Though AGIs occur year around, they are often associated with food- and water-borne germs during the summer months. The cause may be traced to one's own back yard, a local food source, or recreational activity. While the specific type of bug, or germ, that causes an AGI may not always be known, both the symptoms and the way to minimize the risk of getting sick are often the same.
Symptoms can last a day to over a week depending on the causal organism. Most of the time, AGIs get better without treatment, but in certain people with weakened immune systems and in young children, the illness can become severe enough to require hospitalization or result in death. But even in healthy adults, an AGI can impair a person's ability to work and perform physical tasks. It can take days before symptoms improve and a patient often needs time to rest for full recovery. Additionally, the dehydration and diarrhea associated with AGIs can increase the risk of heat illness in hot environments.
Military Impacts
AGIs have long been a significant cause of illness among U.S. service
members
who have been found to be less likely to seek medical treatment than civilians. AGI outbreaks in the military have resulted in temporary suspension of training, quarantining to barracks, efforts to disinfect barracks floors, and increased inspections of military eating establishments.
The most frequently diagnosed diarrheal food- and water-borne AGI disease in the military population is Norovirus, also referred to as the
Norwalk virus. According to the
Medical Surveillance Monthly Report (MSMR), the next most common diseases in the military reported in 2024 were
Campylobacteriosis, Salmonella,
Giardia,
E.coli,
Cryptosporidiosis, and
Shigella. Less common diseases in the U.S. military, like
Amebiasis and
Hepatitis A, or, more rarely, Botulism, Cholera, Listeriosis, and Typhoid Fever, are often associated with exposures overseas.
The DHA Disease Reporting Surveillance internet (DRSi) is used to help identify possible outbreaks before they can impact military readiness. To know the actual disease name, a patient must seek medical evaluation that includes laboratory testing to identify the specific type of virus, bacteria, or parasite. Identified diseases are reportable medical events (RMEs) in DRSi. Summaries of cases are reported in the
MSMR. Since many cases of AGI are not diagnosed with the specific diseases, however, the number of reported cases is much lower than the number of service members infected.
Specific case definition and reporting guidance for military medical facilities personnel are provided in the
Communicable Disease Toolkit (CDT).
The organisms that cause AGIs may last hours to days on surfaces and may live weeks, months, or even years in some environments.
Variations include time of symptom onset and duration of symptoms. Most are treated for the symptoms only, though for some antibiotics may also be used. Additional details on specific diseases are listed further below.
Prevention Tips
AGIs are largely all preventable by practicing good hygiene, cooking food thoroughly, consuming food and water from approved sources, and avoiding contact with contaminated sources. Specific tips:
- Keep your hands clean – always!
-
Wash hands with soap and water for at least 20 seconds often, especially –
- After contacting food, animals, other people who may be sick (or their clothing or linens they use)
- Before and after handling or touching food, utensils, or surfaces
- Use gloves to avoid contacting potential germs
- Clean
and disinfect:
- Areas where a person or pet recently had diarrhea or vomit
- Potentially contaminated food utensils or surfaces (such as in contact with raw meat or unwashed produce)
- Cook meats and shellfish thoroughly. In general, processed meat like hamburgers should be well-done with no pink showing, but since meat can brown before it's completely cooked (especially with outdoor grilling), it's best to use a meat thermometer to ensure that it reaches a safe internal temperature for the type of meat you're cooking (e.g., most ground meats need to be heated to at least 160 F (71 C) at its thickest point).
- Avoid drinking unpasteurized milk, juice or cider
- Wash fruits and vegetables
- Wash laundry in hot water
- Avoid swallowing water while swimming
-
Boil or filter water from lakes, springs, or rivers before drinking or using to prepare food
__________________________________________________________________
Common Food- and Waterborne Illnesses
NOROVIRUS INFECTION (Norwalk virus)
- Sources:
- Ingesting contaminated food or liquids
- High risk:
- Raw or undercooked shellfish
- Putting unwashed fingers in mouth after contact with contaminated person/items
- Symptoms:
- Diarrhea, vomiting, nausea, stomach pain; possible fever, headache, and body aches
- Begin 12 to 48 hours after becoming infected
- Last 1 to 3 days
- Notes:
- The most common cause of diarrhea and vomiting in U.S.; most cases not reported as do not require medical treatment
- Sometimes called the "stomach flu" or the "stomach bug" (though is not related to the flu)
- Very contagious between people, highest risk during symptoms (vomiting) and up to a few days after symptoms, but virus may be shed two weeks after symptoms end
CAMPYLOBACTERIOSIS (Campylobacter bacteria)
- Sources:
- Ingesting contaminated food or liquids.
