Food & Waterborne Diseases


Exposure to various pathogens in food and water have the potential to cause diarrheal disease. Air and water temperatures, precipitation patterns, and variations in our seasons all affect transmission of food and waterborne diseases. Although anyone can contract food and waterborne diseases, children and older adults are most vulnerable to serious illness from these diseases. Although cases of these diseases are not typically increasing in the United States (U.S.), they continue to remain a concern as they are a major public health problem in developing countries. 

Food & Waterborne Diseases Data Overview

Check out the points below for the main takeaways from this page. 

• According to the CDC, each year 31 major pathogens acquired in the U.S. cause about 9.4 million episodes of foodborne illness, 55,961 hospitalizations, and 1,351 deaths.

• According to the CDC Division of Viral Disease, norovirus is the cause of 58% of all foodborne illnesses acquired in the U.S.

• In 2019, there were 172 cases of salmonella, 20 cases of shigella, and 37 cases of E. coli in NH. 

• Campylobacter cases in NH increased 40% between 2014 (216 cases) and 2019 (302 cases). 

• In 2018, legionella cases spiked to 76 total cases in the state.  At least 34 of those cases were associated with an outbreak in Hampton, NH. 


What is Campylobacter?

Campylobacter infection, or campylobacteriosis, is caused by Campylobacter bacteria. Campylobacter infection is contracted by eating raw or undercooked poultry or eating something that touched raw or undercooked poultry. It can also be caused by eating foods such as seafood, meat, and produce, by having contact with animals, and by drinking untreated water. Most people with Campylobacter infection usually recover on their own, but some require treatment by antibiotic. 

Campylobacter Data Snapshot

Campylobacter causes an estimated 1.5 million illnesses each year in the U.S. The CDC estimates Campylobacter is the number one cause of bacterial diarrheal illness in the U.S. and the number one intestinal disease diagnosed in travelers returning to the U.S.

Cryptosporidium & Giardia

Cryptospordium and Giardia are microscopic parasites that cause diarrheal diseases. These parasites can be found all over the U.S. and throughout the world.  The most common way to contract these parasites is by drinking water or using ice made from untreated or improperly treated water sources such as lakes, streams, river, or wells, or from swallowing water while swimming or playing in lakes, rivers, springs, ponds, and streams. These parasites are protected by an outer shell that allows it them to survive outside the body for long periods of time and makes them very tolerant to chlorine disinfection. Children in childcare settings, especially diaper-aged children, and hikers, campers, and individuals drinking or swimming in untreated water sources are at highest risk for contracting these parasites.

What is Cryptosporidium?

Cryptosporidium causes Cryptosporidiosis. Both the parasite and the disease are commonly known as Crypto. Symptoms generally begin two to 10 days after becoming infected with the parasite and include watery diarrhea, stomach cramps or pain, dehydration, nausea, vomiting, fever, and weight loss.

What is Giardia?

Giardia causes Giardiasis. Giardia is found on surfaces or in soil, food, or water that has been contaminated with feces from infected humans or animals. Symptoms include diarrhea, gas or flatulence, greasy stool that can float, stomach or abdominal cramps, upset stomach or nausea, and dehydration.

Cryptospordium Data Snapshot

Cryptosporidium is a leading cause of waterborne disease among humans in the United States (CDC), with an estimated 748k cases of cryptosporidiosis occurring annually.

Giardia Data Snapshot

Giardia infection (Giardiasis) is also a leading cause waterborne disease in the U.S. Transmission of Giardiasis occurs throughout the U.S., with more frequent diagnosis occurring in northern states. According to the CDC, the U.S. saw a total of 15,223 cases in 2012, a decrease for the first time since 2002.

Hepatitis A

Hepatitis A is a highly contagious liver infection caused by the hepatitis A virus (HAV). It can range from mild illness lasting a few weeks to severe illness lasting several months. Although rare, hepatitis A can cause death in some people. Hepatitis A usually spreads when a person unknowingly ingests the virus from objects, food, or drinks contaminated by small, undetected amounts of stool from an infected person. To learn more, visit our Viral Hepatitis page.

Hepatitis A Data Snapshot

Hepatitis A is one of the five main foodborne illnesses in the U.S. In 2018 and 2019, NH and other states experienced an outbreak of Hepatitis A. In NH, the highest burden of disease was in people experiencing homelessness and people with substance use disorder. Although this outbreak was not directly related to foodborne illness, transmission of HAV from contaminated food is a common route of a transmission.

Legionella & Listeria

Although most healthy people will not get sick if infected with these types of bacteria, people at most risk for illness include older adults and people with weakened immune systems. 

What is Legionella?

Legionella bacteria can cause a serious type of pneumonia called Legionnaires’ disease, and a less serious illness called Pontiac fever. Legionella is found naturally in freshwater environments, but becomes a health concern when it grows and spreads in human-made building water systems, such as shower heads, sink faucets, cooling towers, hot tubs, decorative water features, hot water tanks and heaters, and plumbing systems. People can get Legionnaires’ disease if they breathe in small droplets of water that contain Legionella. Symptoms include cough, muscle aches, fever, shortness of breath, and headache. 

