Since the anthrax mailings of 2001, policymakers have been implementing programs todecrease the vulnerability of the United States to terrorist use of biological weapons. This reportdiscusses high-threat biological agents, focusing on the Centers for Disease Control and Prevention(CDC) definition for Category A pathogens (bacteria and viruses), their treatment and detection,current policies, and possible future approaches to reducing their threat. Terrorist use of biologicalagents would be a low probability, but potentially high consequence, event. While there is stilldebate over whether terrorist groups have the ability to effectively use biological weapons as aweapon of mass destruction, the anthrax mailings of 2001 highlighted their potential as a terrorweapon. Policy approaches for reducing vulnerability to biological terrorism involve bothaddressing biological agents as a group, and focusing on specific agents perceived as posing thegreatest threat. Treatments for exposed victims vary depending on the nature of the pathogen andexperience in treatment of these diseases is limited, due to the rarity of naturally occurring cases. Biological agents, for the purposes of this report, are pathogens which can infect and causeserious illness in humans. (1) The level of threat abiological agent may constitute is open tointerpretation. Depending on what aspects of a pathogen are considered priorities, differentbiological agents are likely to be identified as high threat. For example, the National Institute ofJustice provides an extensive list of biological agents of concern in their handbook on purchasingprotective equipment. (2) , (3) In comparison, handbooks regarding battlefieldtreatment of biologicalweapon casualties contain a shorter list of agents. (4) The CDC identifies a number of differentcategories of biological agents, and rank the various biological agents into categories. Category A diseases -- anthrax, plague, smallpox, tularemia, and viral hemorrhagic fevers --are of the highest threat. (5) The CDC views CategoryA pathogens as easily disseminated ortransmitted from person to person; resulting in high mortality rates; having the potential for majorpublic health impact; potentially causing public panic and social disruption; and requiring specialaction for public health preparedness. This is in contrast to the Category B agents which lack suchpotential. (6) The Category A pathogens will bediscussed in this report. Anthrax is a disease caused by the bacterium Bacillus anthracis . (7) Bacillus anthracis respondsto environmental stresses, such as nutrient depletion or oxygen exposure, by forming spores. Whilethe bacterium is dormant in spore form, these spores are very hardy and can remain viable fordecades in ideal conditions. Anthrax spores are primarily found in soil, and are endemic to manyparts of the world. Anthrax is primarily an animal disease, infecting animals when they ingest Bacillus anthracis spores during grazing. Anthrax is not a person-to-person contagious disease. The forms of anthrax infection are cutaneous, intestinal, and inhalation. The type of anthrax infection depends on how the victim came into contact with the spores. Cutaneous anthrax is themost common form of the disease and occurs when anthrax spores contact broken skin. Intestinalanthrax occurs after consumption of anthrax-spore-contaminated food, usually meat. Intestinalanthrax is less common than cutaneous anthrax. Inhalation anthrax is the least common naturallyoccurring form of anthrax. Inhalation anthrax occurs when spores are inhaled and germinate in thelungs. The symptoms usually appear 48 to 72 hours after exposure. The effects of the three forms of the disease, differ from each other drastically. Cutaneous anthrax is marked by a swollen, painlessblack ulcer where the infection occurred. In contrast, intestinal anthrax is characterized by nausea,vomiting, and fever followed by abdominal pain, vomiting of blood, and severe diarrhea. Inhalationanthrax manifests with symptoms resembling a common cold: fever, fatigue, and a dry cough. Thesymptoms progress to severe difficulty breathing and shock as the bacteria multiply. The recovery rate for anthrax infection depends both on type of infection and how early treatment begins. Early treatment of anthrax victims is strongly suggested, as late treatment is notas effective in many cases. Cutaneous infection typically has a fatality rate of less than 5% with earlytreatment, increasing to 20% without any treatment. Intestinal anthrax has a higher mortality rate,with fatalities ranging from 25% to 75% depending on effectiveness of treatment. Some medicalexperts assert that aggressive early treatment of intestinal anthrax will lower the fatality rate. (8) Untreated inhalation anthrax is almost uniformly fatal. With early treatment within the incubationperiod, the fatality rate can be dramatically reduced. In the aftermath of the anthrax mailings of2001, 5 of the 11 people diagnosed with inhalation anthrax died, but historically greater than 90%of inhalation anthrax cases have been fatal, even with treatment. (9) All forms of anthrax are treated with antibiotics. Several different antibiotics may be used, including ciprofloxacin, penicillin, and doxycycline. Some anthrax strains may be less sensitive toantibiotics and therefore difficult to treat. Prophylaxis is available to protect against anthrax both via vaccination and post-exposure antibiotic treatment. While a vaccine against anthrax has been licensed by the FDA, it is notcurrently available to the general public due to vaccine shortage. The Department of HomelandSecurity, working with the Department of Health and Human Services and other federal agencies,is coordinating development of civilian anthrax vaccine policy. The Department of Defense anthraxvaccination policy, and the amount of vaccine needed to implement this policy, includes vaccinationof troops thought to be potentially exposed to anthrax. (10) After the anthrax mailings of 2001, thoseindividuals thought to be potentially exposed to anthrax spores were offered vaccination andantibiotic prophylaxis using the drug ciprofloxacin. Plague is a disease caused by the bacterium Yersinia pestis . Plague bacteria are sensitive to sunlight and humidity and do not form spores. Instead, plague bacteria naturally reside in hostcreatures, such as rodents, and are found in many parts of the world, including the United States. Plague usually travels within animal populations, via