Bioterrorism Agents And Barrier Protection

Francisella tularensis, Tularemia4 DEFINITION Tularemia is an acute infectious disease caused by Francisella tularensis. The organism is naturally occurring in a wide range of animal hosts, such as moles, mice, water rats, squirrels, rabbits, and hares, and can be recovered from contaminated water, soil, and vegetation. It requires inoculation, as inhalation of as few as ten organisms can cause disease. Tularemia occurs throughout much of North America, Europe, and Asia. It is transmitted to humans primarily through tick bites or handling infected animals. CLINICAL MANIFESTATIONS OF TULAREMIA4 Tularemia peaks with cases in rural areas in moderate climates such as in the Midwestern United States in summer, and again in winter during hunting seasons. F. tularensis could be used as a biological weapon in a number of ways, but the greatest concern would be focused on an aerosolized release that would cause pneumonic tularemia. Cases occurring in urban areas or in those with no risk factors should alert healthcare personnel to the possibility of a biological attack. Treatment of tularemia is critical to avoid progression to respiratory failure; meningitis; kidney, spleen, or liver involvement; sepsis; shock; and death. DIAGNOSIS There is no rapid diagnostic testing available for tularemia. Physicians who suspect tularemia should collect specimens of respiratory secretions and blood. F. tularensis may be identified through direct examination of secretions, exudates, or biopsy specimens using Gram stain, direct fluorescent antibody, or immunohistochemical stains. Growth of F. tularensis in culture is the definitive means of confirming the diagnosis. It can be grown from pharyngeal washings, sputum, and even gastric aspirates. Notify local health department. TREATMENT Supportive care for the patient. Administration of parenteral antibiotics. Mechanical ventilation support may be necessary. POST-EXPOSURE PROPHYLAXIS Post-exposure prophylaxis with antibiotics should be initiated following confirmed or suspected bioterrorism exposure, and for post-exposure management of healthcare workers and others who had unprotected face-to-face contact with symptomatic patients. There is a live attenuated vaccine commercially available for researchers with minimal adverse effects. There is no proven efficacy versus pneumonic tularemia. Clinical manifestations of Tularemia4 Tularemia Incubation Period Early Signs/Symptoms Later Signs/Symptoms Pneumonic tularemia 3-5 days, can range from 1-14 days. Abrupt onset fever, headache, chills, rigors, body aches, sore throat, dry cough, dyspnea, tachypnea, pleuritic pain, hemoptysis, nausea, vomiting diarrhea. Illness may be rapidly progressive and severe or may be indolent with progressive weakness and weight loss over several weeks to months. The progression of pneumonia tends to be slower than that of pneumonic plague. If untreated, can progress to respiratory failure, meningitis, sepsis, shock and death. INFECTION CONTROL Person-to-person transmission of tularemia has not been documented; therefore, Standard Precautions are considered adequate for patients with tularemia.10 Standard Precautions Handwashing Wash hands immediately after gloves are removed, between patient contacts, and when otherwise indicated to avoid transfer of microorganisms to other patients or environments. Gloves Wear gloves when touching blood, bodily fluid, secretions, excretions, and contaminated items; put on clean gloves just before touching mucous membranes and nonintact skin. Change gloves between tasks and procedures on the same patient after contact with material that may contain a high concentration of microorganisms. Remove gloves promptly after use, before touching noncontaminated items and environmental surfaces, and before going to another patient.Wash hands immediately to avoid transfer of microorganisms to other patients or environments. Masks, eye protection, face shields Wear a standard surgical mask and eye protection or a face shield to protect mucous membranes of the eyes, nose, and mouth during procedures and activities that are likely to generate splashes or sprays.

Previous Page | Table of Contents | Next Page