What are some other common infections that humans acquire from animals?

Case Study 3

From The Microbe Files:  Cases in Microbiology for the Undergraduate.  Cowan, Marjorie Kelly. pp 49-50, 61  Benjamin Cummings 2002

You work in a small family practice in rural Virginia.  A man in his early 50s comes in with a complaint of intermittent fever (102-103°F) and headache for the past two weeks.  The physician examines him and takes a history.  The only clinical finding is a wound about the size of a quarter on his right thumb.  Axillary lymph nodes are swollen and tender.  The man says he cut himself while skinning a rabbit three days ago.  On the basis of these observations the physician prescribes streptomycin and asks the man to call if his symptoms don’t improve in three days.

The physician asks you to draw blood and tells the patient he should return in four weeks for another blood sample.  She says there is no need to culture the wound.

1. On the basis of the limited information above, the physician has obviously made a diagnosis.  What is it?  What does it look like when Gram stained?
2. What is the most likely reservoir for the causative organism in this case?
3. Why draw blood twice?
4. Why not culture the wound for the bacterium?
5. What are some other common infections that humans acquire from animals? (These are also known as zoonoses).

The Usual Suspects

Common microorganisms causing infections in the cardiovascular system^1,2,3

Bacteria³

Gram-positive

Bacillus anthracis, Clostridium perfringens, Streptococcus pyogenes, Other streptococci

Gram-negative

Bartonella henselae, Borrelia burgdorferi, Brucella species, Ehrlichia species, Francisella tularensis, Rickettsia species, Yersinia pestis

Fungi

Various

Viruses

Coxsackievirus, Dengue fever virus, Ebola virus, Epstein-Barr virus, Yellow fever virus, Human immunodeficiency virus

Protozoa

Babesia microti, Plasmodium species, Schistosoma species, Trypanosoma cruzi, Wucheria bancrofti

¹Not all of the infections appear in this chapter.

²Not an exhaustive list.

³Many bacteria can cause bloodstream infections if given access; this table lists those adapted to cause disease in this system.