California businesses are reopening after the long lockdown. But our empty offices, hotels, restaurants, and gyms may have collected more than just dust; a deadly bacteria called legionella could be growing in the pipes.

Legionella pneumophila is one of over 58 strains of Legionella bacteria that flourish in showers, sinks, cooling towers, hot tubs, decorative water features, hot water tanks, and plumbing systems. When aerosolized droplets of Legionella pneumophila are inhaled, the bacteria causes a deadly form of pneumonia known as Legionnaires' Disease. Although Legionnaires’ Disease is treatable with antibiotics, about 1 out of 10 people die from the illness; the elderly, smokers, and the immunocompromised are especially vulnerable. The CDC reported about 10,000 cases of Legionnaires’ Disease in 2018, but experts believe the true number of cases is higher. Case numbers are also on the rise; the rate of reported cases grew ninefold from 2000 to 2018. Health officials remain unsure if the trend is an artifact of better testing or indicative of environmental and demographic factors like antiquated infrastructure and a larger elderly population. If the trend continues, the US may be on track for a historic number of cases in 2021; experts fear the lockdown provided the perfect conditions for legionella to thrive and multiply. 

Before Covid-19 cases spiked, buildings constantly flushed their plumbing with chlorinated water and kept water temperatures too hot for bacteria to grow. But after the lockdown went into effect, maintaining disinfecting and sanitizing practices became difficult. Disinfectants like chlorine will disappear after a few days and need constant reapplication to remain effective. Unused hot water also stagnates and cools from safe temperatures into the bacteria’s growing range. After only a few weeks of temporary shutdown or reduced occupation, legionella can grow in the pipes. Without proper testing before reopening, these previously empty buildings could become hotspots for a new outbreak of legionella and Legionnaires Disease. 

As hospitals strain to treat the influx of Covid-19 patients, a new outbreak of Legionnaires’ Disease may further stress an overloaded system. According to CDC statistics, most cases of Legionnaires’ Disease require an initial hospitalization period. But with hospitals in California running out of bed space, there may be no place for patients to go. Some experts also fear that Covid-19 survivors are more likely to develop a serious case of Legionnaires’ Disease if exposed to the bacteria. 

With our most vulnerable populations—the elderly, the immunocompromised, and Covid-19 survivors—at risk, Californians must take a proactive stance. Building managers planning to reopen a facility should consult their water management plan to ensure the water systems will be properly tested and sanitized. The CDC has released a helpful Toolkit and guidelines for managing legionella prior to reopening. The annual Legionella Conference, hosted by the National Sanitation Foundation (NSF) Health Sciences and National Environmental Health Association, will hold a special, virtual session on March 9-10. The conference will address water management and resiliency strategies during a health crisis. 

Testing and management are the most effective tools for preventing legionella outbreaks. That is why Babcock Laboratories (Babcock Labs) offers field sampling and analysis of legionella in drinking fountains and water systems. Contact Babcock Labs to schedule your legionella testing today.