Clinical recognition and management of patients exposed to biological warfare agents.

Concern regarding the use of biological agents (bacteria, viruses, or toxins) as tools of warfare or terrorism has led to measures to deter their use or, failing that, to deal with the consequences. Unlike chemical agents, which typically lead to severe disease syndromes within minutes at the site of exposure, diseases resulting from biological agents have incubation periods of days. Rather than a paramedic, it will likely be a physician who is first faced with evidence of the results of a biological attack. Provided here is an updated primer on 11 classic BW and potential terrorist agents to increase the likelihood of their being considered in a differential diagnosis. Although the resultant diseases are rarely seen in many countries today, accepted diagnostic and epidemiologic principles apply; if the cause is identified quickly, appropriate therapy can be initiated and the impact of a terrorist attack greatly reduced.

Biological weapons--a primer for microbiologists.

Biological weapons are not new. Biological agents have been used as instruments of warfare and terror for thousands of years to produce fear and harm in humans, animals, and plants. Because they are invisible, silent, odorless, and tasteless, biological agents may be used as an ultimate weapon-easy to disperse and inexpensive to produce. Individuals in a laboratory or research environment can be protected against potentially hazardous biological agents by using engineering controls, good laboratory and microbiological techniques, personal protective equipment, decontamination procedures, and common sense. In the field or during a response to an incident, only personal protective measures, equipment, and decontamination procedures may be available. In either scenario, an immediate evaluation of the situation is foremost, applying risk management procedures to control the risks affecting health, safety, and the environment. The microbiologist and biological safety professional can provide a practical assessment of the biological weapons incident to responsible officials in order to help address microbiological and safety issues, minimize fear and concerns of those responding to the incident, and help manage individuals potentially exposed to a threat agent.

Bioterrorism.

Although biological agents have been used in warfare for centuries, several events in the past decade have raised concerns that they could be used for terrorism. Revelations about the sophisticated biological-weapons programs of the former Soviet Union and Iraq have heightened concern that countries with offensive-research programs, including those that sponsor international terrorism, might assist in the proliferation of agents, culturing capability, and dissemination techniques, and might benefit in these undertakings from the availability of skilled laboratory technicians. Release of sarin nerve agent in the Tokyo subway system in 1995 by the Aum Shinrikyo cult demonstrated that in the future terrorists might select unconventional weapons. Certain properties of biological pathogens may make them the ideal terrorist weapon, including 1) ease of procurement, 2) simplicity of production in large quantities at minimal expense, 3) ease of dissemination with low technology, and 4) potential to overwhelm the medical system with large numbers of casualties. Dissemination of a biological agent would be silent, and the incubation period allows a perpetrator to escape to great distances from the area of release before the first ill persons seek medical care. Countermeasures include intelligence gathering, physical protection, and detection systems. Medical countermeasures include laboratory diagnostics, vaccines, and medications for prophylaxis and treatment. Public health, medical, and environmental health personnel need to have a heightened awareness, through education, about the threat from biological agents.

Bioterrorism: agents of concern.

The intentional dispersal of biological agents by terrorists is a potential problem that increasingly concerns the intelligence, law enforcement, medical, and public health communities. Terrorists might choose biological agents over conventional and chemical weapons for multiple reasons, although it is difficult to predict, with certainty, which biological agents might prove attractive to terrorists. One can more confidently, however, derive a list of those few agents which, if used, would be of greatest public health consequence. It is these agents which will require the most robust countermeasures. We discuss the derivation of this short list of agents and the specific diseases involved.

A field-expedient algorithmic approach to the clinical management of chemical and biological casualties.

Warriors on the modern battlefield face considerable danger from possible attack with chemical and biological weapons. Aggravating this danger is the fact that medical resources at the lowest echelons of care, already likely to be strained to capacity during modern conventional combat, are at present inadequate to handle large numbers of chemical or biological casualties. Complicating this problem further is the austere nature of diagnostic modalities available at lower echelons. With this in mind, and given the urgency required to adequately manage chemical and biological casualties, it is likely that such casualties will initially require significant empiric care in the absence of a definitive diagnosis. Such care under field conditions, often rendered by relatively inexperienced medical personnel, might best be provided using an algorithmic approach. We have developed such an algorithm.

Immunization against potential biological warfare agents.

The intentional release of biological agents by belligerents or terrorists is a possibility that has recently attracted increased attention. Law enforcement agencies, military planners, public health officials, and clinicians are gaining an increasing awareness of this potential threat. From a military perspective, an important component of the protective pre-exposure armamentarium against this threat is immunization. In addition, certain vaccines are an accepted component of postexposure prophylaxis against potential bioterrorist threat agents. These vaccines might, therefore, be used to respond to a terrorist attack against civilians. We review the development of vaccines against 10 of the most credible biological threats.

Air evacuation under high-level biosafety containment: the aeromedical isolation team.

