Q- A 25-year-old woman comes to the office because of a 3-day history of fever, chills, severe headache, weakness, muscle pain, loss of appetite, vomiting, diarrhea, and moderate abdominal pain. She is in nursing school and returned from a medical mission’s trip in West Africa 10 days ago. Her symptoms began abruptly while she was shopping in a supermarket after her return. Temperature is 39.0°C (102.2°F), pulse is 100/min, respirations are 22/min, and blood pressure is 110/70 mm Hg. The patient appears ill and in mild respiratory distress. Physical examination discloses poor skin turgor and hyperactive bowel sounds. Muscle strength is 4/5 throughout. Laboratory studies show leukopenia and thrombocytopenia.
Which of the following is the most sensitive and specific test for detection of the suspected viral genome in this patient?
(A) Microarray analysis
(B) Northern blot
(C) Reverse transcription-polymerase chain reaction test
(D) Southern blot
(E) Western blot
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Answer and Explanation
This patient presents with acute febrile illness, myalgia, gastrointestinal symptoms (vomiting, diarrhea, abdominal pain), leukopenia, and thrombocytopenia after recent travel to West Africa, raising concern for Ebola virus disease (EVD) or another viral hemorrhagic fever (VHF) (e.g., Lassa fever, Marburg virus).
RT-PCR is the most sensitive and specific test for detecting viral RNA, especially in early infection before antibodies develop.
Microarray analysis – Used for detecting multiple pathogens at once but lacks the sensitivity and specificity of RT-PCR for a specific viral genome.
Northern blot – Detects RNA but is not practical for rapid clinical diagnosis.
Southern blot – Detects DNA, but Ebola is an RNA virus, making this technique irrelevant.
Western blot – Detects proteins, typically used for antibody detection, which is not the best early diagnostic method.
The correct answer is C
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