Disclaimer: Biological agents can cause disease processes with overlapping clinical syndromes that result in uncertainty in the early stages of disease presentation. This appendix provides potentially diagnostic clinical clues (PDCCs or PDCs) in an algorithmic format to help narrow the differential diagnosis when epidemiologic clues are not present, and when specific laboratory diagnostic tests (e.g., PCR) are pending or unavailable. PDCCs are defined as localizing signs, symptoms, and abnormalities potentially pointing toward a possible diagnosis.1 Traditional biothreats and other common endemic diseases have been included where possible; however, the potential use of biological weapons presents a diagnostic dilemma as discussed in the main text of the CPG. The algorithms in this appendix are geographically and Service agnostic and can serve as a template for units to adapt to create their own versions for a specific operating environment.

The information provided in this appendix is not meant to substitute for the independent clinical judgment of a physician, relative to diagnostic or treatment options for a specific patient’s medical condition. It is designed to provide information and assist decision making. It is not intended to define a standard of care and should not be construed as one; neither should it be interpreted as prescribing an exclusive course of management. This appendix was developed by experts in this field. Variations in practice will inevitably and appropriately occur when clinicians consider the needs of individual patients, available resources, and limitations unique to an institution or type of practice. Every healthcare professional making use of this appendix is responsible for evaluating the appropriateness of applying it in the setting of any clinical situation. This appendix does not supersede any DoD policy.

The algorithms included in this appendix are as follows:

Algorithm 1 – Undifferentiated Fever

Algorithm 2 – Neurologic (Headache, Photophobia, Neck Stiffness, Altered Mental Status, Weakness)

Algorithm 3 – Respiratory (Fever, Cough, Congestion, Rhinorrhea, Wheezing, Shortness of Breath)

Algorithm 4 – Gastrointestinal (Abdominal Pain, Nausea, Vomiting, Diarrhea)

Algorithm 5 – Cutaneous or Lymphadenopathy (Rashes, Wounds, Skin Lesions)

Algorithm 6 – Viral Hemorrhagic Fever: (Petechiae, Subconjunctival Hemorrhage, Mucosal Bleeding)