NEHA May 2024 Journal of Environmental Health

ADVANCEMENT OF THE SCIENCE

TABLE 4

Positive Environmental Samples via qPCR, Rapid qPCR, and Standard Culture (ISO 11731) for Legionella in New York During the 2019–2021 Outbreak

Sample Type

# of Samples Collected

Legionella spp. via qPCR

Lp via qPCR

Legionella spp. via Standard Culture**

Lp via Standard Culture ***

Lp via Rapid qPCR

Wastewater treatment plant

3

0

1

0

1

0

Cooling tower basin Cooling tower swab Patient case residence

22 10 29

8 0

4 0 0 1 2 0

5 0 0 1 1 0

9 2 0 1 2 0

3 2 0 0 0 0

12

Hot tub

2 3 5

0 0 1

Hot tub swab

Other nonpotable water source *

Total

74

21/45

8/45

7/45

15/74

5/30

*Noncooling tower swab samples (e.g., decorative fountains, baseball field irrigation system). **One laboratory did not speciate culture results; those samples were considered positive for Legionella spp. ***Some culture samples were split and submitted to numerous labs. Preference was given to the sample reported as positive if results did not match. Overall, seven cooling tower samples were positive for serogroup 1 and two samples were positive for serogroup 5. Note. Totals show the number of positive results out of the total number of samples split for analysis. Lp = Legionella pneumophila ; qPCR = quantitative polymerase chain reaction.

TABLE 5

Standard Culture, qPCR, and Whole Genome Sequencing Results From 2021 Environmental Samples

WGS Link

Date

Sample

Standard Culture (ISO 11731)(CFU/ml)

Standard qPCR

WC-EBL (CFU/ml)

Cube qPCR (GU/ml)

6/14/2021 6/16/2021 7/16/2021 7/16/2021 7/16/2021 7/16/2021 7/16/2021 7/16/2021 8/12/2021 8/12/2021 8/12/2021 8/12/2021

Cooling tower E

16 (Lp1)

– –

– –

– –

No No No No No

Bar basement spigot

ND ND

Tower 2 (E facility)

Legionella spp. Legionella spp.

ND 7.2

ND ND

Cooling tower E

30 (Lp5)

Tower 3 (E facility)

ND

Lp1 Lp1 Lp1 Lp1

20

11

Hot tub water sample Hot tub air/water swab Hot tub filter swab Other cooling tower basin 1 Hot tub water sample

5 (Lp1)

0.8 ND

– – – – – – –

Yes Yes Yes

– –

3,450

12 (Lp1)

No

ND ND ND

– – –

– – –

No No No

Hot tub swab

Other cooling tower basin 2 Other cooling tower basin 3

8/12/2021

ND

No

Note. Lp = Legionella pneumophila ; ND = not detected; qPCR = quantitative polymerase chain reaction; WC-EBL = Wadsworth Center Environmental Biology Laboratory; WGS = whole genome sequencing.

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Volume 86 • Number 9

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