The gastroenteritis is an infection of the digestive system that causes nausea, vomiting, abdominal cramps and diarrhea. In the majority of cases, it is short-lived. Symptoms occur quickly and usually resolve after 1 to 3 days.
Gastroenteritis has multiple causes. It can be different viruses , bacteria or other microorganisms (such as amoebae) that are transmitted mainly by hands, water and contaminated food. The intensity and duration of symptoms vary depending on the cause. The viral gastroenteritis are far the most common (more than two thirds of cases).
Many viruses can be involved. In adults, noroviruses (or caliciviruses) are recognized as the agents most often implicated in outbreaks of viral gastroenteritis. The best known of these is the Norwalk virus, first identified in 1968 at a school in Norwalk, United States, during an outbreak of gastroenteritis. As for the rotavirus is the type most frequently guilty of gastroenteritis virus in young children (more than half of cases).
There are also gastroenteritis that are caused by bacteria such as Salmonella, Campylobacter, Shigella, E. coli, Vibrio, Yersinia and Clostridium difficile . Parasites can also be involved such as amoebae, Giardia and Cryptosporidium.
Traveler’s diarrhea can be found in about half of visitors to Asia (excluding Singapore), the African continent (except South Africa), and Central and South America. It is caused by water or contaminated food. Most frequently by the bacteria E Coli, then Salmonella, Campylobacter and Shigella. It occurs 4 to 14 days after arrival. It lasts in general from 1 to 5 days.
It is estimated that about one in five cases of gastroenteritis is caused by bacterial food poisoning. Three mechanisms can be at work:
- Ingestion of food contaminated with a toxin. Some bacteria (Staphylococcus, B Cereus) produce a toxin in foods, before they are consumed. This toxin is heat resistant. The incubation period is 1 to 6 hours and the disease lasts about 24 hours.
- Ingestion of food contaminated by bacteria that produce a toxin once they are rendered in the intestine (C Perfringens, toxigenic E. coli).
- Ingestion of food contaminated with a bacterium that can enter the intestinal wall and cause inflammatory diarrhea (Enterohemorrhagic E Coli, Salmonella, Shigella, Vibrio)
Some antibiotics may cause Clostridium difficile gastroenteritis. This gastroenteritis can be very severe and deadly, especially in the elderly or weakened by a disease. This is one of the reasons why you should not take antibiotics without a valid reason.
Prevalence of Gastroenteritis
Each year, outbreaks of gastroenteritis affect millions of people around the world, especially children. In Canada, as in Europe or the United States, there is an increase in viral gastroenteritis during the winter . Novovirus causes the majority of gastroenteritis outbreaks at any age. It causes severe vomiting and lasts from 12 to 60 hours. As for bacterial gastroenteritis, they occur in any season, but they are much less common than viral gastroenteritis in industrialized countries.
Several studies in Canada have found that, on average, Canadians suffer from 1.3 gastroenteritis per year, of greater or lesser intensity.
According to the studies, it is estimated that 1 in every 200 children aged less than 5 years old is hospitalized each year in developed countries for rotavirus gastroenteritis. In Quebec, 2,000 to 2,500 hospitalizations a year are linked to this disease.
The gastroenteritis contracts by either of the following two ways:
By food poisoning (especially bacterial gastroenteritis). Consumption of food or water contaminated with germs may cause gastroenteritis. Foods that carry the most are, in order of importance, seafood, fruits and unwashed vegetables, poultry, beef and eggs.
By contact with a person or a contaminated object (viral gastroenteritis especially). This is the so-called “oro-fecal” way. You can contract the disease if, after touching a contagious person or contaminated objects or surfaces, you put your hands in the face or prepare a meal without washing your hands well. An infected person is contagious from the moment the symptoms begin and until about 48 hours after their disappearance.
Some foods that can cause food poisoning
- Undercooked ground beef contaminated with E. coli 0157: H7 bacteria. This type of poisoning is called hamburger disease or barbecue syndrome.
- Fresh oysters contaminated with Vibrio vulnificus bacteria .
- Green leafy vegetables contaminated with E. coli 0157: H7. In 2006, nearly 200 people in the United States and Canada were intoxicated after consuming pre-packaged raw spinach contaminated with this bacterium.
