rodent and rabbit assay data sheet

Tularemia (Francisella tularensis)

Test code: B0058 - Ultrasensitive screen for Francisella tularensis by real time polymerase chain reaction.

Francisella tularensis is a small Gram-negative aerobic bacillus with two main serotypes: Jellison Type A and Type B. Type A is the more virulent form. Tularemia is frequently spread by direct contact with rabbits, leading to the term "rabbit fever." The disease can also be spread by rodents, and by ticks.

F. tularensis is very resistant to environmental changes and is capable of surviving for weeks at low temperatures in water, moist soil, hay, straw, or decaying animal carcasses. Small mammals such as voles, mice, water rats, squirrels, rabbits, and hares are natural reservoirs for F. tularensis. These animals are infected with the bacteria through bites from ticks, fleas, and mosquitoes and contact with contaminated environments. People are infected through bites from infected arthropods (usually ticks), contact with infected animal tissues or fluids, direct contact with or ingestion of contaminated water, food, or soil, or inhalation of aerosolized bacteria. F. tularensis is very infectious so that the simple act of examining an open laboratory culture plate without adequate protective equipment can lead to infection and disease. For this reason, F. tularensis is classified as a bioterrorism agent and culture of the bacteria without suitable laboratory facilities is not recommended.

People infected with the bacteria can develop symptoms in 3 to 5 days but some people may take as long as two weeks for symptoms to develop. Symptoms vary with mode of infection, but generally include fever, chills, joint and muscle pain, headache, weakness and sometimes pneumonia. People who develop pneumonic tularemia experience chest pain, bloody sputum and difficulty breathing. The disease is easily cured by antibiotic treatment.

Culture detection of the bacteria is usually not suitable due to the highly infectious nature of the bacteria. Culture is also not very sensitive (Johansson et al., 2000). Serological diagnosis can be unreliable because some infections may not result in seroconversion (Johansson et al., 2000). Molecular detection of F. tularensis is rapid, sensitive and specific.

Utilities:

• Confirm the disease causing agent
• Shorten the time required to confirm a clinical diagnosis of Tularemia infection
• Ensure that animal populations are free of Tularemia
• Early prevention of the spread of Tularemia
• Minimize human exposure to Tularemia
• Safety monitoring of biological products and vaccines that derive from susceptible animals

References:
Johansson, A., Berglund, L., Eriksson, U., Göransson, I., Wollin, R., Forsman, M., Tärnvik, A. and Sjöstedt, A. (2000) Comparative Analysis of PCR versus Culture for Diagnosis of Ulceroglandular Tularemia. J. Clin. Microbiol. 38: 22-26.

Specimen requirement: 0.2 ml whole blood in EDTA (purple top) or ACD (yellow top) tube.

For specimen types other than those listed here, please call to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Qualitative real time PCR

Normal range: Nondetected