insect vectors, generally migrating from oneanimal to another through biting insects such as fleas. The three kinds of plague are bubonic, septicemic, and pneumonic. Bubonic plague and septicemic plague occur when plague bacteria enter the body through the bite of an infected insect. Pneumonic plague occurs when plague bacteria are inhaled into the lungs, or develops out of abubonic or septicemic infection. Pneumonic plague, unlike the other forms, does not have to passthrough an insect vector. It is person-to-person contagious. Bubonic plague is the most well-known form. It is also known as the Black Death, and was responsible for the European plagues of the 14th century. Victims of bubonic plague developswollen, painfully inflamed lymph glands, (11) andalso suffer fever, headache, chills, and generalweakness. Septicemic plague occurs in a manner similar to bubonic plague, except the swelling ofthe lymph glands does not occur. Instead, the bacteria multiply in the blood, causing shock andinternal bleeding in addition to the more general symptoms of fever and weakness. The symptomsof pneumonic plague include fever, weakness and cough, possibly combined with severe nausea,abdominal pain, diarrhea, and difficulty breathing. The recovery rate for treatment of the different forms of plague vary. Naturally occurring plague in the United States has an overall fatality rate of 14%. The majority of these cases arebubonic with some septicemic, and very rarely pneumonic, plague. The fatality rate for septicemicplague is markedly higher than that for bubonic (33% versus 11% between 1980-1984), (12) mainlyascribed to difficulties in diagnosing septicemic plague at an early stage. Pneumonic plague has amuch higher fatality rate. It approaches 100% as the time between infection and treatment increases. For effective treatment, therapy must begin within 18 hours or victims are not likely to survive. (13) For untreated forms, the fatality rate is 60% for bubonic plague and 100% for septicemic andpneumonic plague. All forms of plague are treated using antibiotic therapy. The Food and Drug Administration has approved several antibiotics for treatment of plague, and others not yet approved for such havebeen shown to be effective. Natural antibiotic resistance in plague bacteria is known, so not all casescan be cured using a single antibiotic. (14) A plague vaccine has been approved for human use, but its production was discontinued in 1998 because of manufacturing difficulties. Additionally, the vaccine was not effective againstpneumonic plague, limiting its utility. Several Investigational New Drug (IND) vaccines are underdevelopment. (15) Smallpox is a disease caused by the virus variola. Naturally occurring variola virus has been eradicated, and the only remaining, legal stocks of the virus are held at secured facilities in theUnited States and Russia. (16) Smallpox is aperson-to-person contagious disease. Typical victims of smallpox suffer an outbreak of rash, followed by scabbing pustules covering their body. The rash and pustules form over a three week period following an incubation time ofapproximately one to two weeks. Survivors of smallpox are generally scarred by the disease. Thedisease has two rare variants; one is known as flatpox, the other hemorrhagic smallpox. (17) The fatality rates for the forms of the disease differ. For smallpox, the fatality rate is approximately 30%, though in a population lacking natural resistance this rate may increase. Bothflatpox and hemorrhagic smallpox have a fatality rate approaching 100%. Smallpox has no specific treatment, though vaccination after exposure may reduce the severity of the disease. An approved vaccine which protects against smallpox is known, but it is notavailable to the general public. This vaccine has recently been offered to select first responders andmembers of the military. For more information regarding the smallpox disease and vaccination, see CRS Report RS21288 , Smallpox: Technical Background on the Disease and Its Potential Role inTerrorism by [author name scrubbed] and CRS Report RL31694 , Smallpox Vaccine Stockpile and VaccinationPolicy by [author name scrubbed]. Tularemia is a disease caused by the bacterium Francisella tularensis . Tularemia bacteria are fairly hardy, surviving for weeks in the environment, and naturally reside in host creatures, such asrodents. Tularemia bacteria are found in many parts of the world, including the United States. Tularemia, like plague, can be transferred between animals via biting insects. Naturally occurring cases of tularemia arise from the bite of an infected insect, eating contaminated food or water, or breathing aerosols of bacteria. (18) Tularemia bacteria are veryinfectious, requiring very few bacteria to cause disease. The different forms of exposure to tularemiabacteria lead to different symptoms. Those who ingest contaminated food or are bitten by infectedinsects may develop swollen and painful lymph glands and eyes, sore throat, or skin lesions. Victimsexposed to aerosolized tularemia bacteria develop symptoms similar to pneumonia: weakness, fever,aches, cough, and chest pain. Tularemia has an incubation period of 3 to 5 days after exposure. The recovery rate for tularemia depends on access to proper treatment. Untreated tularemia has a fatality rate of 60%, but with proper treatment the fatality rate can be reduced to 2%. Tularemia can be treated using antibiotic therapy, but reportedly strains of F. tularensis have been successfully engineered to be antibiotic resistant. (19) Several antibiotics are approved by theFDA to treat tularemia, and other antibiotics have been shown to be successful against the disease. Tularemia lacks an approved vaccine, though several IND vaccines are undergoing testing. One IND vaccine has successfully been used to protect laboratory personnel against inadvertent aerosolexposures. (20) Viral hemorrhagic fevers are caused by viruses of the filovirus and arenavirus family. These fevers include Ebola and Marburg. (21) Theseviruses are rarely encountered and are believed to befound in natural animal reservoirs, though the exact nature of some of the reservoirs is unknown. Viral hemorrhagic fever viruses are not especially hardy, and are generally transmitted throughcontaminated body fluids, such as blood. (22) Viral hemorrhagic fever symptoms depend on the exact disease, but most include fever, muscle aches, and exhaustion. Severe cases of viral hemorrhagic fever also involve internal