SARS is a respiratory illness that has recently been reported principally in Asia, Europe, and North America. The World Health Organization reported on May 5, 2003, that there were an estimated 6,583 probable cases reported in 27 countries, including 61 cases in the United States. There have been 461 deaths worldwide, none of which have been in the United States. Of the 56 probable cases in the United States reported through April 30, 2003, 37 (66 percent) were hospitalized, and 2 (4 percent) required mechanical ventilation. Symptoms of the disease, which may be caused by a previously unrecognized coronavirus, can include a fever, chills, headache, other body aches, or a dry cough. A Canadian official recently reported that more than 60 percent of probable SARS cases in Canada, where the bulk of North American cases have occurred, resulted from transmission to health care workers and patients. Canada’s experience with managing the SARS outbreak has shown that measures used to prevent and control emerging infectious diseases appear to have been useful in controlling this outbreak. One of the measures that it has undertaken to control the outbreak is isolating probable cases in hospitals, including closing two hospitals to new admissions. Other measures include isolating people, either in their homes or in a hospital, who have had close contact with a SARS patient and providing educational materials regarding SARS to people who have traveled to locations of concern. In order to be adequately prepared for a major public health threat such as SARS in the United States, state and local public health agencies need to have several basic capabilities, whether they possess them directly or have access to them through regional agreements. Public health departments need to have disease surveillance systems and epidemiologists to detect clusters of suspicious symptoms or diseases in order to facilitate early detection of disease and treatment of victims. Laboratories need to have adequate capacity and necessary staff to test clinical and environmental samples in order to identify an agent promptly so that proper treatment can be started and infectious diseases prevented from spreading. All organizations involved in the response must be able to communicate easily with one another as events unfold and critical information is acquired, especially in a large-scale infectious disease outbreak. In addition, plans that describe how state and local officials would manage and coordinate an emergency response need to be in place and to have been tested in an exercise, both at the state and local levels and at the regional level. Local health care organizations, including hospitals, are generally responsible for the initial response to a public health emergency. In the event of a large-scale infectious disease outbreak, hospitals and their emergency departments would be on the front line, and their personnel would take on the role of first responders. Because hospital emergency departments are open 24 hours a day, 7 days a week, exposed individuals would be likely to seek treatment from the medical staff on duty. Staff would need to be able to recognize and report any illness patterns or diagnostic clues that might indicate an unusual infectious disease outbreak to their state or local health department. Hospitals would need to have the capacity and staff necessary to treat severely ill patients and limit the spread of infectious disease. In addition, hospitals would need adequate stores of equipment and supplies, including medications, personal protective equipment, quarantine and isolation facilities, and air handling and filtration equipment. The federal government also has a role in preparedness for and response to major public health threats. It becomes involved in investigating the cause of the disease, as it is doing with SARS. In addition, the federal government provides funding and resources to state and local entities to support preparedness and response efforts. CDC’s Public Health Preparedness and Response for Bioterrorism program provided funding through cooperative agreements in fiscal year 2002 totaling $918 million to states and municipalities to improve bioterrorism preparedness and response, as well as other public health emergency preparedness activities. HRSA’s Bioterrorism Hospital Preparedness Program provided funding through cooperative agreements in fiscal year 2002 of approximately $125 million to states and municipalities to enhance the capacity of hospitals and associated health care entities to respond to bioterrorist attacks. In March 2003, HHS announced that the CDC and HRSA programs would provide funding of approximately $870 million and $498 million, respectively, for fiscal year 2003. Among the other public health emergency response resources that the federal government provides is the Strategic National Stockpile, which contains pharmaceuticals, antidotes, and medical supplies that can be delivered anywhere in the United States within 12 hours of the decision to deploy. Just as was true with the identification of the coronavirus as the likely causative agent in SARS, deciding which influenza viral strains are dominant depends on data collected from domestic and international surveillance systems that identify prevalent strains and characterize their effect on human health. Antiviral drugs and vaccines against influenza are expected to be in short supply if a pandemic occurs. Antiviral drugs, which can be used against all forms of viral diseases, have been as effective as vaccines in preventing illness from influenza and have the advantage of being available now. HHS assumes shortages of antiviral drugs and vaccines will occur in a pandemic because demand is expected to exceed current rates of production. For example, increasing production capacity of antiviral