Legionella and Water-borne Pathogens – Commercial

Legionella and Water-borne Pathogens

What You Need to Know

Legionella-gram negative bacteria found in man-made bodies of water and some soils with approximately 50 different species-Legionella pneumophila accounts for most disease

Greatest exposure risk- smokers, cancer patients, elderly, transplant patients

Transmission Requirements

LEVEL OF CONTAMINATION in the water source
TYPE OF LEGIONELLA in the water system
SUSCEPTIBILITY of the person exposed, and
INTENSITY of the exposure to the contaminated water
Transmission- Inhalation and/or aspiration of contaminated water

Risk Factors for Growth-

Water stagnation
Water temperatures
Scale, sediment, other nutrient accumulation in water systems

What You Need to Do

Designate water management team knowledgeable about building water conditions/issues

Develop routine inspection, maintenance, disinfection processes for all areas of exposure such as cooling towers, decorative fountains, whirlpools, evaporative cooling systems, etc.)

Institute secondary disinfection systems and develop emergency disinfection programs

Develop Hazard Analysis Critical Control Point (HACCP) program for all buildings with respect to managing water quality at critical building control points

Myths and Misconceptions

Studies indicate that Legionella colonization of water supply systems in building is common- TRUE

Legionella can be present in a water system without being associated with disease-TRUE

Chlorination process used to purify domestic water systems will kill all Legionella bacteria-FALSE

Legionella can be transmitted easily from person to person and therefore precautions must be taken-FALSE