bleeding, orhemorrhage from the mouth, eyes, or ears. Blood loss is not the common cause of death, but ratherfailure of internal organs. The recovery rate for viral hemorrhagic fevers varies from 30% to 90%, depending on the exact disease. Since many fevers occur in developing countries, these recovery rates may not berepresentative of aggressive medical treatment. Viral hemorrhagic fevers encountered in the UnitedStates may have a higher recovery rate due to more advanced supportive treatment. Viral hemorrhagic fevers have no established treatments besides supportive care, though some medications are recommended against specific diseases. For example, animal and clinical studieshave shown that ribavirin, an anti-viral drug, has some efficacy against Lassa fever andCrimean-Congo hemorrhagic fever, and could be used under IND status. Investigation into vaccines for viral hemorrhagic fevers is ongoing. (23) Vaccines have beendeveloped that provide protection against some. With the exception of one for yellow fever, thesevaccines are not commercially available in the U.S. Access to these vaccines is limited, andprovided under IND protocols. Protection against biological agents may be achieved through either physical or medical means. Personal physical measures limit exposure by protecting the eyes, lungs, and/or skin from biologicalcontact and preventing contact with insect vectors. Medical protection may be effective when thebiological agent responds to drug treatment or when an available, effective vaccine exists. Personal physical protection against biological agents includes masks and protective clothing. Protective masks filter the air inhaled by the wearer, removing particles from the air. The mosteffective filters can remove almost 100% of aerosol particles greater than one micron in size. Byblocking inhalation of pathogens, disease is avoided. Protective garments, in the context of biological agents, are generally designed to minimize inadvertent self-contamination with pathogen. Protective gloves, disposable overgarments, and, insome cases, face shields provide requisite protection from victims of contagious pathogens. Such personal physical protections are used by medical professionals in the treatment of victims of viral hemorrhagic fevers. Isolation and barrier methods provide medical professionals withprotection from infection. In extreme cases, additional precautions to avoid aerosol inhalation maybe required. (24) Medical protection against pathogens takes two tacks. One is the pre-exposure vaccination of populations potentially at risk. For example, troops in the Middle East have been vaccinated againstsmallpox and anthrax as protection against potential military use. The other is the prophylactic useof antibiotics following known exposure to a pathogen. This method was used after the anthraxmailings of 2001. The availability of an effective, licensed vaccine is a requirement for protective pre-exposure vaccination. For the high-threat biological agents found on the CDC Category A listing, fewvaccines are available. Licensed vaccines exist for both anthrax and smallpox, but these vaccinesare not in public distribution. Due to national security needs, anthrax vaccine is being used toinnoculate military personnel, and a sufficient supply of vaccine has not become available to offervaccination to the general public. Recently, the supply of the smallpox vaccine has become suchthat, in extremis, the entire population of the United States could be vaccinated. Not all high-threatbiological agents have a licensed vaccine, but some have IND-stage vaccines which might be usedin emergency situations. Use of IND vaccines might be complicated by supply concerns, as onlysmall amounts of these vaccines exist. Prophylactic use of antibiotics is only successful against bacteria. Viruses are not sensitive to antibiotics, and so antibiotic use will not provide protection. Because the treatment of many bacteriais most effective when treatment is begun at an early stage, prophylactic use of antibiotics is usuallyrecommended for those potentially exposed. The detection of pathogens, especially in the case of a covert release, is a complicated process. When victims of a release are hospitalized, identification of the causal pathogen may quickly occur,as the combination of symptomatic patients and ready access to large amounts of the pathogenprovide much information towards its identification. (25) But, in the instance of suspected, small-scalereleases, identification, and even detection, of a pathogen release may be difficult. Biological agentsare difficult to quickly detect, generally requiring laboratory work-up to detect and identifypathogens. It may require several hours, at the minimum, to detect and definitively identify specificpathogens. On the other hand, these laboratory-based, molecular biology techniques are extremelysensitive and can detect very small amounts of pathogen. The methods used to detect pathogensinvolve analysis of the pathogen's genetic sequence or enzymatic reaction. Scientists are workingto develop faster techniques for both detection and analysis. President Bush, during remarks to new employees of the Department of Homeland Security, announced the establishment of the BioWatch initiative. (26) This initiative consists of deploying earlywarning sensors in locations across the nation to help detect biological attacks. This prototypeatmospheric monitoring system is being put in place using EPA air quality monitors. (27) Themonitoring system consists of sampling equipment which collects particles present in theatmosphere. The material collected is brought to a laboratory setting, analyzed, and tested forspecific pathogens. In theory, the laboratory results from this process could be available in as littleas 12 hours. (28) It is reported that the laboratorieswhich take part in the Laboratory Response Networkwould be involved in performing detection and analysis of these pathogens. (29) Research anddevelopment of further refinements of such monitoring technology is underway. (30) Other commercial systems have been purchased and installed to detect airborne pathogens and toxins. For example, the city of Honolulu has purchased and deployed six stationary air monitorswithin the island of Oahu. (31) The U.S. PostalService is reportedly testing an indoor system to detectairborne biological agents. (32) If effective, iteventually will be installed in all 282 mail-processingplants nationwide to protect postal