Military contingency operations in tropical environments and potential use of biological weapons by adversaries may place troops at risk for potentially lethal contagious infections (e.g., viral hemorrhagic fevers, plague, and zoonotic poxvirus infections). Diagnosis and treatment of such infections would be expedited by evacuating a limited number of patients to a facility with containment laboratories. To safely evacuate such patients by military aircraft and minimize the risk for transmission to air crews, caregivers, and civilians, the U.S. Army Medical Research Institute of Infectious Diseases maintains an aeromedical isolation team. This rapid response team, which has worldwide airlift capability designed to evacuate and manage patients under high-level containment, also offers a portable containment laboratory, limited environmental decontamination, and specialized consultative expertise. This article also examines technical aspects of the team's equipment, training, capabilities, and deployments.

Cutaneous manifestations of biological warfare and related threat agents.

The specter of biological warfare (BW) looms large in the minds of many Americans. The US government has required that emergency response teams in more than 100 American cities be trained by the year 2001 to recognize and contain a BW attack. The US military is requiring active duty soldiers to receive immunization against anthrax. Dermatologists need not feel helpless in the face of a potential BW attack. Many potential agents have cutaneous manifestations that the trained eye of a dermatologist can recognize. Through early recognition of a BW attack, dermatologists can aid public health authorities in diagnosing the cause so that preventive and containment measures can be instituted to mitigate morbidity and mortality. This article reviews bacterial, viral, and toxin threat agents and emphasizes those that would have cutaneous manifestations following an aerosol attack. We conclude with clues that can help one recognize a biological attack.

Anthrax as a potential biological warfare agent.

Anthrax is a zoonotic illness recognized since antiquity. Today, human anthrax has been all but eradicated from the industrialized world, with the vast majority of practitioners in the United States unlikely to have seen a case. Unfortunately, the disease remains endemic in many areas of the world, and anthrax poses a threat as a mass casualty-producing weapon if used in a biological warfare capacity.

Clinical recognition and management of patients exposed to biological warfare agents.

Concern regarding the use of biological agents--bacteria, viruses, or toxins--as tools of warfare or terrorism has led to measures to deter their use or, failing that, to deal with the consequences. Unlike chemical agents, which typically lead to violent disease syndromes within minutes at the site of exposure, diseases resulting from biological agents have incubation periods of days. Therefore, rather than a paramedic, it will likely be a physician who is first faced with evidence of the results of a biological attack. We provide here a primer on 10 classic biological warfare agents to increase the likelihood of their being considered in a differential diagnosis. Although the resultant diseases are rarely seen in many countries today, accepted diagnostic and epidemiologic principles apply; if the cause is identified quickly, appropriate therapy can be initiated and the impact of a terrorist attack greatly reduced.

Biological warfare. A historical perspective.

The deliberate use of microorganisms and toxins as weapons has been attempted throughout history. Biological warfare has evolved from the crude use of cadavers to contaminate water supplies to the development of specialized munitions for battlefield and covert use. The modern development of biological agents as weapons has paralleled advances in basic and applied microbiology. These include the identification of virulent pathogens suitable for aerosol delivery and industrial-scale fermentation processes to produce large quantities of pathogens and toxins. The history of biological warfare is difficult to assess because of a number of confounding factors. These include difficulties in verification of alleged or attempted biological attacks, the use of allegations of biological attacks for propaganda purposes, the paucity of pertinent microbiological or epidemiologic data, and the incidence of naturally occurring endemic or epidemic diseases during hostilities. Biological warfare has been renounced by 140 nations, primarily for strategic and other pragmatic reasons. International diplomatic efforts, including the 1972 Biological Weapons Convention, have not been entirely effective in preventing the enhancement and proliferation of offensive biological warfare programs. The threats posed by biological weapons are likely to continue into the future.

Acute pseudophakic pupillary block glaucoma.

Intraocular lenses are becoming increasingly common, yet many emergency physicians are unaware of their potential complications. The case of a 59-year-old man whose anterior chamber lens occluded the pupil, resulting in acute glaucoma with an intraocular pressure exceeding 65 mm Hg, is presented. He was treated successfully with medical therapy and laser iridotomy. A review of this condition, treatment, and prognosis is presented. The emergency treatment of pupillary block glaucoma differs from that of "classic" acute closed-angle glaucoma.

Aortoenteric fistula: a catastrophe waiting to happen.

Presented is the case of a patient with recurrent massive upper gastrointestinal hemorrhage. Evaluation during initial hospitalization revealed no definite etiology. During his second hospitalization, he underwent exploratory laparotomy, and an abdominal aortic aneurysm with fistulization into the duodenum was identified. During surgery the patient suffered a cardiopulmonary arrest and could not be resuscitated. This case exemplifies some of the important clinical features that may suggest the diagnosis, including presence of a pulsatile abdominal mass, a peculiarly intermittent or obscure source of bleeding, and the concomitant complaint of back pain and gastrointestinal bleeding.

Invasive aspergillosis of the hand.

Aspergillosis is a fungal infection which may disseminate from the lung to bone, meninges, heart, or other organs. It is commonly found in patients with debilitating disease and those undergoing chemotherapy. A 6-year-old boy, seen at Fitzsimons Army Medical Center while being treated for acute monomyelocytic leukemia, developed invasive aspergillosis of the hand, requiring resection of the central three rays. This rare presentation of the disease required radical surgery to control its local manifestations and to prevent widespread dissemination.