WBR1500

Author	PageAuthor::William J Gibson
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Microbiology
Sub Category	SubCategory::General Principles, SubCategory::Infectious Disease
Prompt	[[Prompt::A 35-year-old male presents to his primary care physician for muscular pain, sweating and fever over the past five days. He reports that his fever tends to increase throughout the day and falls at night. The patient denies any recent travel to foreign countries, or new sexual partners. He works as a goat farmer and hunts deer on the weekends. Physical exam is notable for cervical lymphadenopathy. If untreated, which of the following complications is most likely?]]
Answer A	AnswerA::Meningitis
Answer A Explanation	AnswerAExp::The waxing/waning fever in this patient heavily implicates Brucella infection. Meningitis has been reported as a very rare complication of brucellosis, but it is not considered a common feature of infection.
Answer B	AnswerB::Orchitis
Answer B Explanation	[[AnswerBExp::Orchitis is not associated with Brucella infection, but can be caused by Mumps, or STIs such as chlamydia and gonorrhea.]]
Answer C	AnswerC::Myocarditis
Answer C Explanation	AnswerCExp::Myocarditis is a common complication of another zoonotic infection, Lyme disease.
Answer D	AnswerD::Endocarditis
Answer D Explanation	[[AnswerDExp::Brucella infection is not commonly associated with endocarditis. Infection with other zoonotic organisms such as Bartonella can give rise to endocarditis. However, the most common cause of infective, native-valve endocarditis is Streptococcus viridans. More recent data suggest that Staphylococcus aureus may be accounting for an increasing share as well.]]
Answer E	AnswerE::Osteomyelitis
Answer E Explanation	[[AnswerEExp::Bone and joint complications are the most common focal complication of Brucella infection. Most cases of Brucella osteomyelitis affect the axial skeleton, with vertebral osteomyelitis occurring in 40% of these cases.]]
Right Answer	RightAnswer::E
Explanation	[[Explanation::The patient in this vignette has a classic case of undulating fever, caused by infection with Brucella species. Brucellosis is a highly contagious zoonotic infection that is most commonly associated with ingestion of unpasteurized dairy products or undercooked meat. Exposure to products from goats is especially associated with brucellosis. Educational Objective: Undulating fever is caused by infection with Brucella species. References: Colmenero JD, Ruiz-mesa JD, Plata A, et al. Clinical findings, therapeutic approach, and outcome of brucellar vertebral osteomyelitis. Clin Infect Dis. 2008;46(3):426-33. First Aid 2015 page 142 First Aid 2014 page 142]]
Approved	Approved::Yes
Keyword	WBRKeyword::Microbiology, WBRKeyword::Zoonotic, WBRKeyword::Bacteria, WBRKeyword::Fever, WBRKeyword::Brucella, WBRKeyword::Gram negative, WBRKeyword::Infection
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