The Windsor-Essex County Health Unit (WECHU) is investigating a probable case of tularemia related to the ingestion of locally hunted deer meat. Tularemia is a rare zoonotic disease caused by the bacteria Francisella tularensis. The bacteria is transmitted to humans through the bite of ticks or deer flies, handling infected animal tissues, ingesting contaminated food or water, or inhaling contaminated aerosols (e.g., through sorting contaminated hay or mowing). Person to person transmission has never been reported. Clinicians should consider tularemia in the differential diagnosis of patients with compatible signs and symptoms and exposure risk. This communication summarizes some important guidance related to the diagnosis and management of tularemia.
Clinical Presentation: Clinical presentation is typically sudden, with an abrupt onset of high fever, chills, fatigue, myalgia, nausea, and headache. The nature of the illness depends on how the bacteria enters the body. The main forms of the disease include:
- Ulcero-glandular - A skin ulcer appears at the entry site, with swelling of the regional lymph glands.
- Glandular - Swelling of the regional lymph glands, but without an ulcer.
- Oculoglandular- Irritation and inflammation of the eye and swelling of the lymph glands in front of the ear.
- Oropharyngeal - Sore mouth or throat (with or without ulcers), tonsillitis, and swelling of lymph glands in the neck.
- Pneumonic - Cough, chest pain, and difficulty breathing.
- Typhoidal - Any combination of general symptoms, without localizing signs and symptoms.
Risk Assessment: Assess the following to determine potential exposure risk:
- Consumption of raw/undercooked game meat
- Contact with wild rodents (e.g., squirrels) and lagomorphs (e.g., rabbits)
- Contact with infected animal tissue (e.g., hunting or skinning)
- Consumption of potentially contaminated water
- History of bites from ticks, flies, or mosquitoes
- Participation in farming or landscaping activities in which machinery (e.g., tractors, mowers) may run over infected animals or carcasses
Notification: As a disease of public health significance, clinicians are required to report all suspected and confirmed cases of tularemia to the health unit within one business day. Please fax notification to 226-783-2132.
Diagnosis and Management of Tularemia Cases
Laboratory Evidence: When testing, please ensure the following:
- Collect an appropriate clinical specimen, based on clinical presentation (e.g., blood, sputum, swab), and submit to a primary lab for Francisella tularensis culture, AND
- Collect whole blood or serum and submit to the Public Health Lab for Francisella tularensis serology.
- An acute (collected early after the onset of symptoms) and a convalescent (2-3 weeks post onset of symptoms) may be required for laboratory diagnosis.
- Public Health Ontario Laboratory is available for consultation on laboratory testing with health care providers as needed at (toll free) 1-877-604-4567.
Management: Isolation is not recommended for patients infected with tularemia, since there is no person-to-person transmission. Routine infection control practices should be used during patient care. Patients should be educated regarding the following preventive measures:
- Avoid bites of ticks, flies, and mosquitoes by:
- Using insect repellents that contains DEET
- Wearing long sleeves, long pants, and light coloured clothing
- Checking for ticks frequently
- Avoid contact with untreated water
- Cook game meat thoroughly
- Use impervious gloves when dressing game meat
If you have any questions or concerns, please call the Infectious Disease Prevention Department, Monday to Friday, between 8:30am and 4:30pm, at 519-258-2146, ext. 1420.
For more information:
- Centers for Disease Control and Prevention (CDC): Tularemia
- Ministry of Health Tularemia Case Definitions and Disease-Specific Information
- Public Health Ontario Laboratories: Francisella tularensis- Serology