In the context of cholera surveillance, a case is defined as a suspected case when a person aged 5 years or more develops acute watery diarrhoea with or without vomiting. Which Vibrio cholerae serogroup is responsible for the El Tor biotype currently causing pandemics?
- A V. cholerae O139 (Bengal)
- B V. cholerae O1 Classical biotype
- C V. cholerae O1 El Tor biotype ✓
- D V. cholerae O1 Biotype Haitian variant
Correct answer: C. V. cholerae O1 El Tor biotype
Explanation
The 7th (current) pandemic is caused by V. cholerae O1 El Tor biotype, which replaced the Classical biotype in the 1960s. V. cholerae O139 (Bengal) caused a large outbreak in 1992-93 in India/Bangladesh but did not cause a global pandemic. The Classical biotype caused the earlier 6 pandemics. The El Tor biotype produces less cholera toxin per bacterium but survives longer in the environment, sustaining epidemics. Variants of El Tor (e.g., altered El Tor) have been identified more recently but are still O1 El Tor.
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.