After manual cleaning, a flexible gastroscope used on a patient with suspected peptic ulcer disease is immersed in 2% glutaraldehyde solution for high-level disinfection. What is the minimum immersion time required at 20 degrees Celsius to achieve high-level disinfection?

• A 5 minutes
• B 10 hours
• C 3 hours
• D 20 minutes ✓

Explanation

Glutaraldehyde 2% achieves high-level disinfection of semi-critical devices such as endoscopes in 20 minutes at 20 degrees Celsius, provided channels are flushed and fully immersed. Killing of bacterial spores requires much longer exposure, typically around 10 hours, which is why option B represents sterilisation rather than disinfection. Five minutes is insufficient even for vegetative bacteria in channel lumens where organic load persists.

Reference: Ananthanarayan and Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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