workers. The field detection of biological agents is usually performed with screening devices which detect specific pathogens. Typical screening devices use antibody tests or fast, genetic tests usingpolymerase chain reaction (PCR) to provide a rapid diagnostic for the presence of a given biologicalagent. Antibody tests are agent specific, so different biological agents require the use of differentantibody tests. PCR screens determine if genetic markers are present, linking the test sample to aknown pathogen. Screening tests have varying sensitivity. For some highly infectious pathogens,the detectable concentration of pathogen may be significantly greater than the infectious dose. (33) Consequently, such field devices are not generally considered definitive tests for the absence of anagent, but rather are used to confirm the presence of significant quantities of agent. Furtherdevelopment of field devices is ongoing. (34) Subsequent to an initial screening test, samples are sent to laboratories, where more sensitive laboratory tests are used to ascertain the identity of any pathogen present. In general, samples, eventhose that test negative through screening tests, require laboratory-based confirmatory analysis. Theburden of this process on the public health laboratory system has been heavy. (35) Monitoring the public health has emerged as a potentially important method in detecting the covert release of pathogens. The Centers for Disease Control and Prevention, in conjunction withthe Department of Defense, the Association of Public Health Laboratories, and others, have upgradedthe Laboratory Response Network, which connects hospitals, public health laboratories, and otherresources to monitor and track disease outbreaks. (36) It has been suggested that the first sign of acovert pathogen release by terrorist groups may be a sudden increase in the number of hospitalpatients exhibiting symptoms. By analyzing information from such patients, a likely time andlocation of pathogen release might be discovered and consequence management plans invoked. Some cities have further expanded these programs by monitoring purchases related to the public health. For example, some cities track pharmaceutical and other medicinal sales, operating on thetheory that this will provide even earlier detection than hospital arrivals. (37) It is expected that theearly identification of a disease outbreak will increase the treatment success and consequently lowerthe fatality rate. The likelihood of terrorist use of biological agents as a weapon of mass destruction is an areaof great debate. Biological agents have not been used to cause mass casualties in modern times, andare incapable of destroying physical infrastructure. This raises questions about the claim that theywould be effective weapons of mass destruction. The technical feasability of terrorist groupsdisseminating biological agents is also open to question. Some believe that the techniques andtechnologies required for processing and disseminating biological agents are beyond the capabilitiesof a terrorist group, while others believe that terrorist groups wishing to use biological weaponscould easily do so. In contrast to chemical agents, few biological agents are commercially availablein large quantity, and so are not readily available for purchase or theft. On the other hand, biologicalagents are naturally occurring and self-replicating, which may ease the difficulties of acquiring andmanufacturing sizeable quantities. Because pathogens are self-replicating, very small amounts can cause infection. Large quantities are not required to cause mass casualties. It has been estimated that approximately 100lbs. of anthrax spores efficiently and uniformly disseminated by airplane under ideal conditions ina metropolitan area could cause 150,000 casualties. (38) Terrorist groups have shown interest in biological weapons, but few examples of their successful use, and none as a weapon of mass destruction, exist. One well-known example ofbiological-weapon use within the United States was by the Rajneeshee cult in 1984. There,salmonella bacteria was disseminated through intentional contamination of salad bars. Severalhundred people were made ill over a number of weeks. (39) The Aum Shinrikyo cult also attemptedto develop biological weapons. While more well-known for their chemical weapon attack in theTokyo subway system in 1995, they cultured and attempted to disseminate Bacillus anthracis byaerosolizing a liquid slurry of anthrax culture. The anthrax disseminated was an avirulent strain andconsequently no casualties occurred. (40) Whether terrorist groups would choose biological weapons is unclear. Some have asserted that such use would be incompatible with political goals that terrorist groups have, e.g. formation of anation-state. Others claim that a new stage of superterrorism has begun, with the attacks ofSeptember 11th being indicative of a greater willingness of terrorist groups to intentionally causemass casualties. For more information on the motivation of terrorist groups with respect tobiological and chemical weapons, see CRS Report RL31831 , Terrorist Motivations for Chemicaland Biological Weapons Use: Placing the Threat in Context by [author name scrubbed]. Weapons of terror, in contrast to weapons of mass destruction, may cause few casualties but rather instill panic because of frightening aspects of their use. Some argue that the use of biologicalagents as weapons of terror would require little infrastructure and be an effective use of even limitedsupplies of pathogen. They claim that release of small amounts of biological agent might cause alevel of panic disproportionate to the actual amount released, and point to the anxieties raised afterthe mailings of the anthrax letters of 2001 as emblematic of the type of response that can begenerated by small-scale use of biological weapons. Others assert that the significant investment oftime, money, and trained personnel which would be required to develop even small amounts ofpathogen provides a serious disincentive to terrorist groups. They state that terrorist groups are muchmore likely to use conventional weapons than any weapon of mass destruction. The anthrax mailings of 2001 highlighted the vulnerability of the United States to biological attack, and reignited public interest in bioterrorism and domestic preparedness. A series of letterscontaining freeze-dried anthrax of varying coarseness were sent through the U.S. Postal Service