Drinking Water Woes

Legionella and Campylobacter are common bacteria in waterborne disease outbreaks in the US

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) We expect our water to be fresh, clean and hydrating. But on occasion, this all-important liquid can become contaminated and even cause outbreaks of illness.

A new study looked at outbreaks of waterborne disease associated with drinking water in the US to determine major areas of concern.

The study found that Legionella and Campylobacter were the most common bacterial culprits behind outbreaks of waterborne disease in the US, and that vigilance is needed to properly maintain public water supplies and plumbing systems.

"Drink plenty of water."

This study, led by Elizabeth D. Hilborn, DVM (Doctor of Veterinary Medicine), of the US Environmental Protection Agency, examined data obtained from the Centers for Disease Control and Prevention's (CDC) Waterborne Disease and Outbreak Surveillance System.

Dr. Hilborn and colleagues looked at the surveillance information for waterborne disease outbreaks in the US during 2009 to 2010, the most recent time period for which the finalized data was available.

The researchers found that there were 33 outbreaks associated with drinking water reported to CDC during this time. Due to these outbreaks, which occurred in 17 states, 1,040 illnesses, 85 hospitalizations and nine deaths occurred.

A bacteria called Legionella was the most common cause of outbreak, hospitalization and death. According to CDC, this bacteria is found naturally in the environment (often in warm water), and while most people exposed to it do not become ill, it can sometimes lead to a type of pneumonia called Legionnaires' disease.

Legionella caused 19 outbreaks (57.6 percent), 72 illnesses (7 percent), 58 hospitalizations (68 percent) and eight deaths (89 percent).

A bacteria called Campylobacter caused fewer outbreaks, hospitalizations and deaths during 2009 to 2010, but more illnesses. Campylobacter can occur in contaminated water, poultry, produce or unpasteurized dairy products. It often causes symptoms like diarrhea, fever and abdominal pain, but can occasionally cause life-threatening infections in people with compromised immune systems, says CDC.

Campylobacter was responsible for four outbreaks (12 percent), 812 illnesses (78 percent), 17 hospitalizations (20 percent) and zero deaths.

"The drinking water outbreaks reported during this surveillance period highlight emerging and persisting public health challenges associated with drinking water systems, including Legionella in building plumbing systems, contamination of untreated ground water in public water systems and private wells, and deficiencies in the public drinking water system infrastructure," wrote Dr. Hilborn and colleagues.

"Outbreaks associated with building plumbing systems highlight the need for interventions to reduce the growth of pathogens within plumbing systems," they wrote.

Problems with Legionella in plumbing systems led to 57.6 percent of outbreaks, untreated ground water was involved in 24.2 percent of outbreaks and problems with water distribution systems were involved with 12.1 percent of outbreaks.

The study authors noted that outbreaks associated with federally regulated public water systems did continue on a declining trend seen in the past several years. However, outbreaks do continue to occur and illnesses result, which the authors say highlights the need for continued vigilance in terms of water management and sanitation.

Dr. Hilborn and colleagues also stressed the need for further research into the best ways to control Legionella and prevent outbreaks.

The study authors noted that reporting processes vary from local government to local government, so data on outbreaks may not be complete.

This study was published online September 5 in the CDC's Morbidity and Mortality Weekly Report (MMWR). No conflicts of interest were reported.

Review Date: 
September 5, 2013
Last Updated:
September 5, 2013