- High risk:
- Raw or undercooked poultry seafood, meat
- Unwashed produce (salads, fruits, vegetables)
- Cutting boards and knives used to prepare contaminated food
- Untreated contaminated water
- Putting unwashed fingers in mouth after contact with contaminated person/items
- Animal sources
- Symptoms:
- Diarrhea, stomach cramping, vomiting, and fever
- Can begin 2 to 5 days after becoming infected
- Can last 7 days
- Notes:
- Most common in the summer
- Can live in the intestines, liver, and other organs of chickens, cows, and other animals that are not sick
- Animal sources e.g., food, water, excrement, toys, bowls, or habitats (beds, cages, tanks, coops, stalls, and barns)
SALMONELLOSIS (Salmonella bacteria)
- Sources:
- Ingesting contaminated food or liquids
- High risk:
- Raw or undercooked meat, poultry, and eggs or egg product
- Unpasteurized milk
- Putting unwashed fingers in mouth after contact with contaminated person/items
- Animal sources
- Symptoms:
- Diarrhea, fever, and abdominal cramps
- Can begin 6 hours to 6 days after exposure; most common 8 hours to 3 days
- Can last a few days to a week
-
Notes:
- People who have salmonella infection often think they have 'stomach flu'
- Treatment may include hydration and in severe cases antibiotics
GIARDIASIS (Giardia parasite)
- Sources:
- Ingesting contaminated water source
- High risk:
- Lakes/streams/river (untreated water)
- Putting unwashed fingers in mouth after contact with contaminated person/items, soil
- Symptoms:
- Diarrhea (2-5 times a day), gas, smelly greasy poop that can float, stomach cramps/ pain/nausea, dehydration, fatigue
- Can begin 1 to 2 weeks after becoming infected
- Can last 2 to 6 weeks
- Notes:
- In the U.S. more people get sick from Giardia than any parasite living in the gut
- Giardia is found in every region of the U.S. and around the world
- Can survive for weeks to months outside the body (for example, in soil)
ESCHERICHIA COLI (Shiga toxin producing e. coli, STEC)
-
Sources:
- Ingesting contaminated food or liquids
- High risk:
- Undercooked meats
- Unsanitized drinking water, lakes, streams, rivers, swimming pools
- Unpasteurized dairy, cider, juice drinks
- Unwashed raw fruits and veggies
- Putting unwashed fingers in mouth after contact with contaminated person/items
- Symptoms:
- Diarrhea can be bloody or watery, stomach cramps can be severe; possible vomiting or fever, blood in urine, hemolytic uremic syndrome (HUS)
- Can begin 3 to 4 days after becoming infected
- Can last 5 to 10 days
- Notes:
- There are many forms of E. coli bacteria – most are harmless and part of a healthy intestinal tract to help digest food, produce vitamins, and protect from harmful germs, but some E. coli can make people sick, including STEC.
- HUS is a medical emergency. Signs include little or no peeing, losing pink color in cheeks, unexplained bruising or rash of tiny red spots, blood in pee, and extreme fatigue; can lead to kidney failure, permanent health problems, and even death.
CRYPTOSPORIDIOSIS (Cryptosporidium parasite)
- Sources:
- Ingesting contaminated food, liquids, soil
- High risk:
- Swimming pools, unsanitized drinking water, lakes, streams, rivers
- Unpasteurized dairy, cider, juice drinks
- Unwashed raw fruits and veggies
- Putting unwashed fingers in mouth after contact with contaminated person/items
- Symptoms:
- Watery diarrhea, stomach cramps, nausea, and dehydration
- Can begin 2 to10 days after infection
- Can last 1 to 2 weeks
- Notes:
- Outbreaks often linked to swimming pools, unpasteurized beverages, and childcare settings
SHIGELLOSIS (SHIGELLA) (Shigella bacteria)
- Sources:
- Ingesting contaminated food, liquids, soil
- High risk:
- Putting unwashed fingers in mouth after contact with contaminated person/items
- Sexual activity
- Childcare/diapers
- Symptoms:
- Diarrhea can be bloody or prolonged (lasting more than 3 days), fever, stomach pain, feeling need to pass stool even when bowels are empty
- Can begin 1 to 2 days after infection
- Can last 7 days
- Notes:
- Despite treatment with antibiotics, some strains are now antibiotic resistant
Additional Resources