totwo U.S. Senators and two news outlets. The anthrax spores contaminated postal equipment duringmail processing and subsequently infected postal workers with inhalation anthrax. Questionsregarding the identity of the mailer, the motivations of the mailer, and the origin of the anthraxspores remain unanswered. For more information on the anthrax mailings and the US PostalServices response, see CRS Report RL31280(pdf) , The U.S. Postal Service Response to the Threat ofBioterrorism Through the Mail by [author name scrubbed]. Current federal policy regarding biological weapons is a combination of nation-state levelcontrols, increased domestic regulation, and accelerated research and development of medicines,vaccines, and detectors. Additionally, professional societies have increased self-monitoring actions. The United States maintains export policies with respect to selected pathogens and biological dual-use equipment, primarily through the multilateral Australia Group and the WassenaarArrangement. U.S. export controls aimed at creating proliferation barriers include ExportAdministration Regulations and International Traffic in Arms Regulations. (41) These export controlsare designed to inhibit nation-state level acquisition and proliferation of biological weapons. Because of the commercial ubiquity of equipment potentially capable of producing biologicalweapons, experts consider it difficult to block terrorist groups from developing small-scaleproduction capability solely through export controls. (42) Use, possession, and transfer of high-threat biological agents is now increasingly regulated due to the USA PATRIOT Act ( P.L. 107-56 ) and the Bioterrorism Preparedness and Response Act ( P.L.107-188 ). (43) Only persons with a bona fide needfor them are allowed to possess or use biologicalagents on the Select Agent list. (44) Additionally,university researchers experimenting on Select Agentpathogens are required to pass a background check by the FBI. (45) Individuals who are citizens of thecountries formally declared as sponsors of terrorism are not allowed access to these pathogens. The Food and Drug Administration has altered selected rules governing the degree of testing necessary before approving human-use of drugs. (46) In cases where testing effectiveness on humanswould be unethical, drug approval could be made based on the efficacy results from animal testing. Generally, vaccines and medicines used by humans require full human testing. Some have advocatedthat foregoing human clinical trials would speed development of new treatments against bioterroragents, and potentially increase the amount of private sector research money invested in bioterrordefense. (47) Defense against bioterrorism has spurred research and development activities. The Department of Homeland Security has an active role in biological countermeasure development, while theDepartment of Health and Human Services continues to be at the forefront of bioterrorism researchand development. Research into new treatments and vaccines, detector sensitivity andminiaturization, decontamination, and pathogen properties are being performed. Biomedical Research. The federal government performs and funds research and development of biodefensive measures. Such research includesdiscovery of new vaccines and treatments, research into countermeasures against biological weapons,as well as research into more fundamental, basic science, such as pathogen genetics and the originsof virulence. The National Institutes of Health administers the bulk of the Department of Health andHuman Services biomedical research funding, while the DARPA Biological Warfare Defenseprogram and the Joint Service Chemical and Biological Defense Program is funded by theDepartment of Defense. Development of biological countermeasures and efforts to reduce theimpact of a biological terror attack is performed through the Department of Homeland Security'sDirectorate of Science and Technology as well. Federal research on high-threat pathogens isperformed at the U.S. Army Medical Research Institute of Infectious Diseases laboratory at FortDetrick, Maryland, and the Centers for Disease Control and Prevention laboratory in Atlanta,Georgia. Increasing Detector Accuracy and Sensitivity. Detecting and identifying pathogens is an area of continued research. The ability of first respondersto identify biological agents when first encountering them is key to identifying appropriate treatmentfor victims. Sensitive, rapid detection systems are under development in the private sector as wellas the Department of Energy's National Laboratories. New detectors based on different detectionmethods are being investigated to ascertain their capabilities. The military, while already possessinglarge, platform-based detection capabilities, is developing a new detection system, the JointBiological Agent Identification and Diagnostic System (JBAIDS), which will allow for fast, portabledetection of biological agents. Miniaturization. In concert with the need for more sensitive, accurate detectors, reducing the size of such detectors is also an area of currentresearch. Technologies currently employed for analyzing the atmosphere for pathogens tend to belarge and complex. The goal of a compact, ideally easily portable, detector system drives researchefforts in detector miniaturization. The National Science Foundation, the Department of Energy, andthe Department of Defense have all funded programs to develop smaller, handheld instruments todetect biological pathogens in the environment. Better Understanding of Diffusion of Biological Releases. Understanding how an aerosol release might travel is another area whereresearch occurs. Computer modeling of aerosol properties, wind flow in urban settings and withinbuildings, and the effects of initial conditions on final particle distribution all may lead to moreeffective incident response and consequence management. The Department of Health and HumanServices uses such modeling in its emergency response command center to help develop andprioritize response to a chemical or biological release. (48) Research in this area is conducted at theNational Laboratories, among other places. Decontamination. After the anthrax mailings, the Hart Senate Office Building required extensive decontamination to remove the residual anthraxspores. Methods for decontaminating office buildings have not been widely tested, anddecontamination of the Hart Building using chlorine dioxide cost an estimated $42 million. Thecleanup of the contaminated Brentwood facility, in Washington, DC, and the Hamilton Township,New Jersey, facility is reportedly expected to cost over $150 million. (49) Research is underway todevelop less costly methods of decontaminating areas from biological agents and to assess theeffectiveness of current decontamination methods. The federal government has historically supported the open publication of federally funded research results, but a series of research publications in molecular biology have increased concernsover whether publication of certain federally funded extramural research results could threatennational security because of their possible usefulness to terrorist groups. Some have suggested thatfederally funded extramural research results should be reviewed for their security implications priorto their publication in the open literature, while others have asserted that such review would bedamaging to scientific progress and productivity. If such review is deemed necessary, an openquestion remains as to who would review these research results and at what point in the researchprocess they would be reviewed. Some publishers have begun to implement self-regulatorymeasures regarding publication of potentially sensitive manuscripts, but such steps have not beenapplied industry-wide. Others claim that such a review process might be most effective if performedby a federal agency. For more information, see CRS Report RL31695 , Balancing ScientificPublication and National Security Concerns: Issues for Congress by [author name scrubbed] and CRS Report RL31845 , "Sensitive But Unclassified" and Other Federal Security Controls on Scientific andTechnical Information: History and Current Controversy by [author name scrubbed]. Significant investment in the public health system has been made to prepare the medical community to respond to a bioterror event. This has included additional funding from the CDC forthe development of bioterror response plans and increasing the preparedness of hospitals and otherfacilities for bioterror casualties. Additionally, the National Strategic Stockpile, formerly called theNational Pharmaceutical Stockpile, has been expanded to contain antibiotics, medical treatments,and antidotes. (50) While there are still critics ofthe current state of preparedness for a biologicalattack, (51) Secretary of Health and Human ServicesThompson has stated that the country is wellprepared to respond to possible bioterrorism attacks. (52) For a comprehensive overview, see CRS Report RL31719 , An Overview of the U.S. Public Health System in the Context of Bioterrorism by[author name scrubbed]. Numerous federal response teams could be deployed in the event of biological terrorism. In general, these teams would support local responders in detection, decontamination, or treatmentroles. (53) A selection of these federal teams isdescribed below. One response team is the DOD's Chemical/Biological Incident Response Force (CBIRF). (54) CBIRF can be deployed to aid in consequence management after a chemical or biological terrorattack. It possesses both decontamination and treatment facilities and can be deployed domesticallyor internationally at short notice. This rapid response force was on hand for the Atlanta Olympicsin 1996 and is equipped with state of the art equipment for dealing with chemical and biologicalthreats. It is located at Indian Head, Maryland, and could be deployed in the case of biological orchemical terrorism. (55) The FBI maintains a Hazardous Materials Response Unit which, in response to crimes involving biological weapons, would be available to analyze and identify pathogens and other threatspresent. This unit provided protocols for handling evidence during the anthrax mailings of 2001. (56) The U.S. Army Technical Escort Unit conducts biological detection, decontamination, and removal of biological devices or hazards woldwide. While commonly deployed to handle and securediscovered biological munitions, they also have been used to provide support to other large nationalevents. (57) As part of the National Disaster Medical System, Disaster Mortuary Operational Response Teams, Disaster Medical Assistance Teams, and four National Medical Response Teams areavailable to be deployed to the scene of a national emergency. This program was transferred to theDepartment of Homeland Security on March 1, 2003. (58) The National Guard supports several Weapons of Mass Destruction Civil Support Teams. They were established to support local resources in determining the nature and extent of an attack orincident. These teams are able to deploy within four hours of a given alert. A topic of potential interest to policymakers is oversight of the federal government's development of biological countermeasures. Such countermeasures include, but are not limited to,new detectors, treatments, medical prophylaxis, and physical protection from biological agents. While the Department of Health and Human Services has been designated the lead agency inproviding bioterrorism research and development, the Department of Homeland Security has beengiven a role in setting priorities. In FY2004 budget, $266 million has been appropriated for DHS'Science and Technology Directorate's biological countermeasures programs. How the Departmentof Homeland Security will assist in setting priorities for HHS research, and how the new HomelandSecurity Advanced Research Projects Agency (HSARPA) will prioritize research it funds, are notcurrently well understood. Because high-threat biological agents include both viral and bacterial agents, a single treatment will not be successful against all illnesses. Some have suggested that research into new antiviral andantibiotic compounds for use against biological agents might provide additional health benefits, asthese compounds may prove to be effective medications for other, more common illnesses. Becauseof the shortage of licensed vaccines for many high-threat pathogens, development of new vaccineshas been an area of congressional interest. The lack of a civilian market for biological weaponvaccines has inhibited private sector investment and production of these products. Since the naturalincidence of disease from biological-weapon pathogens is rare, and disease form is often differentthan that expected to result from a bioterror attack, there has been little impetus to develop andmarket these vaccines. Some have suggested that the federal government should take a role