Download the Case Study

Presentation

A 50-year-old male presents to the physician with swollen lymph nodes in the groin area (inguinal lymphadenopathy). The patient is married and lives in rural Kentucky, and is an ordained minister. Both the patient and his wife claim they are in a monogamous relationship. The patient handled a sick, wild baby rabbit one week prior to the onset of symptoms. A tissue specimen was submitted to a reference laboratory for bacterial, Chlamydia-specific, fungal and mycobacterial cultures and a biopsy was submitted for pathology.   

Lab Testing

No growth was observed on the Chlamydia culture. However, the specimen was not submitted in the proper transport medium so Chlamydia could not be ruled out. The bacterial culture showed a small, Gram-negative rod that grew on chocolate agar. The reference laboratory used pyrosequencing and obtained a result of Francisella tularensis. Francisella tularensis is a select agent declared by the U.S. Department of Health and Human Services or U.S. Department of Agriculture to have the "potential to pose a severe threat to public health and safety". The work up on the organism was stopped and the isolate was sent to the public health laboratory for molecular testing and confirmation. The lymph node biopsy revealed a granulomatous abscess consistent with lymphogranuloma venereum (LGV) or a long-term infection of the lymphatic system.

Cause of Symptoms

Francisella tularensis is a Gram-negative rod and is the causative agent of Rabbit Fever, Deer Fly Fever and Men’s Market Disease. Francisella tularensis (Tularemia) is associated with a history of animal or tick exposure, and is often seen in hunters. The incubation period can range from 1-21 days and symptoms typically consist of an abrupt onset of fever, chills, malaise, anorexia and fatigue. Common animals that can harbor F. tularensis are rabbits, muskrats, beavers, squirrels and birds. The organism can also be spread by drinking contaminated water or breathing in contaminated dust. If untreated, death can occur but deaths due to Tularemia have decreased significantly since the advent of antibiotics.  
 
There are 6 classical forms:

• Ulceroglandular,
• Glandular,
• Oculoglandular,
• Pharyngeal,
• Typhoidal, and
• Pneumonic.

Treatment

Patient was treated with and responded well to doxycycline. While the treatment of choice is an aminoglycoside such as gentamicin, doxycycline is an acceptable treatment for Tularemia.