For an acute flaccid paralysis (AFP) case investigated under polio eradication surveillance, the acceptable stool specimen criteria are:
- A One stool specimen collected within 7 days of onset of paralysis
- B Two stool specimens collected 24 hours apart, both within 14 days of onset of paralysis, reaching the laboratory within 72 hours ✓
- C Two stool specimens collected 48 hours apart, both within 30 days of onset, reaching the laboratory within 7 days
- D Three stool specimens on consecutive days within 21 days of onset of paralysis
Correct answer: B. Two stool specimens collected 24 hours apart, both within 14 days of onset of paralysis, reaching the laboratory within 72 hours
Explanation
Programme criteria require two adequate stool specimens collected at least 24 hours apart, each within 14 days of paralysis onset, transported in reverse cold chain to reach the accredited laboratory within 72 hours of collection. Adequate specimen collection rate is a core quality indicator of AFP surveillance alongside non-polio AFP rate. Specimens taken beyond 14 days lose sensitivity for wild or vaccine-derived virus isolation, invalidating options A and C.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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