- Eggs contaminated with Salmonella bacteria . See our page Salmonellosis.
- Water or food contaminated with Norwalk virus .
- Fruit contaminated with enterotoxigenic E. coli (ETEC) in a country with poor sanitary conditions.
- Poisonous mushrooms.
Hygiene in the food chain
Cows, pigs, poultry, fish and shellfish carry bacteria, viruses and parasites. The hygiene measures and inspections carried out by the agri-food industry make it possible to eliminate a good part of these germs. But the consumer is also a very important link in the chain, because the stages of preparation and cooking of food also help eliminate germs. Refreezing a thawed product or breaking the cold chain at either stage may, for example, cause the growth of harmful microorganisms.
Although generally benign in industrialized countries, gastroenteritis is often fatal in many parts of the world (1.5 to 2.5 million deaths per year from acute diarrhea 11 ). In particular, rotavirus is particularly severe, very often causes dehydration. It particularly affects young children and causes 500,000 deaths a year in the world. If not properly managed, it can have serious consequences for people of fragile constitution (eg infants, young children, sick or elderly) due to the dehydration it causes.
Dehydration occurs when the body loses too much fluid and mineral salts, essential to the functioning of the body. A child can become severely dehydrated after only 1 or 2 days of diarrhea .
It should be noted that in very rare cases, serious intoxications, particularly E. coli toxin infections, can cause kidney damage . These intoxications begin with common symptoms of gastroenteritis – such as diarrhea – but can degenerate and lead to death. Gastroenteritis (colitis) with Difficult C can also be very serious and is sometimes fatal.
When to consult?
A doctor should be consulted as soon as possible if any of the following symptoms occur.
In the infant:
- Signs of dehydration : Severe thirst and dry layers, eyes darkened and “sunken” into the eye socket, dry mouth, lack of tears, fontanels more pronounced than usual.
- Blood in the stool, which can be red or black.
- Lethargy or excessive sleep (it is difficult to wake the baby).
- Vomiting for several hours.
- A fever above 38.5 ° C (101.3 ° F).
- A fast breathing, panting.
|Note. Diarrhea and vomiting can affect the absorption of medications, which can make them less effective. This is also the case for the contraceptive pill. When in doubt, consult a doctor.|
- Vomiting or diarrhea that leads to symptoms of dehydration and cannot be counteracted with rehydration solution (see below).
- Inability to urinate for more than 12 hours.
- Vomit blood or have blood in the stool.
- Strong abdominal pain lasting more than 2 hours.
- A fever of 40 ° C (104 ° F) or more.
Symptoms of gastroenteritis
In healthy adults , the symptoms of gastroenteritis usually last from 1 to 3 days. Exceptionally, they can persist for up to 7 days. The intensity of the symptoms varies according to the cause, the bacterial gastroenteritis being more serious than the viral gastroenteritis.
Symptoms of gastroenteritis
- A loss of appetite.
- Abdominal cramps.
- Nausea and vomiting that appear suddenly.
- A very watery diarrhea.
- A slight fever (38 ° C or 101 ° F).
Signs of dehydration
- Dryness of the mouth and skin
- Feelings of urination less frequent and urine darker than usual.
- Muscle cramps
- A loss of weight and appetite.
- A weakness.
- Hollow eyes.
- A state of shock and fainting.
People at risk
- The young children (6 months to 3 years), especially those who attend day care centers or kindergartens due to increased contact. They are particularly at risk because their immune system is immature and they carry everything to their mouths. On average, a child under 5 years suffer from diarrhea 2.2 times per year in industrialized countries . The daycare staff is therefore also more at risk.
- Older people , especially those who live in residence, because their immune system weakens with age.
- People who live or work in a closed environment (hospital, airplane, cruise, holiday camp, etc.). Half of them are likely to contract gastroenteritis when an epidemic breaks out.
- People traveling to Latin America, Africa and Asia.
- People with immune systems weakened by disease or immunosuppressive drugs , such as anti-rejection drugs for transplant patients, certain anti-arthritic drugs, cortisone or powerful antibiotics that upset the intestinal flora.
