_c._ Often the first indication of an attack with a biological agent will be the development of symptoms in exposed personnel. Diagnosis and treatment are complicated by the fact that many of the agent-induced diseases described in the guide begin with symptoms associated with common illnesses, such as influenza. In such cases, biological agent attacks may generally be distinguished from naturally occurring epidemics by the sudden onset of disease, the large number of personnel presenting with similar symptoms, and the concentration of those personnel in geographically contaminated areas.
_a._ Since a biological attack may produce mass casualties, preparations for a triage system should be in place before the attack. Paragraph 3.3.8 of the guide describes patient categories by illness severity. For a particular described operational scenario, this information may be used to estimate the number of patients with specified levels of illness. The guide does not provide estimates of the number of patients by triage classification or usual medical descriptions.
_b._ Decontamination of patients must be considered before further evacuation.
_a._ An efficient and flexible evacuation plan is essential for adequate casualty treatment and to retain mobility of forward medical resources. For an assessment of a potential mass casualty situation, the medical planner should consider the full range of evacuation assets, limitations, and obstacles. After an attack, the medical staff may need to estimate the number of casualties that could require evacuation at given postexposure times.
_b._ Evacuation requirements will vary with the type of biological agent used. Casualties resulting from some agents may not be evacuated because the time course of effects is relatively short. For others, like botulinum toxin, casualties may require evacuation to a facility where they can receive care for weeks or even months. Estimates provided in the guide can be used as a starting point from which to plan for evacuation resources, including those required for decontamination of personnel and transportation assets.
The casualty estimates in the guide are presented without allowance for in-unit care. However, there may be need for rapid intervention. Delays in obtaining medical care may occur because of physical damage or contamination of the surrounding area. Soldiers trained in first aid procedures may be the first to provide aid to biological agent casualties. The guide provides a conservative estimate of the numbers of exposed personnel who will require first aid. The tables described in paragraphs 3.3.2 through 3.3.4 of the guide give the time courses of effects that may apply to estimation of in-unit care and delayed medical requirements.