inproviding research incentives and a guaranteed market for any vaccines against biological weapons. A variety of mechanisms have been suggested, including expedited drug approval processes, taxincentives, liability protections, and expanded procurement practices. A form of expedited drugapproval has already been implemented by the FDA for drugs involved in biodefense; it requiresfewer animal studies before approval is given for human use. (59) For more information on federalvaccine policies, see CRS Report RL31793 , Vaccine Policy Issues for the 108th Congress by SusanThaul and CRS Report RS21414 , Mandatory Vaccinations: Precedent and Current Laws by AngieA. Welborn. President George W. Bush, in the 2003 State of the Union address, announced a new proposal called Project BioShield. This proposal provides for expedited acquisition authority,non-competitive procurement, and purchase of potential biological countermeasures up to 5 yearsprior to their licensing. For more information on Project BioShield, see CRS Report RS21507 Project BioShield by [author name scrubbed]. The deployment of the BioWatch prototype biological agent detector has raised questions about how this system will be used. Such a monitoring system for covert releases of biological agents mayprovide important early notification of potential danger. Since many pathogens have an incubationperiod of several days, it is often difficult to begin treatment at an early stage. Early treatment of theinhalation form of these diseases is essential to recovery, and a system that signaled pathogen releasebefore the appearance of symptoms in victims would be likely to increase the ability of victims toreceive medication and survive. By employing an array of such sampling devices, a city-widenetwork might detect pathogen releases in smaller amount and also aid in determining the epicenterof a release. Such information may be important to identify the perpetrators of such an attack. Since the BioWatch detectors are coupled to EPA air quality monitors, the locations are determined by air quality considerations, and it is not readily apparent that these locations willprovide adequate sampling of populated areas. If the air quality monitor is located well above streetlevel, it may not detect the release of biological agents at street level. Additionally, the effectivenessof these detectors in identifying small releases or indoor release of biological agents is notestablished, and so placement of these detectors may provide a false sense of security. Such adetection system may also detect naturally occurring biological agents which are not virulent. Forexample, anthrax spores naturally occur in some areas of the United States, and may provide falseindications of small-scale covert release. The continued cost of these detectors, reported at $1million per detector per year, is also of concern. An unknown aspect of the BioWatch program is the range of detector coverage. It has been reported that each metropolitan area chosen will have 10 to 12 distinct detectors built into differentair quality monitors. Also, a reported goal of this program is to provide detection for "80% of theAmerican population by geographic distribution." (60) Since the EPA air quality monitors are notevenly spread throughout the various geographic areas of the country, it is not apparent whether theBioWatch program will be expanded to other sorts of monitoring stations. Development and production of easily portable or handheld biological detection apparatus is another area where a pressing need has been identified. Antibody tests and methods usingrecognition of pathogen genetic sequences only detect specific pathogens. Unexpected pathogens,either rare or genetically modified, may elude current detection equipment. Consequently,policymakers may decide to direct funding towards development of either a broad assortment ofinexpensive testing equipment or expanding the range of pathogens a given device can detect. Asmore pathogen-specific detectors become available, the cost of testing per incident may increase, asmore pathogens are potentially screened, but may decrease as more detectors are manufactured anddistributed. Policymakers may choose to address current methods of detecting bioterror events. Tracking potential bioterror releases through monitoring hospital admissions and physician reports may indeeddetect a covert pathogen release, but such an approach requires that individuals first fall ill from thepathogen release. Critics claim that in the case of a contagious pathogen, such as pneumonic plagueor smallpox, the spread of the disease will occur at a rate greater than the government response, asthere will be a time delay due to the incubation period of the disease. Thus, there will be anexpanding number of people being infected even as public health workers attempt to determine theepicenter of the release. Such an argument has been made especially in the case of smallpox, astreatment for smallpox, once symptoms have begun to appear, is unavailable. In the smallpox case,the debate over which vaccination method should be used, the ring vaccination model based onidentifying the initial outbreak of the disease and then vaccinating contacts of the victims of theinitial outbreak, or the mass vaccination model, where people in a geographic area are innoculatedif smallpox is detected, has been very lively. Advocates of establishing sensors to detect pathogenreleases, before victims begin to seek treatment, claim that the earlier the detection of an outbreak,the more effective treatment will be. Others have asserted that the current model will be effective in limiting casualties from a pathogen release. They claim that increases in the public health infrastructure have reduced thelikelihood that hospitals and care-providers would be overwhelmed by a bioterror event. While notrejecting the utility of developing other detection devices to warn of a covert pathogen release, somescientists modeling pathogen releases have stated that even reducing detection times from 48 to 6hours after release would not reduce overall casualties as much as an effective, efficient public healthresponse and treatment. (61) The amount of funds the federal government should provide to first responders and whether all first responders should have standardized equipment is a topic of congressional interest. (62) Firstresponder equipment is currently not nationally standardized, with each jurisdiction purchasing itsown equipment. Some