APIM223887223 - CME/CMLE - Bacteremia / Septicemia with Rare or Atypical Organisms-APIM223887223

APIM223887223 - Educational Activity

Pdf Summary

The educational commentary by Lauren Roberts from Tarleton State University discusses the diagnostic challenges associated with bacteremia caused by rare or atypical organisms, specifically focusing on Rat-bite Fever (RBF). RBF is a zoonotic infection predominantly caused by *Streptobacillus moniliformis* in North America and *Spirillum minus* in Asia. The infection often follows a bite or scratch from rodents but can also result from handling rodents or their secretions.<br /><br />A case study highlights a 19-year-old male who developed fever, rash, and joint pain after handling live rats as pet food. Initial misdiagnosis was due to nonspecific symptoms mimicking other viral illnesses. Upon hospital admission, blood cultures identified the presence of *S. moniliformis*, confirming RBF. The patient, who had no history of direct rat bites, was successfully treated with ceftriaxone.<br /><br />RBF's clinical features include fever, polyarthralgia, and skin rash. Complications can include abscesses, endocarditis, nephritis, and meningitis, with a significant untreated mortality rate of about 13%. Diagnosis challenges arise due to the rarity of the disease, nonspecific symptoms, and difficulty in isolating the fastidious bacteria, which require enriched media and specific growth conditions. Identifying *S. moniliformis* through newer microbiological technologies like MALDI-TOF and molecular tests has improved diagnostic accuracy.<br /><br />Preventative measures for those handling rodents include proper hand hygiene and avoiding close contact like kissing pets. Enhanced awareness among medical professionals and the public, along with improved diagnostic tools, are crucial for timely and accurate identification and treatment of RBF.<br /><br />The commentary concludes that despite being rare and underdiagnosed, RBF should be considered in patients with relevant exposure history and presenting symptoms, emphasizing the importance of comprehensive patient history and advanced laboratory assays for effective diagnosis.

Keywords

Rat-bite Fever

bacteremia

Streptobacillus moniliformis

Spirillum minus

zoonotic infection

diagnostic challenges

fever

rash

joint pain

ceftriaxone