US experiences around 7 million waterborne illnesses annually

Researchers estimated that the United States experiences around 7 million waterborne illnesses each year, according to findings published in Emerging Infectious Diseases.

Sarah A. Collier, MPH, an analytic epidemiologist in the CDC’s National Center for Emerging and Zoonotic Infectious Diseases, and colleagues used data from 2000 to 2015 to produce the first estimates of the overall burden of waterborne disease in the U.S.

“Despite having one of the safest drinking water supplies in the world, about 118,000 hospitalizations and 6,600 deaths from waterborne disease occur in the U.S. each year,” Collier told Healio. “The majority of hospitalizations and deaths were from diseases with respiratory or systemic effects, including Legionnaires’ disease, nontuberculous mycobacterial infections, and Pseudomonas pneumonia and septicemia. These diseases are spread through contaminated aerosolized water.”

Of the 118,000 (95% CI, 86,800-150,000) hospitalizations, nontuberculous infections were the most commonly reported, with 51,400 (95% CI, 26,800-74,100) hospitalizations, followed by otitis externa, or “swimmer’s ear,” with 23,200 (95% CI, 13,900-33,600) hospitalizations and Pseudomonas pneumonia, with 15,500 hospitalizations (95% CI, 4,130-28,100). An estimated 77,700 respiratory hospitalizations and 10,900 enteric hospitalizations were attributed to water transmission, according to the study.

Of the 6,630 deaths (95% CI, 4,520-8,870), nontuberculous infections were the most common cause, accounting for 3,800 deaths (95% CI, 1,950-5,620), followed by Legionnaires’ disease (995; 95% CI, 655-1,310) and Pseudomonas pneumonia (730; 95% CI, 185-1,460). There were an estimated 5,530 deaths from respiratory disease and 131 deaths from enteric disease attributed to waterborne transmission.

“As this paper shows, millions of people are still getting sick from waterborne illnesses every year,” Collier said. “The water disinfection and treatment methods we have in place significantly decreased waterborne diseases over the last century. It is essential that we maintain and update our drinking water infrastructure to ensure that our drinking water supply remains one of the safest in the world.”

According to Collier, the CDC has developed control and prevention recommendations for some of the pathogens discussed in the study. The CDC established the Model Aquatic Health Code, which is a set of recreational water facility guidelines to help state and local officials save time and resources when developing and updates pool codes.