Do not follow the hygiene measures described in the section Prevention of gastroenteritis .
Prevention of gastroenteritis
|Basic preventive measures|
To prevent person-to-person contamination
To prevent food poisoning
To prevent gastroenteritis in young children
In children, rotavirus infections are almost inevitable, especially if the child is kept in the community. By the age of 5, more than 95% of children will have been infected with this virus at least once.
However, since 2006, a vaccine against rotavirus gastroenteritis has been available for infants from 6 weeks of age. Vaccination consists of 2 or 3 doses administered orally with an interval of at least 1 month between doses. Talk to a doctor.
|Measures to prevent complications|
|You have to rehydrate to replace the lost fluids.
Seek medical attention if worrying signs occur (see When to Consult?).
Medical treatments of gastroenteritis
Most people recover within 1 to 3 days. The goal of the treatment is to rehydrate and prevent dehydration .
The isolation of the sick person is desirable. It is better to stay at home and rest.
- First, when there is vomiting , wait a few hours after they have stopped before drinking or eating to allow the digestive system to recover. However, young people may try to drink a rehydration solution when they have spent 30 minutes without vomiting.
- Then take small sips of water or rehydration solution. It is found in pharmacies (Gastrolyte). You can make it yourself, which is less recommended (see recipes below). Avoid consuming too much in one go. At first, it is advisable to take about 1 tbsp. of solution every 10 minutes, then increase gradually.
- If vomiting continues, wait 30 minutes and then try to absorb some water or rehydration solution.
- Avoid alcohol, which dehydrates and irritates the digestive system. Avoid also drinking several glasses of soft drinks a day (especially cola). Their high sugar content can make diarrhea worse .
Mix 360 ml unsweetened orange juice with 600 ml cooled boiled water, 1/2 tsp. table salt.
|Mode of conservation. The solutions are stored for 12 hours at room temperature and 24 hours in the refrigerator.
Beware of errors! An error (eg the amount of salt) during the preparation of the solution can lead to serious complications. For this reason, most experts recommend using a commercial solution such as Pedialyte or Gastrolyte, especially in children.
Avoid: Soft drinks like 7-up, even degasified, sugary or undiluted drinks or fruit juice.
Often offer to drink an electrolyte rehydration solution to the child (on sale in a pharmacy). Suggest the solution, preferably fresh, several times an hour, in small sips or with a spoon. We start with as little as 5 to 15 ml at a time. In the baby from 0 to 6 months, from 30 to 90 ml per hour, from 6 months to 2 years 90 to 120 ml per hour, and for two years and more from 125 to 250 ml per hour. If the child starts vomiting again, give a break of 30 to 60 minutes and start again from the beginning (5-15 ml at a time).
As long as the discomfort persists, it is better to avoid consuming the following foods, which aggravate cramps and diarrhea:
- dairy products;
- citrus juices;
- the meat;
- spicy dishes;
- the sweets;
- foods high in fat (including fried foods);
- foods that contain wheat flour (bread, pasta, pizza, etc.);
- corn and bran, which are high in fiber;
- fruits, with the exception of bananas, which would be rather beneficial, even in young children from 5 months to 12 months;
- raw vegetables.
Once the nausea is gone, gradually reintroduce a solid diet by favoring certain foods easier to digest. The starchy foods like white rice, unsweetened cereals, white bread and crackers, are usually well tolerated and reduces diarrhea. Stop eating if symptoms return. Then gradually add fruits and vegetables, yogurt, then protein foods (lean meat, fish, eggs, cheese, etc.).
If necessary, taking acetaminophen (Acet, Tylenol, and Tempra) can relieve stomach pain.
To “block” diarrhea, especially during travel, antidiarrheal medications such as loperamide (eg Imodium, Diar-Ezee) or diphenoxylate hydrochloride (Lomotil) can be used. However, they do not treat the infection and should be avoided as much as possible. They are contraindicated in the presence of high fever or blood in the stool.
In more severe cases, hospitalization may be necessary. Doctors then use an intravenous infusion to rehydrate the body. Antibiotics are prescribed as needed to treat severe bacterial gastroenteritis.