Sources of water in a building can be sampled to detect colonization by a Legionella species. This can help determine the source of an outbreak or to prevent its occurrence.
Sampling during an outbreak is more extensive than for a routine survey. More samples are taken from suspected sources and from areas where infected people were located.
It is important that each sample is properly labeled and identified. The exact site, volume and date should be recorded.
Samples need to be plated on specific media designed for isolation of Legionella. A dilute sample needs to be concentrated first.
|
Water Source |
Sample Collected |
|
large body of water or major conduit |
10 liters |
|
most water sources |
1 liter |
|
small collection of water |
100 mL |
|
drain or faucet |
moist swab |
Bodies of water:
(1) creeks or ponds
(2) water treatment plant
(3) pump house
(4) fire hydrant
(5) decorative fountains
(6) swimming pools
(7) bodies of stagnant water
Sources of potable water to a building:
(1) incoming water
(2) holding tanks or cisterns
Air conditioning and water handling systems
(1) demineralizer inflow and outflow
(2) air compressors
(3) ice makers
(4) cooling towers
(5) evaporative condensors
(6) water softeners
(7) hot water heaters
(8) hot water conduits
(9) circulating pumps
(10) sump pumps
(11) fire sprinkler system
(12) air conditioning units
(13) bathrooms (faucet, showers and drains)
(14) air humidifiers
Hospital-related:
(1) pharmacy
(2) whirlpools or spas
(3) respiratory care
(4) intensive care unit
(5) patient rooms
(6) hemodialysis
In addition, air samples can be collected in areas where people became infected to detect infected water droplets. This is best done with an environmental air sampler onto specific Legionella media.
Specialty: Infectious Diseases
ICD-10: ,
