{"id":1794,"date":"2019-02-05T19:23:30","date_gmt":"2019-02-05T19:23:30","guid":{"rendered":"http:\/\/www.imegcorp.com\/?p=1794"},"modified":"2022-09-29T11:19:44","modified_gmt":"2022-09-29T16:19:44","slug":"mitigate-your-facilitys-risk-for-an-outbreak-of-legionnaires-disease","status":"publish","type":"post","link":"https:\/\/www.imegcorp.com\/insights\/blog\/mitigate-your-facilitys-risk-for-an-outbreak-of-legionnaires-disease\/","title":{"rendered":"Mitigate your facility\u2019s risk for an outbreak of Legionnaire\u2019s disease"},"content":{"rendered":"

By Dave Bodenschatz<\/p>\n

With nearly 7,500 people contracting Legionnaire\u2019s disease in 2017 \u2013 a five-fold increase since 2000 according to the\u00a0Centers for Disease Control and Prevention\u00a0\u2013 healthcare organizations are assessing the safeguards in place to minimize the risk the acquired disease poses to their patients and staff. However, the disease\u2019s bacteria can exist in any facility that has domestic water systems, a cooling tower, pool, hot tub, or fountain.<\/p>\n

\"\"
This illustration depicts a 3D computer-generated image of a group of Legionella pneumophila bacteria. \u00a9 CDC<\/figcaption><\/figure>\n

Legionnaire\u2019s disease is caused by the Legionella pneumophilia (Lp) bacteria, which occur naturally and exist in most water systems. The bacteria grow and thrive in stagnant water at a temperature between 77\u00b0F and 108\u00b0F but can multiply in temperatures between 68\u00b0F and 122\u00b0F. Infection is generally acquired by inhaling steam or mist from contaminated water from such sources as hot tubs, showers, aerated faucets, fountains, cooling towers, and stagnant domestic water piping that are not properly cleaned and disinfected. People over age 50, transplant patients, those who are immune-suppressed, have chronic lung disease, or a history of smoking are more prone to contracting the disease. Thus, patients in a healthcare setting can be at greater risk.<\/p>\n

Several organizations including the CDC and ASHRAE have published standards and guidelines on assessing and minimizing Legionella risk and how to mitigate the bacteria when discovered in domestic water systems. Following are several key strategies based on those standards and guidelines.<\/p>\n

 <\/p>\n

Domestic Hot Water Systems<\/h1>\n

System survey<\/strong><\/p>\n

Since Legionella thrives and grows in stagnant and tepid water, it is recommended that a survey be performed on any existing domestic water system. This survey should include a domestic water system diagram.<\/p>\n

The survey will review the domestic system for sparsely used fixtures, un-circulated hot water supply piping and possible dead legs \u2013 a length of pipe that water doesn’t move through, like a hot water pipe that was capped when the faucet it ran to was moved (creating plumbing with no flow and an increased risk of bacteria growth)William Hill free bets. Once the current system is analyzed, a plan of correction should be enacted to address the observed issues.<\/p>\n

Domestic hot water temperature control<\/strong><\/p>\n

The temperature of water affects the life cycle of the Lp bacteria. Sources vary slightly on exact temperatures, but the following are generally accepted ranges:<\/p>\n

Below 68\u00b0 F: Lp survive but are dormant<\/p>\n

68\u00b0 F to 122\u00b0 F: Lp growth range<\/p>\n

131\u00b0 F: Lp die within 5 to 6 hours<\/p>\n

140\u00b0 F: Lp die within 32 minutes<\/p>\n

151\u00b0 F: Lp die within 2 minutes<\/p>\n

158\u00b0 F: Disinfection level \u2013 instantaneous kill<\/p>\n

\"\"
A CDC microbiologist pours water samples from a building experiencing a Legionnaire\u2019s outbreak into a filtration system to test for Legionella. \u00a9 CDC<\/figcaption><\/figure>\n

Historically, most plumbing codes and jurisdictions recommended domestic hot water systems be stored at 140\u00b0 F to kill the Lp. These systems often used a central mixing station to mix the water down to an acceptable range of 110\u00b0 to 120\u00b0 F. Water would then be circulated through the building in this range. (Note that this temperature is in the prime Lp growth range.) Today, however, most international, state, and local plumbing codes are being revised to require domestic hot water systems to produce, store, and circulate the water at 140\u00b0 F. This will require a mixing valve at each fixture to reduce scald risks.<\/p>\n

Systems should be circulated at \u2265140\u00b0 F as close as possible to the point of use to reduce the chance of dead legs and reduce the time for water to flow through the fixture. A plan also should be in place to periodically and randomly test \u201chigh risk\u201d fixtures for Legionella contamination.<\/p>\n

Some codes are considering requiring the system to produce, store, and circulate water at 160\u00b0 F to promote continuous disinfection. While this may help disinfect the system, it causes other concerns:<\/p>\n

A. Fixtures that do not have mixing valves risk scalding or burns to the user. Common fixtures include commercial kitchen wash sinks, dishwashers, and janitor sinks.<\/p>\n

B. At locations that include a mixing valve, failure of that valve could again expose users to scalding and burns.<\/p>\n

C. Additional energy consumption is needed to maintain hotter water.<\/p>\n

D. Additional insulation is required on the system piping to minimize heat loss and increase safety.
\nAdditional suggestions for domestic water systems include:<\/p>\n