Tularemia: Francisella tularensis

Question 1

Classify Francisella tularensis

Answer 1

Gram negative

Aerobic

Non-motile

Non-spore forming

Coccobacillus

Question 2

What is tularemia also known as?

Answer 2

Rabbit fever

–frequently spread by rabbits, but also by rodents and arthropods (ticks) and deer flies

Question 3

How is tularemia transmitted?

Answer 3

Animal vectors (rabbits, rodents, arthorpods [ticks], flies)
--undercooked meat is a possible route

Contaminated water

Inhalation of dust

***NOT transmitted from person-person

Question 4

Is tularemia a potential bioterror weapon?

Answer 4

Yes. It can be aerosolized.

Question 5

How is tularemia virulent?

Try to describe how it is virulent.

Answer 5

Basically, it can survive attack from the innate immune system.

• -It’s LPS has less of an immunostimulatory role
• -It’s capsule gives it complement resistance
• -iglABCD operon allows survival in macrophages via transposon mutagenesis

Question 6

How long does it take exposed people to become sick from tularemia?

Answer 6

Generally from 2-10 days, but incubation can vary from hours –> weeks.

Question 7

What are the 6 disease presentations of tularemia?

Answer 7

1) Ulceroglandular (most common)
2) Glandular
3) Oculoglandular
4) Oropharyngeal
5) Pneumonic
6) Typhoidal (rare)

Question 8

Which tularemia disease is this:

• eye pain
• eye redness
• eye swelling + discharge
• ulcer on the inside of the eyelid

Answer 8

Oculoglandular tularemia

–rubbing your eyes after handling a dirty animal is how you get this

Question 9

Which tularemia disease is this:

• Fever
• Sore throat
• Vomiting
• Diarrhea
• –These are all seen after eating poorly cooked wild animal meat or drinking contaminated water

Answer 9

Oropharyngeal tularemia

• -this form affects the digestive tract
• -heat kills tularemia so need to not eat raw meat

Question 10

Which tularemia disease is this:

• skin ulcer (insect or animal bite infection)
• swollen + painful lymph glands
• fever
• chills
• headache
• exhaustion

Answer 10

Ulceroglandular tularemia

• -this is the most common form of tularemia
• -animal/insect bite or handling diseased animal most common way in getting this.

Question 11

Which tularemia disease is this:

• swollen + painful lymph glands
• fever
• chills
• headache
• exhaustion

Answer 11

Glandular tularemia

–note the lack of a skin ulcer in the presentation. Otherwise, same as ulceroglandular tularemia.

Question 12

Which tularemia disease is this:

• cough
• chest pain
• difficulty breathing
• -most common in the elderly

Answer 12

Pneumonic tularemia

• -inhaling the bacteria that’s become airborne after gardening, construction, etc
• -note that other forms of tularemia can spread to the lungs

Question 13

Which tularemia disease is this:

• High fever
• extreme exhaustion
• Vomiting, diarrhea
• splenomegaly
• hepatomegaly
• pneumonia

Answer 13

Typhoidal tularemia

–rare and most severe form

Question 14

How do you diagnose tularemia?

Answer 14

1) Blood culture/gram stain
2) Serology (measure immune response)
3) CXR (patchy infiltrates)
4) PCR an ulcer sample

Question 15

How can you tell a normal outbreak vs. Bioterror event?

Answer 15

1) Bioterror outbreak has a point-source (urban, non-agricultural city)
2) Lots of respiratory illness in healthy people

Question 16

Describe the pathology of tularemia?

Answer 16

Acute suppurative necrosis followed by granulomatous reactions, especially in the lungs, lymph nodes, spleen, liver, and kidney

Question 17

How do you treat tularemia?

Answer 17

Streptomycin + tetracycline

Gentamycin works as alternative to streptomycin

Question 18

Compare and contrast anthrax, plague, and tularemia on their COUGH/SPUTUM and CXR:

Answer 18

Anthrax: dry, non-productive cough + widened mediastinum on CXR

Plague: productive, watery to bloody cough + acute bacterial pneumonia signs on CXR

Tularemia: non-productive cough + patch infiltrates on CXR