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Volume 24, Number 10—October 2018

Two Community Clusters of Legionnaires’ Disease Directly Linked to a Biologic Wastewater Treatment Plant, the Netherlands

Anna D. LoenenbachComments to Author , Christian Beulens, Sjoerd M. Euser, Jeroen P.G. van Leuken, Ben Bom, Wim van der Hoek, Ana Maria de Roda Husman, Wilhelmina L.M. Ruijs, Alvin A. Bartels, Ariene Rietveld, Jeroen W. den Boer, and Petra S. Brandsema
Author affiliations: European Centre for Disease Prevention and Control, Stockholm, Sweden (A.D. Loenenbach); National Institute for Public Health and the Environment, Bilthoven, the Netherlands (A.D. Loenenbach, J.P.G. van Leuken, B. Bom, W. van der Hoek, A.M. de Roda Husman, W.L.M. Ruijs, A.A. Bartels, P.S. Brandsema); Municipal Health Service Hart voor Brabant, ’s-Hertogenbosch, Tilburg, the Netherlands (C. Beulens, A. Rietveld); Regional Public Health Laboratory Kennemerland, Haarlem, the Netherlands (S.M. Euser, J.W. den Boer); Utrecht University, Utrecht, the Netherlands (A.M. de Roda Husman)

Main Article

Table 2

Results of environmental samples taken during investigation of 2 community clusters of Legionnaires’ disease directly linked to a biologic wastewater treatment plant, Boxtel, the Netherlands, October 2016–December 2017*

Location of samples Sampling date, wk/y CFU/L Legionella pneumophila
serogroup ST
Water samples†
Pond 1 (low aeration) 48/2017 2.0 × 106 sg1
50/2017 5.6 × 107 sg1 ST1646
Pond 2 (no aeration) 48/2017 7.1 × 108 sg1 ST1646
50/2017 19.2 × 108 sg1 ST1646
Pond 3 (high aeration) 48/2017 15.0 × 108 sg1 ST1646
50/2017 22.6 × 108 sg1
Municipal waste water treatment plant
Influent 39/2017 1.0 × 105 sg1 ST1646
Pond 39/2017 2 × 103 sg1 ST1646
River midstream 39/2017 2 × 103 sg1 ST1646
Riverside 39/2017 2 × 104 sg1 ST1646
Fountain, city center 50/2016 Negative
39/2017 Negative
WCTs and air scrubbers next to BWTP, industrial area
50/2016 Negative
39/2017 Negative
48/2017 Negative
4 WCTs, industrial area 50/2016 Negative
5 WCTs, industrial area 39/2017 Negative
Misting device, industrial area

Other environmental samples†
Biologic waste water treatment plant
Air sample inside pond 3 tent 50/2017 Positive sg1
Swab inner surface pond 3 tent 50/2017 Positive sg1 ST1646

*Source: Database National Reference Laboratory for Legionella, Haarlem, the Netherlands. BWTP, biologic wastewater treatment plant; sg, serogroup; ST, sequence type; WCT, wet cooling tower.
†Water samples were analyzed with an accredited in-house developed method based on ISO 11731:2017, with an additional step of acid treatment. Air samples were collected using a SASS 2300 air sampler (Research International, Seattle, WA, USA), and analyzed in with an accredited in-house developed method based on ISO 11731:2017.
‡Sequence type profile was incomplete because of technical problems experienced during mompS typing; however, for all 6 available alleles, results were in accordance with the ST1646 profile (flaA, 2; pile, 10; asd, 14; Mip, 10; mompS, not available; proA, 4; neuA, 11).

Main Article

Page created: September 16, 2018
Page updated: September 16, 2018
Page reviewed: September 16, 2018
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