Tularemia

Causative Agent

Francisella tularensis

Type of Organism

Bacterial Species

Length of Attachment for Transmission

Unknown

Initial Symptoms

• Symptoms can range from mild to life threatening.
• There are many ways Tularemia can present in an infected person. All forms of this disease will include a high fever.
• An ulceroglandular infection characterized by a skin ulcer at the site of tick attachment and swelling of lymph nodes near the site of attachment may occur.
• A glandular infection is also possible which involves swelling of the lymph nodes closest to the site of tick attachment but without the skin ulcer.

Diagnosis and Testing

Skin biopsy or secretion can be visualized under a microscope using a gram stain or fluorescently labelled antibodies to identify the presence of Francisella tularensis.

CDC Treatment Recommendation

• Adults: Streptomycin, 1g IM- 2x daily; Gentamicin, 5 mg/kg IM or IV once a day
• Children: Streptomycin, 15 mg/kg IM-2x daily; Gentamicin, 2.5 mg/kg IM or IV- 3x daily

Disease Pathogenesis

Ulceroglandular Infection

Once in the host, Francisella tularensis will replicate at the site of infection causing inflammation where the tick bite occurred. The inflammation will eventually lead to the formation of an ulcer.

The bacteria will then migrate to local lymph nodes causing inflammation.

Glandular Infection

Once in the host, Francisella tularensis will move to the lymph nodes without causing inflammation at the tick bite location.