2014 — June-Oct, 2015, Legionella pneumophila outbreak (Legionaries’ Disease), Flint, MI-12

–12 Hersher. “Lethal Pneumonia Outbreak Caused by Low Chlorine in Flint Water.” NPR, 2-5-2018.
–12 Klein. “Remembering the Legionnaires’ Outbreak.” History.com. 11-13-2020 update.
— 9 MDHHS. “MDHHS issues 2015 Legionnaires Disease Report for Genesee County.” 1-21-2016.
–5 June 2014-March 2015
–4 May-Oct 2015

Narrative Information

Hersher: “An outbreak of Legionnaires’ disease that killed 12 people and sickened at least 87 in Flint, Mich., in 2014 and 2015 was caused by low chlorine levels in the municipal water system, scientists have confirmed. It’s the most detailed evidence yet linking the bacterial disease to the city’s broader water crisis. In April 2014, Flint’s water source switched from Lake Huron to the Flint River. Almost immediately, residents noticed tap water was discolored and acrid-smelling. By 2015, scientists uncovered that the water was contaminated with lead and other heavy metals.

“Just months after the water source changed, hospitals were reporting large numbers of people with Legionnaires’ disease. ‘It’s a pneumonia, but what’s different about it is, we don’t share it like we do the flu or common cold,’ explains Michele Swanson of the University of Michigan, who has been studying Legionnaires’ for 25 years. ‘It’s caused by a bacterium, Legionella pneumophila, that grows in water.’ The bug can enter the lungs through tiny droplets, like ones dispersed by an outdoor fountain or sprinkler system, or accidentally inhaled if a person chokes while drinking. ‘If you don’t have a robust immune system, the microbe can cause a lethal pneumonia,’ she says. In a normal year, the disease is relatively rare — about six to 12 cases per year in the Flint area, according to Swanson. During the water crisis, that jumped up to about 45 cases per year….

“ ‘We know that Legionella is sensitive to chlorine in the laboratory,’ says Swanson. The chlorine makes it difficult for the bacteria to replicate, which is one reason water companies often add chlorine to their systems. But when Flint’s water source changed, the chlorine level dropped and cases of Legionnaires’ disease spiked. ‘It was the change in water source that caused this Legionnaires’ outbreak,’ Swanson says…. the disease outbreak ended when the city switched back to its original water source, even though Legionella bacteria aren’t completely gone from the water system….”

Klein: “….According to the CDC, the number of people diagnosed [with Legionaries] has increased nearly fourfold from 1,127 in 2000 to 5,166 in 2014, with the disease proving fatal in about seven percent of cases. Just last year, an outbreak in the Bronx killed 16 while another in Flint, Michigan, claimed the lives of a dozen more. Most of the 20 outbreaks averaged each year occur in buildings with large water systems and poorly maintained air-conditioning equipment.” (Klein, Christopher. “Remembering the Legionnaires’ Outbreak.” History Stores. History.com. 7-21-2016, updated 11-13-2020.)

Michigan Dept. of Health & Human Services: “Lansing, Mich. — The Michigan Department of Health and Human Services today issued its report regarding the increase of Legionnaires’ disease (LD) during 2015 in Genesee County. MDHHS cannot conclude that the increase is related to the water switch in Flint nor can we rule out a possible association at this time.

“From May 2015 through October 2015, 42 LD cases were reported in Genesee County. Data previously indicated three Legionnaires associated deaths from May 2015 through October 2015, however additional case information received has brought this number to four….

“Legionella is a type of bacteria commonly found in the environment that grows best in warm water, such as hot tubs, cooling towers, hot water tanks, potable water systems, and decorative fountains. When people are exposed to the bacteria, it can cause Legionellosis, a respiratory disease that can infect the lungs and cause pneumonia. The bacteria can also cause a less serious infection called Pontiac fever. Legionella is not transmitted person to person.

“The state today also released an updated report for cases from June 2014 to March 2015. During that time, 45 LD cases were confirmed in Genesee County, including five associated fatalities. The report issued on January 13 originally identified seven fatalities during that time period.

“Consistent with published literature, legionella related deaths are defined as fatalities that occurred within 30 days of hospital discharge. While the number of cases remain unchanged for LD in Genesee County, the total associated fatalities is now nine because some cases occurred outside of the 30 day period….”

Sources

Hersher, Rebecca. “Lethal Pneumonia Outbreak Caused by Low Chlorine in Flint Water.” NPR, All Things Considered. 2-5-2018. Accessed 3-24-2021 at: https://www.npr.org/sections/health-shots/2018/02/05/582482024/lethal-pneumonia-outbreak-caused-by-low-chlorine-in-flint-water

Klein, Christopher. “Remembering the Legionnaires’ Outbreak.” History Stores. History.com. 7-21-2016, updated 11-13-2020 Accessed 3-24-2021 at: https://www.history.com/news/the-discovery-of-legionnaires-disease

MDHHS (Michigan Department of Health & Human Services). “MDHHS issues 2015 Legionnaires Disease Report for Genesee County.” 1-21-2016. Accessed 3-24-2021 at: https://www.michigan.gov/mdhhs/0,5885,7-339-73970_71692-374458–,00.html