Baylor University Medical Center Proceedings April 2017 - 175

Tularemia presenting as pulmonary nodules
in an immunocompromised patient
Tony Alias, MD, Mohammad Kazem Fallahzadeh, MD, and Mezgebe Berhe, MD, MPH

Tularemia is a zoonotic disease caused by Francisella tularensis that
can be transmitted to humans when they handle rabbits, receive tick
bites, consume contaminated water, or inhale aerosolized particles.
We present the case of a 51-year-old white man with rheumatoid
arthritis who was taking immunosuppressive medications and presented with tularemia. Our patient acquired the typhoidal form of
tularemia, which is a severe systemic illness that manifests with
fevers, headaches, myalgias, vomiting, diarrhea, and neurological
symptoms, due to his immunocompromised state. The diagnosis was
made through biopsy of a pulmonary nodule found incidentally on
computed tomography scan.

CASE PRESENTATION
A 51-year-old white man with rheumatoid arthritis and
Addison's disease came in to the emergency department complaining of generalized weakness, watery diarrhea, fever, and
chest pain for 3 days. On the day of admission, he was confused
and lethargic. His medications included a monthly inﬂiximab infusion, leﬂunomide 5 mg orally two times daily for
rheumatoid arthritis, and ﬂudrocortisone 0.1 mg orally once
daily for Addison's disease. He lived with his wife, children,
and a dog on a ranch in Wichita Falls, Texas. At admission,
his blood pressure was 130/70 mm Hg; heart rate, 103 beats
per minute; and temperature, 101.9°F. Physical examination
was unremarkable. His white blood cell count was 6100/μL
and platelet count, 80,000/μL. Computed tomography (CT)
showed multiple pulmonary parenchymal nodules bilaterally with mediastinal adenopathy and a right pleural eﬀusion
(Figure).
He was started on intravenous vancomycin, cefepime,
and metronidazole. On day 3, one of the pulmonary nodules
was biopsied. Bactrim 80 to 160 mg/day was added on day 4,
and he was discharged. One week later, he was informed by
the state health department that the lung biopsy culture grew
Francisella tularensis. He was then readmitted for intravenous
infusion of gentamicin and oral ciproﬂoxacin. Further history
revealed that he had found dead cottontail rabbits in his backyard several weeks earlier and had picked them up with his bare
hands. Thereafter, he may have inhaled the aerosolized organism from mowing the lawn. His dog became sick after this and
Proc (Bayl Univ Med Cent) 2017;30(2):175-176

developed supraclavicular lymphadenitis that required incision
and drainage along with intravenous antibiotics. He was treated
with 3 weeks of intravenous gentamicin and oral ciproﬂoxacin.
A repeat CT of the chest showed that the pulmonary nodules
had decreased in size.
DISCUSSION
Tularemia is a zoonotic infection that is endemic in North
America, continental Europe, Russia, Japan, and China. In
1911, McCoy and Chapin ﬁrst isolated a gram-negative bacterium from ground squirrels suﬀering from a plague-like disease
in Tulare County, California, and named it Bacterium tularense
(1). The ﬁrst documented case of human infection was in 1914,
when this bacterium was isolated from a meat cutter who developed conjunctivitis and lymphadenopathy (2). Edward Francis
reviewed about 800 cases of infections with this bacterium and
published a paper describing the clinical characteristics of the
disease in 1928 (3); the bacterium was renamed Francisella
tularensis after him.
F. tularensis is gram-negative coccobacilli that can be contracted through an arthropod bite, the handling of an infected
animal carcass, or the consumption of contaminated water and
meat. Small rodents and lagomorphs (hares and rabbits) are the
most common animal reservoirs. From 2005 to 2014, 95 to 203
cases of tularemia were reported per year in the United States
(4). This condition is most prevalent in the Southwest region
of the United States, including Arkansas, Kansas, Louisiana,
Missouri, Oklahoma, and Texas. Men have contracted more
than 70% of cases of tularemia, possibly due to exposure from
hunting and landscaping (4).
Of the six described forms of tularemia, ulceroglandular
tularemia is most common and is acquired through an infected
skin lesion that leads to lymphadenopathy (5). This patient
was diagnosed with the typhoidal form of tularemia, which
usually presents with acute-onset fevers, headaches, myalgias,
vomiting, diarrhea, and neurological symptoms including
From the Departments of Radiology (Alias), Internal Medicine (Fallahzadeh), and
Infectious Diseases (Berhe), Baylor University Medical Center at Dallas, Texas.
Corresponding author: Tony Alias, MD, Department of Radiology, Baylor
University Medical Center at Dallas, 3500 Gaston Avenue, Dallas, TX 75246
(e-mail: tony.alias1@bswhealth.org).
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