Among the following chemical disinfectants, which is the most commonly used agent for high-level disinfection of endoscopes in Indian hospitals?

Explanation

## High-Level Disinfection of Endoscopes **Key Point:** Glutaraldehyde 2% is the most widely used and most common high-level disinfectant for endoscopes in Indian hospital practice. ### Why Glutaraldehyde Is the Standard Glutaraldehyde is an aldehyde that: - Rapidly inactivates bacteria, viruses, fungi, and spores - Achieves high-level disinfection in 3–10 hours (depending on concentration and temperature) - Is cost-effective and widely available in India - Has been the gold standard for endoscope disinfection for decades - Is recommended by WHO and most national infection control guidelines ### Mechanism of Action Glutaraldehyde cross-links proteins and nucleic acids in microorganisms, causing: 1. Denaturation of enzymes 2. Disruption of cell membrane integrity 3. Inactivation of nucleic acids 4. Rapid bactericidal, virucidal, and sporicidal activity ### Comparison of High-Level Disinfectants | Agent | Concentration | Contact Time | Sporicidal | Cost | Common Use | |-------|---------------|--------------|-----------|------|------------| | Glutaraldehyde | 2% | 3–10 hrs | Yes | Low | Endoscopes (most common) | | Peracetic acid | 0.35% | 3–12 min | Yes | High | Automated systems | | Hydrogen peroxide | 6% | 30 min–6 hrs | Yes (high conc.) | Medium | Endoscopes (alternative) | | Chlorhexidine | 4% | 30 min | No | Low | Intermediate disinfection only | **High-Yield:** Glutaraldehyde is sporicidal (kills bacterial spores) and is therefore suitable for high-level disinfection, whereas chlorhexidine is NOT sporicidal and is only intermediate-level. **Mnemonic:** **GAPS** — Glutaraldehyde, Aldehydes, Peracetic acid, Sporicidal (these three are high-level disinfectants). ### Clinical Pearl In Indian hospitals, glutaraldehyde 2% remains the most practical choice because: - It is inexpensive - Requires no special equipment (manual soaking) - Has a long shelf life when properly stored - Effective against all microorganisms including spores - Widely available and familiar to staff **Warning:** Chlorhexidine, despite being commonly available, is NOT suitable for high-level disinfection of endoscopes because it is not sporicidal and does not achieve the required microbicidal spectrum.