drugs can take at least 6 to 9 months, according to manufacturers. In the cities we visited, state and local officials reported varying levels of public health preparedness to respond to outbreaks of diseases such as SARS. They recognized gaps in preparedness elements such as communication and were beginning to address them. Gaps also remained in other preparedness elements that have been more difficult to address, including the disease surveillance and laboratory systems and the response capacity of the workforce. In addition, we found that the level of preparedness varied across the cities. Jurisdictions that had multiple prior experiences with public health emergencies were generally more prepared than those with little or no such experience prior to our site visits. We found that planning for regional coordination was lacking between states. In addition, states were working on plans for receiving and distributing the Strategic National Stockpile and for administering mass vaccinations. States and local areas were addressing gaps in public health preparedness elements, such as communication, but weaknesses remained in other preparedness elements, including the disease surveillance and laboratory systems and the response capacity of the workforce. Gaps in capacity often are not amenable to solution in the short term because either they require additional resources or the solution takes time to implement. We found that officials were beginning to address communication problems. For example, six of the seven cities we visited were examining how communication would take place in a public health emergency. Many cities had purchased communication systems that allow officials from different organizations to communicate with one another in real time. In addition, state and local health agencies were working with CDC to build the Health Alert Network (HAN), an information and communication system. The nationwide HAN program has provided funding to establish infrastructure at the local level to improve the collection and transmission of information related to public health preparedness. Goals of the HAN program include providing high-speed Internet connectivity, broadcast capacity for emergency communication, and distance-learning infrastructure for training. State and local officials for the cities we visited recognized and were attempting to address inadequacies in their surveillance systems and laboratory facilities. Local officials were concerned that their surveillance systems were inadequate to detect a bioterrorist event, and all of the states we visited were making efforts to improve their disease surveillance systems. Six of the cities we visited used a passive surveillance system to detect infectious disease outbreaks. However, passive systems may be inadequate to identify a rapidly spreading outbreak in its earliest and most manageable stage because, as officials in three states noted, there is chronic underreporting and a time lag between diagnosis of a condition and the health department’s receipt of the report. To improve disease surveillance, six of the states and two of the cities we visited were developing surveillance systems using electronic databases. Several cities were also evaluating the use of nontraditional data sources, such as pharmacy sales, to conduct surveillance. Three of the cities we visited were attempting to improve their surveillance capabilities by incorporating active surveillance components into their systems. However, work to improve surveillance systems has proved challenging. For example, despite initiatives to develop active surveillance systems, the officials in one city considered event detection to be a weakness in their system, in part because they did not have authority to access hospital information systems. In addition, various local public health officials in other cities reported that they lacked the resources to sustain active surveillance. Officials from all of the states we visited reported problems with their public health laboratory systems and said that they needed to be upgraded. All states were planning to purchase the equipment necessary for rapidly identifying a biological agent. State and local officials in most of the areas that we visited told us that the public health laboratory systems in their states were stressed, in some cases severely, by the sudden and significant increases in workload during the anthrax incidents in the fall of 2001. During these incidents, the demand for laboratory testing was significant even in states where no anthrax was found and affected the ability of the laboratories to perform their routine public health functions. Following the incidents, over 70,000 suspected anthrax samples were tested in laboratories across the country. Officials in the states we visited were working on other solutions to their laboratory problems. States were examining various ways to manage peak loads, including entering into agreements with other states to provide surge capacity, incorporating clinical laboratories into cooperative laboratory systems, and purchasing new equipment. One state was working to alleviate its laboratory problems by upgrading two local public health laboratories to enable them to process samples of more dangerous pathogens and by establishing agreements with other states to provide backup capacity. Another state reported that it was using the funding from CDC to increase the number of pathogens the state laboratory could diagnose. The state also reported that it has worked to identify laboratories in adjacent states that are capable of being reached within 3 hours over surface roads. In addition, all of the states reported that their laboratory response plans had been revised to cover reporting and sharing laboratory results with local public health and law enforcement agencies.