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Difficulty: MediumInfectious Diseases

Match each clinical presentation of a zoonotic or vector-borne infectious disease with the most appropriate targeted antimicrobial therapy.

  • A 30-year-old man from the Northeast United States presents with fever and dark urine; laboratory testing reveals hemolytic anemia, thrombocytopenia, and intraerythrocytic tetrads on a peripheral blood smear.Atovaquone and azithromycin
  • A 25-year-old woman presents with a tender, enlarged axillary lymph node; she reports adopting a kitten a few weeks ago and has a healing scratch on her ipsilateral hand.Azithromycin
  • A 35-year-old man recently returned from rural South America presents with fever and unilateral painless periorbital edema; blood microscopy reveals motile trypomastigotes.Benznidazole
  • A 40-year-old man presents with an ulcerated skin lesion with a dark eschar on his hand and painful regional lymphadenopathy; he recently hunted and skinned a wild rabbit.Streptomycin
  • A 42-year-old farmer presents with high fever, severe headache, and a nonproductive cough after assisting with sheep parturition; testing shows elevated transaminases and interstitial pneumonia.Doxycycline

Answer

The correct matches align specific zoonotic and vector-borne clinical syndromes with their definitive antimicrobial therapies: Babesiosis is treated with atovaquone and azithromycin; cat scratch disease with azithromycin; Chagas disease with benznidazole; tularemia with streptomycin; and Q fever with doxycycline.
Each pathogen requires a specific class of antimicrobial based on its unique biology: Babesia (protozoan) requires atovaquone/azithromycin; Bartonella (fastidious bacteria) responds to azithromycin; Trypanosoma (parasite) requires benznidazole; Francisella (Gram-negative coccobacillus) is best treated with aminoglycosides; and Coxiella (intracellular bacteria) requires tetracyclines.

Step-by-Step Solution

1
Identify the etiology for each distinct clinical vignette based on exposure history and physical or laboratory findings.
The vignettes describe Babesiosis, cat scratch disease, Chagas disease, tularemia, and Q fever, respectively.
Accurate pathogen identification is the prerequisite for selecting targeted antimicrobial therapy.
2
Determine the therapy for Babesiosis (hemolytic anemia, intraerythrocytic tetrads).
Match with atovaquone and azithromycin.
This combination effectively targets the intraerythrocytic protozoa while minimizing toxicity.
3
Determine the therapy for cat scratch disease (kitten exposure, regional lymphadenitis).
Match with azithromycin.
A short course of azithromycin accelerates the resolution of Bartonella henselae lymphadenopathy.
4
Determine the therapy for acute Chagas disease (South American travel, Romaña sign).
Match with benznidazole.
Benznidazole (or nifurtimox) is the required therapy for acute Trypanosoma cruzi infection.
5
Determine the therapy for tularemia (rabbit exposure, ulceroglandular disease).
Match with streptomycin.
Aminoglycosides are the gold standard for severe or ulceroglandular Francisella tularensis infection.
6
Determine the therapy for acute Q fever (livestock exposure, atypical pneumonia/hepatitis).
Match with doxycycline.
Doxycycline effectively clears the intracellular pathogen Coxiella burnetii.

Key Concept

Targeted antimicrobial therapy for zoonotic and vector-borne infectious diseases must be selected based on distinct epidemiological exposures and classic clinical manifestations.
Estimated Time:1m 30s
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Topics

Infectious Diseases

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