After inmate dies of Legionnaires’, Stockton prison works to kill bacteria

California state officials have initiated a chlorine water treatment to clear out deadly bacteria that are the source of Legionnaires’ disease from several facilities in the Central Valley.

The measure is part of a larger investigation into the source of two confirmed cases of the disease at a Stockton facility, one of which resulted in the death of an inmate in March.

The treatment, which began Wednesday morning, came after environmental testing showed Legionella bacteria were present at the California Health Care Facility and the Northern California Youth Correctional Center, the state corrections department said in a news release. The process aims to disinfect water systems in about 115 buildings.

In addition to the inmate who died in March, a second inmate tested positive for Legionnaires’ disease. Results are still pending in one additional case after the California Health Care Facility — which holds more than 2,700 inmates and about 4,000 employees — examined 30 cases of pneumonia among its patients to determine whether any also were infected with Legionnaires’.

Legionnaires’ is a type of pneumonia that spreads when people breathe in water droplets containing the Legionella bacteria. Outbreaks tend to occur when a building’s water or cooling systems are contaminated, although the illness does not spread from person to person.

The facilities “discontinued the use of potable water, installed self-filtering shower heads, stopped using yard misters and power washers, and shut off the drinking-water fountains and instant hot water dispensers,” the corrections department statement said. “Bottled water is being provided to everyone who lives and works in the facilities and more self-filtering shower heads are on order.”

After the chlorine treatment, another round of environmental testing will be conducted.

Around 6,000 people are diagnosed with Legionnaires’ disease nationwide each year, and about 1 in 10 die from it, according to the U.S. Centers for Disease Control and Prevention.

The last major Legionnaires’ outbreak in California was in 2017 at Disneyland, during which 22 people fell ill and one died. State officials attributed the outbreak to the amusement park’s air-conditioning system, which carried high levels of Legionella bacteria.