, United Kingdom, that are supplied water from Mythe treatment works, lost their drinking water for up to 17 days. Consumers were issued a 'Do Not Drink' notice when the water was restored, which was subsequently replaced with a 'Boil Water' notice. The rare occurrence of two water notices provided a unique opportunity to compare compliance with public health advice. Information source use and other factors that may affect consumer perception and behaviour were also explored.
A postal questionnaire was sent to 1,000 randomly selected households. Chi-square, ANOVA, MANOVA and generalised estimating equation (with and without prior factor analysis) were used for quantitative analysis.
In terms of information sources, we found high use of and clear preference for the local radio throughout the incident, but family/friends/neighbours also proved crucial at the onset. Local newspapers and the water company were associated with clarity of advice and feeling informed, respectively. Older consumers and those in paid employment were particularly unlikely to read the official information leaflets. We also found a high degree of confusion regarding which notice was in place at which time, with correct recall varying between 23.2%-26.7%, and a great number of consumers believed two notices were in place simultaneously. In terms of behaviour, overall non-compliance levels were significantly higher for the 'Do Not Drink' notice (62.9%) compared to the 'Boil Water' notice (48.3%); consumers in paid employment were not likely to comply with advice. Non-compliance with the general advice to boil bowser water was noticeably lower (27.3%).
Higher non-compliance during the 'Do Not Drink' notice was traced to the public's limited knowledge of water notices and their folk beliefs about the protection offered from boiling water. We suggest that future information dissemination plans reduce reliance on official leaflets and maximise the potential of local media and personal networks. Current public health education programmes are recommended to attend to insufficient and incorrect public knowledge about precautionary actions.
Vaccines have virtually eliminated many diseases, but public concerns about their safety could undermine future public health initiatives.
To determine Canadians' attitudes and knowledge about vaccines, particularly in view of increasing public concern about bioterrorism and the possible need for emergency immunizations after weaponized anthrax incidents and the events of September 11, 2001.
A 20-question survey based on well-researched dimensions of vaccine responsiveness was telephone-administered to a random sample of N = 1330 adult Canadians in January, 2002.
1057 (79.5%) completed the survey. Respondents perceived vaccines to be highly effective and demonstrated considerable support for further vaccine research. However, results also indicate a lack of knowledge about vaccines and uncertainty regarding the safety.
Support for vaccines is broad but shallow. While Canadians hold generally positive attitudes about vaccines, support could be undermined by widely publicized adverse events. Better public education is required to maintain support for future public health initiatives.
preventive vaccines; attitudes; knowledge; nationwide Canadian survey
Infectious disease emergency preparedness planners should consider the special medical issues of pregnant women.
Emerging infectious disease outbreaks and bioterrorism attacks warrant urgent public health and medical responses. Response plans for these events may include use of medications and vaccines for which the effects on pregnant women and fetuses are unknown. Healthcare providers must be able to discuss the benefits and risks of these interventions with their pregnant patients. Recent experiences with outbreaks of severe acute respiratory syndrome, monkeypox, and anthrax, as well as response planning for bioterrorism and pandemic influenza, illustrate the challenges of making recommendations about treatment and prophylaxis for pregnant women. Understanding the physiology of pregnancy, the factors that influence the teratogenic potential of medications and vaccines, and the infection control measures that may stop an outbreak will aid planners in making recommendations for care of pregnant women during large-scale infectious disease emergencies.
Pregnancy; bioterrorism; communicable diseases; vaccines; synopsis
Public health ethics is neither taught widely in medical schools or schools of public health in the US or around the world. It is not surprising that health care professionals are particularly challenged when faced with ethical questions which extend beyond safeguarding the interests of their individual patients to matters that affect overall public good. The perceived threat of terror after September 11 2007, the anthrax attacks and the Katrina debacle are recent circumstances which may result in coercion. These have piqued the interest of medical professionals and the general public on public health ethics. The Ethics of Coercion in Mass Casualty Medicine written by Griffin Trotter MD, PhD attempts to fill a timely void in this area by examining the ethics of coercion in times of public health disasters.
At least four Bacillus anthracis–containing envelopes destined for New York City and Washington, D.C., were processed at the Trenton Processing and Distribution Center (PDC) on September 18 and October 9, 2001. When cutaneous anthrax was confirmed in a Trenton postal worker, the PDC was closed. Four cutaneous and two inhalational anthrax cases were identified. Five patients were hospitalized; none died. Four were PDC employees; the others handled or received mail processed there. Onset dates occurred in two clusters following envelope processing at the PDC. The attack rate among the 170 employees present when the B. anthracis–containing letters were sorted on October 9 was 1.2%. Of 137 PDC environmental samples, 57 (42%) were positive. Five (10%) of 50 local post offices each yielded one positive sample. Cutaneous or inhalational anthrax developed in four postal employees at a facility where B. anthracis–containing letters were processed. Cross-contaminated mail or equipment was the likely source of infection in two other case-patients with cutaneous anthrax.
Bacillus anthracis; anthrax; bioterrorism