Anthrax is an acute infectious disease caused by the spore-forming bacterium called Bacillus anthracis. The bacterium is commonly found in the soil and forms spores (like seeds) that can remain dormant for many years. Although anthrax can infect humans, it occurs most commonly in plant-eating animals. Human anthrax infections are rare in the United States and have normally resulted from occupational exposure to infected animals or contaminated animal products, such as wool, hides, or hair. Infection can occur in three forms, two of which are relevant to this testimony. They are (1) cutaneous, which usually occurs through a cut or abrasion and (2) inhalation, which results from breathing aerosolized anthrax spores into the lungs.Aerosolization occurs when anthrax spores become airborne, thus enabling a person to inhale the spores into the lungs. After the spores enter the body, they can germinate into bacteria, which then multiply and secrete toxins that can produce local swelling and tissue death. The symptoms are different for each form of infection and are thought to appear within about 7 days of exposure, although individuals have contracted inhalation anthrax as long as 43 days after exposure. Depending on the extent of exposure and its form, a person can be exposed to anthrax without developing an infection. Before the 2001 incidents, the fatality rate for inhalation anthrax was approximately 75 percent, even with appropriate antimicrobial medications. People coming in contact with anthrax in its natural environment have generally not been at risk for inhalation anthrax, and before 2001, no cases of inhalation anthrax had been reported in the United States since 1976, although 224 cases of cutaneous anthrax were diagnosed between 1944 and 1994.Fatalities are rare for cutaneous anthrax. Because so few instances of inhalation anthrax have occurred, scientific understanding about the number of spores needed to cause the disease is still evolving. Before the 2001 incidents, it was estimated that a person would need to inhale thousands of spores to develop inhalation anthrax. However, based on the cases that occurred during the fall of 2001, experts now believe that the number of spores needed to cause inhalation anthrax could be very small, depending on a person’s health status and the aerosolization capacity of the anthrax spores. In total, the contaminated letters caused 22 illnesses and resulted in 5 deaths from inhalation anthrax. Numerous postal facilities were also contaminated. The first two cases of disease involved media employees in Florida. The employees—one of whom died—contracted inhalation anthrax and were thought to have contracted the disease through proximity to opened letters containing anthrax spores. Media employees also developed anthrax in New York—the second location known to be affected. The initial cases in New York were all cutaneous and were also thought to have been associated with opened envelopes containing anthrax spores. The initial cases at the next site—New Jersey—involved postal employees with cutaneous anthrax. The postal employees were believed to have contracted the disease through handling the mail—as opposed to opening or being exposed to opened letters containing anthrax spores. Unlike the incidents at other locations, which began when cases of anthrax were detected, the incident at the Hart Building—the fourth location—began with the opening of a letter containing anthrax spores and the resulting exposure to the contamination. The discovery of inhalation anthrax in the first postal worker from Brentwood revealed that even individuals who had been exposed only to taped and sealed envelopes containing anthrax could contract the inhalation form of the disease. Subsequent inhalation cases in Washington, D.C.; New Jersey; New York; and Connecticut—the sixth location affected—underscored that finding and also demonstrated that exposure and illness could result from cross contamination of mail. (See app. I for a time line of selected events related to the anthrax incident in the fall of 2001.) On or about October 9, 2001, at least two letters containing anthrax spores entered the U.S. mail stream—one was addressed to Senator Thomas Daschle, the other to Senator Patrick Leahy. The letters were mailed in Trenton, New Jersey, and forwarded to the Brentwood facility in Washington, D.C., where they were processed on high-speed mail sorting machines and further processed in the facility’s government mail section before delivery. On October 15, a staff member in Senator Daschle’s office opened the contaminated envelope. The envelope contained a powdery substance, which the accompanying letter identified as anthrax, that was released in a burst of dust when the envelope was opened. The U.S. Capitol Police were notified, and the substance was quickly tested and confirmed to be anthrax. Brentwood managers analyzed the path of the letter through the facility. Although the machine that processed the letter was reportedly shut off—at least for a period of time—the facility itself was not closed or evacuated at that time. Within days, a Brentwood employee was suspected of having contracted inhalation anthrax. The Postal Service closed the facility on October 21, 2001, after CDC confirmed that the employee had