Did Municipal Water Distribution System Deficiencies Contribute to a Legionnaires’ Disease Outbreak in Quincy, IL?

Abstract

Fifty-eight people were sickened and 12 died from a Legionnaires' disease (LD) outbreak in Quincy, IL, in 2015. The initial outbreak investigation identified deficiencies at the Illinois Veteran's Home (IVHQ), but these did not account for four community-acquired cases that occurred concurrently with no IVHQ exposure. We broaden the investigation to evaluate seven lines of evidence and assess whether municipal drinking water supply deficiencies potentially contributed to a community-wide outbreak. Notably, 3−6 months prior to the outbreak, the primary disinfectant was changed and corrosion control was interrupted, causing a sustained decrease in disinfectant residuals throughout Quincy's distribution system. We hypothesize this created more favorable conditions for Legionella growth throughout the system and an increase in water lead levels. These municipal system deficiencies were not identified in prior investigations of the outbreak, but their impacts on public health outcomes are consistent with those of the 2014−2016 Flint Water Crisis. However, they occurred in Quincy without any legal violations in the municipal water system or public acknowledgment of community-wide health risks. This study supports the critical need for improved data collection during changes in municipal water treatment. Additional regulatory and communication requirements can better protect public health from both LD and lead.

Variable Legionella Response to Building Occupancy Patterns and Precautionary Flushing

“…The sharp increase in L. pneumophila observed during winter break 2019 may rather be linked to uncontrolled and undocumented events related to construction associated with a new building adjacent to the study site. Construction activities, depressurization (maintenance, failures), and water treatment failures have been linked to elevated levels of Legionella occurrence and/or Legionnaires’ disease incidence [ 48 , 49 , 50 , 51 ]. While it is impossible to retrospectively link these events, such connections should not be ruled out and should be the subject of future research.…”

Tap water as the source of a Legionnaires’ disease outbreak spread to several residential buildings and one hospital, Finland, 2020 to 2021

“…There was also no known incident in the water plant explaining any sudden increase in the nutrients, decrease in disinfection efficiency or any other change in the process that would cause the increase in Legionella. As reported earlier, a change in primary disinfectant can cause an interruption in the corrosion control, a decrease in disinfectant residuals and an increase in lead in the distribution system, and create favourable conditions for Legionella [23]. Similarly, Legionella clusters have been connected to a switch in raw water source from non-corrosive water to corrosive river water [24].…”

Synergy between Microwave Radiation and Silver Ions or Nanoparticles for Inactivating Legionella pneumophila

“…The number of legionellosis cases is steadily increasing. Biofilm persistence in aging infrastructure, ambient temperature changes, increased likelihood of natural disasters due to climate change, and increases in drinking-water age from prolonged inactivity (e.g., during the current pandemic and after floods , ) exacerbate Lp growth in distribution systems. , The 2014 Flint, MI, water crisis coincided with an outbreak of Legionnaires’ disease that was apparently attributable to low chlorine residual and release of iron, an essential nutrient for Lp, into the system. , A 2015 outbreak in Quincy, IL, occurred after a change in corrosion control and a decrease in disinfectant residual, among other factors . These incidents highlight the myriad factors contributing to the persistence and proliferation of Lp.…”

“…58,59 A 2015 outbreak in Quincy, IL, occurred after a change in corrosion control and a decrease in disinfectant residual, among other factors. 60 These incidents highlight the myriad factors contributing to the persistence and proliferation of Lp.…”