What is Listeria?

Listeria bacteria can cause a serious infection known as Listerosis. People usually become ill with Listeriosis after eating contaminated food. Listeriosis can cause a variety of symptoms, depending on the person and body part affected. People with Listeriosis usually report symptoms one to four weeks after eating contaminated food. This disease mostly affects pregnant women and newborns. When Listeriosis occurs during pregnancy, it can cause miscarriage, stillbirth, or newborn death. Most people with invasive Listerosis require hospital care, and about one in five die.

Legionella Data Snapshot

According to the CDC, cases of Legionnaires' Disease have been increasing since 2000. In 2018, there was approximately 10k cases reported in the U.S., although that number is believed to be under-diagnosed. 

Listeria Data Snapshot

Approximately 1.6k people in the U.S. get Listeriosis each year and about 260 die (CDC). Listeriosis during pregnancy results in loss of the fetus in about 20% of cases and newborn death in about 3% of cases (CDC).

Hampton Legionella Outbreak

Outbreaks are commonly associated with buildings or structures that have complex water systems, such as hotels, long-term care facilities, hospitals, and cruise ships. In 2018, there was an outbreak of Legionnaires' disease in Hampton, NH. At least 34 individuals likely acquired their illness through the hot tub or potable water system at the Sands Resort in Hampton. For more information about the Hampton Legionella outbreak, visit the NH DHHS webpage


Norovirus, also known as the stomach bug, is a contagious virus causing excessive vomiting and diarrhea. Norovirus spreads very easily and can be contracted from having direct contact with an infected person, consuming contaminated food or water, or touching contaminated surfaces then putting your unwashed hands in your mouth. If you contract norovirus, you can become re-infected later on. Our bodies do not build immunity to this virus and we can become re-infected with it as many times as we come into contact with the virus.  Outbreaks can happen anytime, but occur most often from November to April. There is currently no vaccine to prevent norovirus, the best way to keep yourself healthy is proper hand washing.

Norovirus Data Snapshot

Norovirus is the leading cause of foodborne illness in the U.S. and accounts for 19 to 21 million cases of diarrheal and vomiting illnesses each year, according to the CDC. Norovirus is the cause of 58% of all foodborne illnesses acquired in the U.S., with infected food workers causing about 70% of reported norovirus outbreaks from contaminated food.

CDC Division of Viral Diseases

Salmonella, Shigella, & E. coli

Salmonella, Shigella, and E. coli are enteropathogenic, meaning they have the ability to cause disease of the intestinal tract. When infected, some people will not develop symptoms for several days, or ever, but they can still pass the bacteria to others. Proper and frequent handwashing with soap and running water is the best way to prevent the spread of these bacteria.


Salmonella are bacteria that make people sick. They live in the intestines of humans and animals, and people can get infected by eating contaminated food, drinking contaminated water, or touching infected animals, their feces, or their environment. Symptoms include diarrhea, fever, and stomach cramps. While most people fully recover, some people’s bowel habits may not return to normal for a few months. 


Shigella is a group of bacteria causing an infectious disease known as Shigellosis. It is contracted by coming into contact with an infected person's stool and touching your mouth with unwashed hands. Most people infected with Shigella have fever, diarrhea, and stomach cramps, usually lasting five to seven days. People with Shigellosis have Shigella germs in their stool for up to two weeks after symptoms.

E. coli

Escherichia coli (E. coli) are bacteria found in the environment, food, and intestines of humans and animals. Most strains are harmless, but some make you sick, including STEC (shiga toxin producing E. coli). Some E. coli bacteria cause diarrhea. Others cause urinary tract infections and respiratory illness. Some people with STEC develop potentially life-threatening complications.

Salmonella, Shigella, & E. coli Data Snapshot

Salmonella bacteria cause approximately 1.35 million infections, 26.5k hospitalizations, and 420 deaths in the U.S. each year (CDC). Shigella bacteria cause about 450k cases of diarrhea annually (CDC)The most common E. coli bacteria, STEC infections, cause about 265k cases per year (CDC).  


Proper Handwashing

Handwashing is critical in reducing the spread of most foodborne diseases. According to the CDC, handwashing with soap could protect about 1 out of every 3 young children who get sick with diarrhea.

Health Equity & Food & Waterborne Diseases

A person's health can be seriously impacted by their race, ethnicity, gender, income level, education, and other socioeconomic factors. In regards to food and waterborne diseases...

• While foodborne illness is not traditionally tracked by race, ethnicity, or income, analyses of reported cases have found increased rates of some foodborne illnesses among minority racial/ethnic populations (Foodborne illness incidence rates and food safety risks for populations of low socioeconomic status and minority race/ethnicity).

Click the buttons below to explore other pages related to Food and Waterborne Diseases

Do you have questions or comments about the information on this site? Contact us

Looking for resources in Greater Nashua? Get Connected. Get Help. Visit or dial 2-1-1.