the disease. Thereafter, two other Brentwood employees, Mr. Curseen, Jr., and Mr. Morris, Jr., died. Both were subsequently found to have died of inhalation anthrax. The Brentwood facility is a large 2-story facility that operated 24 hours a day, 7 days a week. About 2,500 employees worked at Brentwood, processing mail on one of three shifts. Brentwood processed all the mail delivered to addresses on Capitol Hill, including the Hart Building. Brentwood was the second processing and distribution center closed for an extended period because of anthrax contamination. The Postal Service reported that it plans to reopen the facility in phases; by late November administrative personnel will begin working in the facility and limited mail processing operations will begin shortly after that. Brentwood is expected to be fully operational by spring 2004. The other facility—the Trenton Processing and Distribution Center—located in Hamilton, New Jersey, was closed 3 days before Brentwood on October 18, 2001, after CDC confirmed that a New Jersey postal employee had cutaneous anthrax. It is in the process of being decontaminated. The Postal Service’s decision to wait for CDC’s confirmation of a case of inhalation anthrax before closing Brentwood and referring the facilities’ employees for medical treatment was consistent with the public health advice the Postal Service received and the health risk information available at the time. However, the Postal Service’s decision contrasted with the more immediate decision to close the Hart Building after anthrax contamination occurred. As a result, postal employees questioned whether the Postal Service’s decision adequately protected their health. The Postal Service’s decision to wait for CDC’s confirmation of a case of inhalation anthrax before closing Brentwood and referring its employees for medical treatment was consistent with the advice provided by CDC and the D.C. Department of Health, as well as the available health risk information. CDC called for such confirmation before closing a facility or recommending medical treatment because, at the time, public health authorities believed postal employees were unlikely to contract inhalation anthrax from exposure to contaminated mail. Postal officials reported that they consulted CDC and the D.C. Department of Health about the possible health risks to Brentwood employees after learning that Senator Daschle’s letter—opened on October 15, 2001—contained anthrax. Even though the letter would have passed through Brentwood, the public health authorities said that they did not consider the facility’s employees at risk, given the results of ongoing investigations of anthrax incidents in Florida and New York and the scientific understanding at that time. Specifically, as discussed, no postal employees were known to have developed symptoms of anthrax after contaminated letters had passed through the postal system on the way to destinations in Florida and New York, and anthrax spores were not considered likely to leak out, or escape from, a taped and well-sealed envelope in sufficient quantities to cause inhalation anthrax. Accordingly, the Postal Service reported that it kept the Brentwood facility open in order to keep the mail moving. This goal was important to managers whom we interviewed, who cited the psychological importance of keeping the mail flowing in the aftermath of the September 11 terrorist attacks. On October 18, 2001, CDC confirmed that a postal employee in New Jersey had cutaneous anthrax. On that day, the Postal Service, in consultation with the New Jersey Department of Health and Senior Services, closed the Trenton Processing and Distribution Center. According to New Jersey public health officials, the facility was closed to facilitate environmental testing of the Trenton facility. While the contaminated letters to Senator Daschle and Senator Leahy were both processed through the Trenton and Brentwood facilities, it is not clear why the Postal Service did not take the same precautionary measures at Brentwood. We are pursuing this issue as part of our ongoing work. Although the Postal Service followed CDC’s advice and kept Brentwood open until CDC confirmed a case of inhalation anthrax, the Postal Service took interim steps to protect its employees. First, the Postal Service arranged for a series of environmental tests at the Brentwood facility, even though it reported that CDC had advised the Postal Service that it did not believe such testing was needed at that time. The results of the first test— taken and available on October 18, 2001—were from a quick test conducted by a local hazardous materials response team. The results were negative. Three days later, on October 21, 2001, CDC confirmed that a Brentwood employee had inhalation anthrax, and the Postal Service closed the facility and referred its employees for medical treatment. The positive results of more extensive environmental testing—also conducted on October 18, 2001—were not available until October 22—after the facility had already closed. In addition, Postal Service managers said they asked the D.C. Department of Health three times before October 21 for nasal swabs and antibiotics for Brentwood employees; however, the health department said the swabs and antibiotics were unnecessary.