Enteric Viruses in Drinking Water: Essential Information

In our everyday lives, we rely on water for cooking, bathing, and drinking in our homes and businesses. In the United States, we often take water quality for granted, even though hidden dangers may lurk in our water supplies. Enteric viruses, a group of viral contaminants that can cause serious or even fatal illnesses, can contaminate water supplies. With a reverse osmosis water system, you can protect your health and the health of your loved ones from viral contamination. These systems purify the water we use in our homes whether it comes from municipal water sources or private wells.

What are Enteric Viruses?

Enteric viruses are a group of viruses that are one of the primary causes of foodborne and waterborne illnesses. These viruses spread through human-to-human contact or when sewage contaminates food and water sources. According to the U.S. Centers for Disease Control and Prevention (CDC), about 5.5 million people are stricken by enteric viral illnesses each year, resulting in thousands of hospitalizations and nearly 200 deaths on average.

The word enteric means “relating to or occurring in the intestines.” Enteric viruses are a large group and include some of the most common viruses implicated in waterborne illnesses. Enteric viruses include:

• Rotaviruses
• Noroviruses
• Noroviruses (Norwalk and Norwalk-like virus)
• Astroviruses
• Hepatitis A
• Hepatitis E
• Caliciviruses
• Coronaviruses
• Adenoviruses
• Toroviruses

As a group, these viruses cause diarrhea illnesses by infecting the lining of the gastrointestinal system. Certain of these viruses infect the upper small intestine, while others cause infection in the lower small intestine, large intestine, and colon. Viruses cause infection by invading healthy cells and converting them into “factories” that produce additional copies of the virus, eventually overwhelming the immune system in severe infections. Viruses are spread through direct contact between infected individuals or through ingestion or contact with contaminated water or foods. 

What are the Health Risks Associated with Enteric Viruses?

Enteric viruses are implicated in thousands of illnesses each year in the United States. About 160 people die from viral diseases spread through contaminated food or drinking water, on average. Enteric viruses infect the digestive system, leading to a wide range of unpleasant and even dangerous symptoms. Symptoms of gastroenteritis (“stomach flu”), or viral infection of the intestines, include:

• Bloating
• Nausea
• Vomiting
• Diarrhea
• Low-grade fever
• Abdominal cramps

Diarrheal illnesses can cause dehydration, especially in young children or elderly individuals. Without medical support, severe dehydration may lead to organ failure and eventual death. Because viruses cannot be controlled by antibiotics, medical professionals treat victims of enteric viral infections with fluids and supportive care. 

How Does Water Become Contaminated with Enteric Viruses?

Water supplies are susceptible to contamination. Whether you get your water from a city source like a municipal water treatment facility or draw your water from your well, contaminants can be present. Common sources of water contamination include:

• Agricultural runoff
• Stormwater runoff
• Severe weather events (flooding/heavy rain)
• Industrial runoff
• Sewage spills or treatment facility discharges
• Animal activity

It is important to remember that enteric viruses are spread through contact with animal or human feces. A leaking septic tank, a sewer system discharge, or contact with feces from an infected individual can all spread the virus to healthy people. If a water treatment system or well is compromised by viral contaminants, users of that water may not know it is contaminated until illness strikes. 

Why Doesn’t my City Filter Water for Viruses?

Municipal water treatment systems collect water from sources like reservoirs, lakes, and rivers and disinfect it with chemicals before piping it to residential and commercial users. Disinfection of water supplies can be very effective in neutralizing many biological contaminants, including bacteria and some viruses.

Unfortunately, viral particles are protected by a durable protein shell that can resist the effects of disinfection agents like chlorine – a chemical typically used in water treatment facilities. If disinfection cannot stop all viruses, why don’t cities filter the water? Water filtration that is effective against viral contamination is complex and highly specialized. Standard home water filters and even many industrial water filtration systems contain filter elements with pores too large to trap viral particles. Only a reverse osmosis water system is effective at stopping viruses from contaminating drinking water, but these systems are too costly to maintain for many municipal water facilities. 

Reverse Osmosis Water Systems to the Rescue

In the home or office, a reverse osmosis water system can stop enteric viruses from causing dangerous illnesses. Reverse osmosis mimics a natural cellular process where fluids pass through a semipermeable membrane. In reverse osmosis, water is pumped under pressure through a membrane equipped with tiny pores. These pores trap contaminants, including viruses, and the clean water passes through. 

How small are the pores in a reverse osmosis water system? To put pore size into perspective, most enteric viruses range from 0.02 to 0.08 microns. A micron is a unit of measurement equaling one-thousandth of a millimeter. A single strand of hair has a thickness of about 70 microns; comparing a hair to the size of typical viral particles, it is easy to see how small they are.  Even though viruses are tiny, requiring high-powered microscopes to spot, the pores in a reverse osmosis system are even smaller. The average pore size in a whole home reverse osmosis water system is 0.0001 micron.

Reverse osmosis water filtration systems are highly effective at removing contaminants, including enteric viruses and:

• Bacteria
• Chromium
• Lead
• Arsenic
• Copper
• Potassium
• Dissolved minerals
• Sulfates

The most advanced reverse osmosis water filtration systems utilize multiple filter stages to remove sediments and suspended solids, improve taste and odor, and increase clarity. With a reverse osmosis water system installed between water supply lines and faucets or fixtures, you can enjoy healthy, safe, and clean water for yourself and your family. This water is used for cooking, bathing, and drinking – essential activities you do every day. Enteric viruses pose a significant health risk – protect your loved ones with clean, pure water by installing a reverse osmosis water system in your home.