Waterborne diseases: still a challenge

Waterborne diseases: still a challenge

Susan Goldhaber*

Image : Petra from Pixabay

One of our country’s greatest public health success stories in the 20^e century was the disinfection of drinking water, which played a key role in eliminating cholera and typhoid as major killer diseases in the United States. Waterborne diseases remain a significant problem worldwide. What are the waterborne diseases that still afflict us, and what should be done?

The first city in the United States to systematically disinfect water was Jersey City, New Jersey, in 1908. Water disinfection is a general term that encompasses all methods of killing germs present in the potable water. The main methods of disinfection are chlorine, ozone, ultraviolet rays and chloramines.

Waterborne diseases today

Although waterborne diseases have been greatly reduced in the United States, they have not been eliminated. Today, most waterborne illnesses are not caused by inadequate disinfection at drinking water treatment plants, but by microbes that grow and spread in building plumbing and water recreation areas. such as swimming pools and hot tubs. These microbes grow in biofilms (accumulation of bacteria) that attach themselves to the walls inside pipes, swimming pools and plumbing fixtures.

Also, many illnesses today are not caused directly by drinking water, but by inhaling tiny droplets of contaminated water. There legionellawhich causes Legionnaires’ disease, is an example of this type of microbe.

It is difficult to get an accurate count of waterborne illnesses and deaths because states report waterborne illnesses to Centers for Disease Control and Prevention (CDC) through various surveillance systems, none of which adequately captures all waterborne illnesses and deaths. In some cases, outbreaks are investigated by local and state public health officials and not reported to CDC. Some of the most prevalent waterborne diseases are not even included in the National Notifiable Diseases Surveillance System of CDCwhich monitors approximately 120 diseasesincluding nontuberculous mycobacteria, otitis externa and Pseudomonas.

Until recently, there was no national tally of the number of deaths from waterborne pathogens in the United States. A article of 2017 documented 6,301 deaths between 2003 and 2009 due to 13 waterborne infections [1]. And article of 2021 looked at US data from 2000 to 2015 and estimated that there were 118,000 hospitalizations and 6,630 deaths from waterborne illnesses.

Legionellosis

Legionnaire’s disease eis probably the best known of all waterborne diseases. It was discovered after an outbreak of pneumonia among American Legionnaires attending a convention in Philadelphia. The cause was determined to be the bacteria Legionella which reproduced in the cooling towers of the hotel’s air conditioning system and then spread throughout the building. Legionellosis is a serious respiratory disease characterized by fever, cough, chest pain and diarrhea. The bacterium Legionella can also cause Pontiac fever, a flu-like illness that is usually self-limiting and less severe.

Legionella is present in fresh water and rarely causes disease. However, in plumbing systems, Legionella can multiply and cause illness. People become infected when small water droplets containing the bacteria get into the air and people breathe them in. In 2014, an estimated 995 deaths from Legionnaires’ disease were estimated.

The reapers

Typhoid fever and cholera are the two diseases responsible for most deaths worldwide. Both are rare in the United States.

The typhoid fever is caused by bacteria Salmonella typhi present in contaminated food or water. Although related, this bacterium is not the same as the one that causes poisoning by Salmonella (salmonellosis) from food. In the 1900s, tens of thousands of cases of typhoid fever were recorded in the United States; today, less than 400 cases per year are reported, most occurring in international travellers. Despite the availability of a vaccine, typhoid fever remains a global problem, with about 11 to 20 million cases and 128,000 to 161,000 deaths per year. Most of these cases occur in poor countries in South Asia and sub-Saharan Africa.

The choleracaused by bacteria Vibrio cholera, causes acute and intense diarrhea. It has been around for centuries, but quickly spread around the world in the 19th century.^e century and was first detected in the United States in 1832. There were four cholera pandemics between 1832 and 1875. A fifth (1891-1896) and sixth (1899-1923) pandemics did not affect North America and Western Europe due to advances in water sanitation. According to’OMS, the seventh and current pandemic began in Indonesia in 1961 and has affected 120 countries, largely poor nations, mainly as a result of natural disasters such as earthquakes, droughts and floods. Worldwide, it is estimated that there are between 1.3 and 4 million cases of cholera and between 21,000 and 143,000 deaths per year, which underlines the importance of clean water. Cholera is very rare in the United States today (it is estimated that there are up to five cases a year), with most cases due to international travel or consumption of contaminated food.

Regulation ofEPA

L’EPA has three main rules for controlling microbes in public drinking water systems [2].

• 

  Revised rule on total coliforms : It establishes a maximum contaminant level (MCL) for Escherichia coli (E. coli) in drinking water. E. coli is a large group of bacteria which, when found in water, are a strong indicator of contamination from sewage or animal waste and indicate that other waterborne microbes may be present.

• Surface water treatment rule : It requires that all drinking water systems that use surface water use disinfection capable of eliminating 99.9% of viruses, Giardia a you Cryptosporidium. The Giardia and the Cryptosporidium are two protozoa that cause gastrointestinal upset characterized by diarrhea, stomach cramps, and nausea.

• Groundwater rule : Groundwater is generally cleaner and contains fewer contaminants than surface water, and not all drinking water systems using groundwater require disinfection. This rule requires groundwater systems to determine if they are likely to be contaminated with feces and, if so, to disinfect and take other measures to prevent the spread of viruses.

Water treatment plant operators must carefully manage the amount of disinfectants, such as chlorine, that they add to the water. Indeed, additional regulations of theEPA Limit disinfectant by-products, which are the chemical compounds formed when chlorine or other disinfectants react with organic compounds in the water, creating hazardous chemicals.

What to do ?

There is no easy solution to eliminating waterborne diseases today. The United States has made tremendous progress in eliminating waterborne diseases. We need better data and non-traditional solutions to leverage our progress.

For public water supply systems, the regulations of theEPA do a good job of preventing contamination at the treatment plant. If you have a private well, you should perform microbial contamination testing. However, the problem is that microbes often hide in plumbing systems and cooling towers, beyond the reach of traditional regulations.

Data is essential to developing solutions. We don’t even know the extent of the problem! The available data is a patchwork of information from many sources. THE CDC should work with state and local public health agencies to develop a national waterborne disease data collection system.

In addition, a combination of public-private partnerships should be in place to address drinking water contamination issues beyond the treatment plant. For example, the CDC developed a set of recommendations for offices and the hospitals, with concrete measures to reduce the spread of Legionella and other microbes in their buildings. These programs should be extended to hotels, recreation facilities and other establishments that often unknowingly become sources of waterborne disease. [1].

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[1] Microbes include: Campylobacter, Cryptosporidium, E. coli, GiardiaHepatitis A, Salmonella, Shigella non-typhoid, amoebas free, Legionella (Legionnaire’s disease), Non-tuberculous mycobacteria, Otitis externa, Pseudomonas vibrio.

[2] These rules do not apply to private wells and other non-public drinking water systems.

* Susan Goldhaber, MPH, is an environmental toxicologist with over 40 years of experience in federal and state agencies as well as in the private sector. She is particularly interested in chemicals found in drinking water, air and hazardous waste. Her current focus is on translating scientific data into information that can be used by the public.

Source : Waterborne Diseases: Still a Challenge | American Council on Science and Health (acsh.org)