The Revised Vibrio cholerae case definition under IDSP classifies a case as 'confirmed' when:
- A Severe watery diarrhoea with dehydration plus Vibrio cholerae O1 or O139 isolated on culture ✓
- B Watery diarrhoea ≥3 times in 24 hours in a person residing in a cholera-affected area
- C Positive dark-field microscopy showing motile comma-shaped organisms
- D String test positive plus rice-water stools in a patient >5 years old
Correct answer: A. Severe watery diarrhoea with dehydration plus Vibrio cholerae O1 or O139 isolated on culture
Explanation
Confirmed cholera requires isolation of toxigenic Vibrio cholerae O1 (El Tor or classical biotype) or O139 from stool culture. Clinical suspicion alone (rice-water stools, severe dehydration) constitutes a probable or suspected case. Dark-field microscopy showing motile organisms supports presumptive diagnosis but not confirmation. String test (mucinous string formation) is a simple bedside presumptive test. The IDSP surveillance case definition strictly requires microbiological confirmation for 'confirmed' status.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.