Where to Sample?. Objectives Environmental Sources of Legionella Determine Sources to Sample Tools Needed for Sampling How to Sample.

Where to Sample?

Objectives

Environmental Sources of Legionella

Determine Sources to Sample

Tools Needed for Sampling

How to Sample

Legionella Transmission Legionella transmission is via aerosols

— the inhalation of mist droplets containing the bacteria. Common sources include cooling towers, swimming pools, domestic hot-water systems, fountains, and similar disseminators that tap into a public water supply. Natural sources of Legionella include freshwater ponds and creeks.

Host

Aerosolized Droplets

Source

Conditions Favorable for Legionella Water Temperature 68°- 122°F (20°-

50°C) Area where water can become stagnant

and formation of a bio-film can occur. Total Chlorine Residual below .5ppm Lack of routine maintenance and

cleaning of cooling towers, decorative fountains and recreational water facilities.

Common Sources

Cooling towers are heat removal devices used to transfer process waste heat to the atmosphere.Common applications include cooling the

circulating water used in oil refineries, chemical plants, power stations and building cooling.

Common Sources

Swimming Pools

Hot Tubs

Domestic Hot Water Systems

Decorative Fountains

Natural Sources

Freshwater Ponds

Freshwater Creeks

Single Case Investigation v/s Outbreak Investigation

Single Case Investigation

Outbreak Investigation

Outbreak Environmental InvestigationNot a Routine Inspection For Legionella

Ask facility to shut off decorative fountains – but advise them not to clean or drain the fountain.

Ask the facility to close all recreational water facilities (for use by the public)on site – advise them not to super chlorinate, clean, or change/disturb any of the filter systems.

Staff needed for Environmental Assessment for

Legionella Outbreak Investigation LHD/WVDHHR/CDC

LHD StaffDIDE StaffCDC StaffOEHS District

EngineersOEHS District

SanitariansOEHS Central Office

Staff

Facility/Private Industry StaffFacility(s)

ManagementFacility(s)

Maintenance StaffCertified Pool

OperatorOther Facility Staff

Use the Legionellosis Hypothesis Generating Questionnaire and the Sample Environmental Assessment of Water Systems Form.

CDC Sample Environmental Assessment of Water Systems

Determine Where to SampleIn consultation with DIDE and CDC What type of facility? Are there any decorative fountains,

misters or other aerosol-generating devices anywhere on the facility premises?Are the decorative fountains chlorinated –

with a positive feed chlorinator? Has the facility previously associated

legionellosis cluster or outbreak?

Determine Where to SampleIn consultation with DIDE and CDC Does the facility have and recreational

water facilities? If so how many and what types.Filter type and maintenance recordsDisinfection type and recordsCleaning and maintenance schedule(s)

Determine Where to SampleIn consultation with DIDE and CDC What type of potable water supply? Potable water supply maintenance

Specifics of the potable water supply○ Hot water temperature(s)○ Chlorine residual(s)○ Interruptions in the potable water supply

Any construction or additions to potable water supply?

Where do we need to sample? Potable water supply

Recreational Water Facilities

Aerosol – Generating Devices i.e. decorative fountains, misters, etc.

○ After consultation with DIDE and CDC

Where do we send the samples?

Samples will be sent to the lab designated by CDC

After consultation with DIDE and CDC

For assistance with collecting water samples contact Office of Environmental Health Services.

What tools do you need for proper sampling? Sterile 1 liter sample bottles Sodium thiosulphate Sterile polyester swabs Sterile sample tubes Pipette/Dropper for measuring sodium

thiosulphate Thermometer pH test kit or test strips Chlorine test kit Cooler for sample storage and shipping Sample collection log

Control Sample For each sample: using a separate

control sample collected at the same timepH readingTemperatureTotal Chlorine ResidualRecord this data on a log which also includes :

a sample ID, date collected, time collected, sample type, sample description and comments include the name of person sampling.

Example Sample Collection Log

TAKING THE TEMPERATURE TOTAL CHLORINE RESIDUALAND pH OF EACH CONTROL SAMPLE

Sample Collection Water Sample

One (1) liter water sample Bio-film sample

Taken from shower heads, faucet aerators, scum line on fountains and recreational water facilities.

Sample: Potable Water, Recreational Water Facilities, Decorative Fountains, and Cooling Towers

Where to obtain Bio-film sample from scum line

Potable Water Sampling Collect water samples from the distal

point(s) of the potable hot water. Collect water sample(s) from sleeping

room(s) and any restroom as indicated from the investigation.Water Sample(s) and Bio-film sample(s)

take from showers and faucets.Sample(s) taken from the Hot Water

Heater(s) that serve the area of facility identified.

Taking a Bio-film Sample from the Shower Head and Faucet Aerator

Sampling - Swimming Pools/Hot Tubs or Other Recreational Water Facilities – Outdoor and Indoor In addition to water sample and scum

line bio-film sampleCollect sample from sand filter or sample cut

from cartridge filterBio-film from other area of the recreational

water facility where a bio-film may form.

Other areas where a Bio-Film may be found.

Sampling - Cooling Towers Cooling Towers associated with the

HVAC system on the site. Commercial Industrial Cooling Towers in

the area.○ Note: Ask about the use of biocides

Sampling and Findings

Northern Panhandle Legionella Cluster – Environmental Sampling – Facility A

Sampled the potable water system of Facility A– hot water heater, distal points of potable water system, sleeping rooms and restrooms as indicated by the questionnaires of patients.

Sampled all recreational water facilities at Facility A.

Sampled all decorative fountains at Facility A .

Northern Panhandle Legionella Cluster – Environmental Sampling – Cooling Towers

Sampled cooling towers at three (3) industrial facilities in close proximity to Facility A .

Oil RefineryOxygen and Argon gas production facility Recycling facility.

Water Sample Results - CDC Legionella pneumophila  serogroup 1

only one facility grew this serogroup○ However, this is a common strain and isolation from the

cooling tower does not definitively implicate this facility as the source of the outbreak.

○ In fact, our epidemiology indicates that only three (3) of the community cases lived or visited within a 10 mile radius of the facility during their incubation period.

Facility Date Collected Date processed Sample description Organism

1 9/08/2011 9/10/2011 Biofilm from Cooling tower

Legionella (Not Lp1) andLegionella pneumophila serogroup 1, (MAb[2] negative)

2 9/08/2011 9/10/2011 Water from pump room Legionella (Not Lp1)

3 9/08/2011 9/10/2011 Biofilm and water from cooling tower

None isolated

4 9/09/2011 9/10/2011 Water from cooling tower

Legionella (Not Lp1)

Problems Encountered Decorative Fountains had been super

chlorinated prior to sampling. Recreational Water Facilities had been

super chlorinated prior to sampling. Cartridge Filters for hot tubs had been

replaced. Shower heads were a sealed unit –

could not obtain a bio-film from sprayer.

QUESTIONS?

Judy Vallandingham R.S.

General Sanitation Program Manager

Office of Environmental Health Services – Public Health Sanitation

304-356-4341

Judy.E.Vallandingham@wv.gov

Sources CDC Procedures for the Recovery of

Legionella from the Environment. CDC Sample Environmental Assessment

of Water Systems http://www.cdc.gov/legionella/files/EnvironmentalAssessmentInstrument.pdf

ASHREA STANDARD 12-2000: Minimizing the Risk of Legionellosis Associated with Building Water Systems.

Training with CDC.