Isolated case of bioterrorism-related inhalational anthrax, New York City, 2001 - Research

Emerging Infectious Diseases, June, 2003 by Timothy H. Holtz, Joel Ackelsberg, Jacob L. Kool, Richard Rosselli, Anthony Marfin, Thomas Matte, Sara T. Beatrice, Michael B. Heller, Dan Hewett, Linda C. Moskin, Michel L. Bunning, Marcelle Layton

On October 31, 2001, in New York City, a 61-year-old female hospital employee who had acquired inhalational anthrax died after a 6-day illness. To determine sources of exposure and identify additional persons at risk, the New York City Department of Health, Centers for Disease Control and Prevention, and law enforcement authorities conducted an extensive investigation, which included interviewing contacts, examining personal effects, summarizing patient's use of mass transit, conducting active case finding and surveillance near her residence and at her workplace, and collecting samples from co-workers and the environment. We cultured all specimens for Bacillus anthracis. We found no additional cases of cutaneous or inhalational anthrax. The route of exposure remains unknown. All environmental samples were negative for B. anthracis. This first case of inhalational anthrax during the 2001 outbreak with no apparent direct link to contaminated mail emphasizes the need for close coordination between public health and law enforcement agencies during bioterrorism-related investigations.

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After the World Trade Center attack on September 11, 200 I, the possibility of bioterrorism in New York City (NYC) became a preeminent concern at the Department of Health (DOH). Active syndromic surveillance at emergency department for bioterrorism-related illnesses was initiated in 15 hospitals, and frequent broadcast alerts were sent by email and fax to all NYC emergency departments, commercial and hospital laboratories, infection-control programs, and selected providers (1).

After the announcement of the inhalational anthrax index case in Florida on October 4 and the cutaneous anthrax index case in NYC on October 12, DOH enhanced its active surveillance activities citywide (2). Detailed diagnostic and treatment protocols were provided through a broadcast alert system and the DOH website to the medical and laboratory community, including emergency departments, intensive-care units, infectious disease and infection-control specialists, dermatologists, and laboratories. A provider hotline was established for rapid referral and evaluation of suspect cases. Broadcast fax alerts also were sent to veterinarians to request reporting of suspect animal cases. In addition, the emergency department--based syndromic surveillance system was expanded to 29 hospitals to augment DOH's ability to detect a large, covert bioterrorist event. The medical examiner's office was asked to notify DOH of any suspicious deaths from unexplained sepsis or respiratory causes.

During October, four simultaneous investigations were conducted at news media outlets where cutaneous anthrax cases were detected among employees (M. Phillips, et al., unpub. data). All interviews were performed by teams of investigators from DOH, Centers for Disease Control and Prevention (CDC), and law enforcement on the basis of pre-established agreements between DOH and the New York field office of the Federal Bureau of Investigation (FBI), and its associated Joint Terrorism Task Force (a task force between the NYC Police Department and FBI). By the end of October 2001, seven laboratory-confirmed or suspected cutaneous anthrax cases had been reported in NYC. All case-patients were thought to have been exposed through direct contact with contaminated mail addressed to media outlets and postmarked on September 18 (3). The last known contaminated letters were postmarked on October 9 from Trenton, New Jersey, to Senators Thomas Daschle and Patrick Leahy in Washington, D.C.

Case Confirmation

On October 28, 2001, a local hospital reported a suspected case of inhalational anthrax to DOH. The case-patient was a 61-year-old female with a 3-day history of progressive weakness, chest heaviness, myalgia, cough, and shortness of breath. She was admitted to intensive care with respiratory failure, emergently intubated before being interviewed, and treated with multiple antibiotics and diuretics for a presumptive diagnosis of community-acquired pneumonia, congestive heart failure, or inhalational anthrax (4). On October 29, nonmotile, gram-positive rods in long chains were isolated from routine blood cultures, and her antibiotic therapy was adjusted to provide for enhanced coverage of inhalational anthrax. That evening, Bacillus anthracis was preliminarily identified from her blood culture isolate and from pleural, fluid, and bronchial washings by polymerase chain reaction (PCR) at the DOH Public Health Laboratory and CDC. The following day, pleural and blood isolates were confirmed as B. anthracis by gamma phage lysis and direct fluorescent antibody testing. The case-patient died on October 31. B. anthracis isolates were subtyped at CDC by multiple-locus variable-number tandem repeat analysis (MLVA) and sequencing of the pagA gene. All isolates were MLVA genotype 62 and pagA genotype I, the same genotype as all other isolates from the 2001 anthrax outbreak in Florida, New Jersey, Washington, D.C., and Connecticut (5).