Food Safety Infectious Diseases Public Health Preparedness & Response

Celebrating Lab Week — Case Study 1

Happy National Medical Laboratory Professionals Week!

As a fun activity during the week several programs at APHL will be posting fun case studies related to the work being done in public health laboratories across the country. Today’s case study comes from Infectious Disease, Food Safety, and Emergency Preparedness.

Case Study

Mr. Fudd presents in the emergency room in Chicago with fever, lethargy, severe pharyngitis, tonsillitis and a striking swelling of his neck. The ER Physician ordered Rapid Streptococcus A Dtesting, gram stain, and respiratory cultures.

Two days following the first patient presentation, three additional Fudd family members present to the same emergency room with similar symptoms.

All patient specimens were sent to the laboratory for ordered laboratory testing. The lab results included the following:

Laboratory Tests —

(Photo: Blood Agar Plate Growth at 48 hours)

  • Rapid Streptococcus A: Negative
  • Gram Stain: Gram Negative Rods
  • Culture incubated at 37C for(24 hours): Pin point colonies on Blood agar Plate and Chocolate agar
  • Culture incubated at 37C for (48 hours): Grey, white, translucent colonies on Blood agar Plate and Chocolate agar; Clear White Non Lactose Fermenting colonies on MacConkey agar

Biochemicals —

(Photo: Gram Stain of Culture Isolate)

  • Catalase: Positive
  • Oxidase: Negative
  • Urease: Negative
  • Indole: Negative

What would your laboratory do next?

Please include your comments/answers below. APHL is excited to hear what your laboratory would do next!  The response and case investigation will be posted this afternoon.  Stay tuned…

1 Comment

  • First, I would clarify the source of the specimen. Is this a throat culture, or a lower respiratory tract culture?

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