Page 87 - Journal of Special Operations Medicine - Winter 2016

An Ongoing Series

Tularemia

Mark W. Burnett, MD

Introduction Diagnosis
Tularemia is a disease of varied presentations that causes Organisms can remain present in the blood for up to 2
illness primarily in animals, but it can also infect those weeks after the onset of infection and in skin tissue for
who spend time outdoors and is a known threat as a bio- up to 1 month if the patient is not properly treated. Al-
terrorism agent. Caused by the gram-negative pleomor- though this infection cannot be transmitted from person
phic coccobacillus Francisella tularensis, infections have to person, it can be readily transmitted in a laboratory
been reported across most of the temperate areas of the setting, so personnel should be alerted if a tularemia
northern hemisphere, as well as in Australia. In the United infection is suspected. Isolation of organisms from the
States, cases have been seen in all states except Hawaii. blood, skin, and ulcerative drainage can be achieved by
using specialized media. Gram stains, polymerase chain
reaction, and fluorescent antibody testing of the same
Clinical Presentation
sources of material have also been used in making the
Primarily a disease of rabbits and hares, prairie dogs, diagnosis of tularemia. The most common method of di-
as well as smaller rodents, infections can be passed to agnosis, however, is through the use of paired serologic
humans and manifest in a variety of ways through direct tests showing a fourfold or greater titer change between
contact with an infected animal, drinking contaminated paired samples drawn at least 2 weeks apart after the
water, or by the bite of an infected tick or deer fly. Hu- second week of the illness. Infections with F. tularensis
man infections are characterized by an acute onset of are challenging diagnoses to make and should be made
fevers, chills, headache, cough, and muscle aches. The in conjunction with an infectious disease specialist or the
most common type of presentation is the ulceroglandu- Centers for Disease Control and Prevention (Figure 1).
lar syndrome, in which a painful papule develops at the
site of inoculation concurrent with the onset of fever. Treatment
The papule will develop into a pustule and then will ul-
cerate into a lesion with “heaped-up edges,” which is The treatment of choice is streptomycin (1g intramus-
often associated with proximate painful lymph nodes. cularly [IM] twice daily) or gentamicin (5mg/kg IM or
Other less common types of illness are the glandular
syndrome (lymphadenopathy without ulceration), ocu- Figure 1 Thumb with skin ulcer of tularemia.
loglandular syndrome (conjunctivitis and preauricular
lymphadenopathy), and typhoidal tularemia, which is a
nonspecific febrile illness with headache, muscle aches,
vomiting, diarrhea, and abdominal pain. Respiratory
tularemia with its fever, nonproductive cough, chest
pain, difficulty breathing, and hilar adenopathy on chest
radiograph is seen in those infected by aerosolized dust
contaminated with the organism in farming activities or
lawn mowing but is also the expected type of presenta-
tion if tularemia were to be used as a biowarfare agent.

Clinical Description

This illness is characterized by several distinct forms, as Source: Centers for Disease Control and Prevention / Emory Univer-
shown in Table 1. sity, Dr Sellers, 1964.

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