first responder teams feel well-equipped and prepared for a potentialbiological attack, while others do not yet have necessary equipment. (63) While the National Instituteof Justice has provided a manual outlining the criteria by which biological equipment might beassessed, (64) some first responders have claimedthat the federal government has not provided enoughoversight and direction regarding such esoteric purchases. (65) Advocates of allowing each communityto choose what equipment to provide to first responders point out that the needs of one communitymay not be the same as the next, and, because of location, population, or previous expenditures,mandating specific equipment purchases may not meet specific locality needs. (66) The Departmentof Homeland Security is slated to develop a Standards Program to develop test and evaluationcriteria and conduct analyses for first responder detection equipment to help provide more guidancefor first responder purchases. Policymakers may ultimately determine the adequacy of current firstresponder equipment and its availability, the amount of funds that first responders should receive topurchase protective equipment, whether proper guidance has been given by the federal governmentto state and local authorities regarding this equipment, and what steps may be required, throughoversight or legislation, to properly equip first responders. The use of federal response teams to augment local first responder capabilities has been questioned. While an investigation by the General Accounting Office in 2000 found that "Federalresponse teams do not duplicate one another," (67) there have been concerns that the varied teamsestablished by these agencies may be redundant. (68) Also, the general structure of establishing regionalteams has been questioned, since there would be a delay in response due to required travel time fora team. (69) On the other hand, others haveadvocated that parallel civilian and military response teamsmay be necessary, since military teams might not be available to civilians during wartime. CRS Report RL31059(pdf) , Biological Weapons: A Primer , by [author name scrubbed]. CRS Report RS21288 , Smallpox: Technical Background on the Disease and Its Potential Role in Terrorism , by [author name scrubbed]. CRS Report RL31694 , Smallpox Vaccine Stockpile and Vaccination Policy , by [author name scrubbed]. CRS Report RL31793 , Vaccine Policy Issues for the 108th Congress , by [author name scrubbed]. CRS Report RL31475, First Responder Initiative: Policy Issues and Options , by Ben Canada. CRS Report RL31791, Emergency Management Funding for the Department of Homeland Security: Information and Issues for FY2004 , by [author name scrubbed], Coordinator, Rob Buschmann, Ben Canada,Wayne Morrissey, [author name scrubbed], and [author name scrubbed]. CRS Report RL31263 , Public Health Security and Bioterrorism Preparedness and Response Act ( P.L. 107-188 ): Provisions and Changes to Preexisting Law , by [author name scrubbed], DonnaU. Vogt, and Mary E. Tiemann. CRS Report RL31719 , An Overview of the U.S. Public Health System in the Context of Bioterrorism ,by [author name scrubbed]. CRS Report RL31853 , Food Safety Issues in the 108th Congress , by [author name scrubbed]. CRS Report RL31831 , Terrorist Motivations for Chemical and Biological Weapons Use: Placing the Threat in Context , by [author name scrubbed]. CRS Report RL30169, Export Administration Act of 1979 Reauthorization , coordinated by Ian F.Fergusson.

Summary: The anthrax mailings in 2001, which culminated in 5 deaths, 22 infections, and contamination of both postal and congressional buildings, intensified concerns about terrorist use of biologicalagents. This event increased Congressional interest in actions to limit the vulnerability of the UnitedStates to such attacks. High-threat biological agents, defined by the Centers for Disease Control andPrevention as Category A pathogens, are considered relatively easy to disseminate, have highmortality, and have the potential for major public health impacts. High-threat biological agents cause different symptoms in their victims, depending on the pathogen. Since the nature of these agents differs, no single treatment can be given in the case ofa biological attack. As a result, treatment of the victims of a biological attack, especially one whichis covert, may be difficult. The identification process for many pathogens may be complicated bytheir incubation period, and the lack of distinct symptoms early in the disease's progress. Thedifficulties in treating the various high-threat agents may place strain on the resources of the medicalsystem, especially in the case of mass casualties. Protection from biological agents is an area of active research and development. The range of protection and detection equipment available to first responders has led to questions regardingequipment standardization and state and local preparedness. Development and distribution ofvaccines continues to be a contentious issue. Attempts to detect biological releases using sensortechnologies, or through analyzing public health data, continue to be implemented, but thesetechnologies are in relatively early stages of development. It is unclear whether terrorist groups are capable of effectively using biological agents as weapons of mass destruction, but the relatively small amounts of pathogen that may be needed toexecute a significant attack is a source of concern. Some suggest that terrorist interest in biologicalagents is increasing. However, others assert that technical difficulties would make mass casualtyattacks unlikely. Current policies seek to reduce the proliferation of biological weapons by relying on both domestic and international controls, to increase the number of countermeasures available againstsuch pathogens through research and development activities, to improve the nation's ability to detectpathogen releases, and to increase the ability of hospitals and care providers to treat mass casualties. Policymakers may be called upon to further address potential biological terrorism vulnerabilities, including overseeing the use of atmospheric monitoring equipment for pathogendetection; the direction of continued research and development into biological agent detectors;review of further research into protective equipment, prophylaxis and treatment against high-threatpathogens; and assessment of first responder emergency preparedness. This report will be updatedas events warrant.