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{{WBRQuestion
{{WBRQuestion
|QuestionAuthor=William J Gibson
|QuestionAuthor=William J Gibson (Reviewed by  {{YD}})
|ExamType=USMLE Step 1
|ExamType=USMLE Step 1
|MainCategory=Microbiology
|MainCategory=Microbiology
Line 21: Line 21:
|MainCategory=Microbiology
|MainCategory=Microbiology
|SubCategory=General Principles, Infectious Disease
|SubCategory=General Principles, Infectious Disease
|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?
|Prompt=A 35-year-old man presents to his primary care physician for muscular pain, sweating, and fever over the past five days.  He reports that his fever tends to worsen throughout the day and breaks 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 remarkable for cervical lymphadenopathy and a body odor that resembles wet hay. If left untreated, development of which of the following complications is most likely?
|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.
|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 either unpasteurized dairy products or undercooked meat. Exposure to products from goats is especially associated with brucellosis. The classic triad of brucellosis includes undulating fever, sweating with a characteristic wet hay odor, and migratory arthralgia/myalgia. Bone and joint complications are the most common focal complication of ''[[Brucella]]'' infection.  The majority of cases of ''Brucella'' osteomyelitis affect the axial skeleton, with vertebral osteomyelitis occurring in approximately 40% of these cases.
|AnswerA=Meningitis
|AnswerA=Meningitis
|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.
|AnswerAExp=The waxing/waning fever in this patient is suggestive of ''Brucella'' infection. Meningitis has been reported as a very rare complication of brucellosis, but it is not considered a common feature of infection.
|AnswerB=Orchitis
|AnswerB=Orchitis
|AnswerBExp=Orchitis is not associated with ''[[Brucella]]'' infection, but can be caused by Mumps, or STIs such as chlamydia and gonorrhea.
|AnswerBExp=Orchitis is not associated with ''[[Brucella]]'' infection. It can be caused by mumps virus or STIs, such as ''Chlamydia'' and ''Gonorrhea''.
|AnswerC=Myocarditis
|AnswerC=Myocarditis
|AnswerCExp=Myocarditis is a common complication of another zoonotic infection, Lyme disease.
|AnswerCExp=[[Myocarditis]] is a common complication of Lyme disease, another zoonotic infection.
|AnswerD=Endocarditis
|AnswerD=Endocarditis
|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.
|AnswerDExp=''[[Brucella]]'' infection is not commonly associated with [[endocarditis]].  Infection with other zoonotic organisms, such as ''Bartonella'' spp. 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.
|AnswerE=Osteomyelitis
|AnswerE=Osteomyelitis
|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.
|AnswerEExp=Bone and joint complications are the most common focal complication of ''[[Brucella]]'' infection.  The majority of cases of ''Brucella'' osteomyelitis affect the axial skeleton, with vertebral osteomyelitis occurring in approximately 40% of these cases.
|EducationalObjectives=Undulating fever is caused by infection with Brucella species.
|EducationalObjectives=Undulating fever is caused by infection with Brucella species. Bone and joint complications are the most common focal complication of ''[[Brucella]]'' infection.  
|References=First Aid 2014 page 142
|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.<br>
 
First Aid 2015 page 142.
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.
|RightAnswer=E
|RightAnswer=E
|WBRKeyword=Microbiology, Zoonotic, Bacteria, Fever, Brucella, Gram negative
|WBRKeyword=Microbiology, Zoonotic, Bacteria, Undulating fever, Wet hay odor, Brucella, Gram negative, Infection, Brucellosis, Osteomyelitis, Complications
|Approved=Yes
|Approved=Yes
}}
}}

Latest revision as of 02:46, 28 October 2020

 
Author [[PageAuthor::William J Gibson (Reviewed by Yazan Daaboul, M.D.)]]
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Microbiology
Sub Category SubCategory::General Principles, SubCategory::Infectious Disease
Prompt [[Prompt::A 35-year-old man presents to his primary care physician for muscular pain, sweating, and fever over the past five days. He reports that his fever tends to worsen throughout the day and breaks 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 remarkable for cervical lymphadenopathy and a body odor that resembles wet hay. If left untreated, development of which of the following complications is most likely?]]
Answer A AnswerA::Meningitis
Answer A Explanation AnswerAExp::The waxing/waning fever in this patient is suggestive of ''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. It can be caused by mumps virus or STIs, such as Chlamydia and Gonorrhea.]]
Answer C AnswerC::Myocarditis
Answer C Explanation [[AnswerCExp::Myocarditis is a common complication of Lyme disease, another zoonotic infection.]]
Answer D AnswerD::Endocarditis
Answer D Explanation [[AnswerDExp::Brucella infection is not commonly associated with endocarditis. Infection with other zoonotic organisms, such as Bartonella spp. 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. The majority of cases of Brucella osteomyelitis affect the axial skeleton, with vertebral osteomyelitis occurring in approximately 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 either unpasteurized dairy products or undercooked meat. Exposure to products from goats is especially associated with brucellosis. The classic triad of brucellosis includes undulating fever, sweating with a characteristic wet hay odor, and migratory arthralgia/myalgia. Bone and joint complications are the most common focal complication of Brucella infection. The majority of cases of Brucella osteomyelitis affect the axial skeleton, with vertebral osteomyelitis occurring in approximately 40% of these cases.

Educational Objective: Undulating fever is caused by infection with Brucella species. Bone and joint complications are the most common focal complication of Brucella infection.
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.]]

Approved Approved::Yes
Keyword WBRKeyword::Microbiology, WBRKeyword::Zoonotic, WBRKeyword::Bacteria, WBRKeyword::Undulating fever, WBRKeyword::Wet hay odor, WBRKeyword::Brucella, WBRKeyword::Gram negative, WBRKeyword::Infection, WBRKeyword::Brucellosis, WBRKeyword::Osteomyelitis, WBRKeyword::Complications
Linked Question Linked::
Order in Linked Questions LinkedOrder::