Diarrhoea and vomiting as a result of a gastrointestinal infection

The causative agents of gastrointestinal infections can be viruses, bacteria or parasites, which are identified by microbiological tests.  Outbreaks of viral diarrhoea in collectives in particular, and the continued carriage (germ-carriage) of pathogens after illness, are characteristic.

The cause

Gastrointestinal infections are caused by different pathogens (viruses, bacteria, fungi and parasites). The most common pathogens are noroviruses, rotaviruses and adenoviruses. Of the pathogenic intestinal bacteria, the most common are Campylobacter, Salmonella, and pathogenic strains of E. coli. Poisoning by Staphylococcus aureus is also common. Infection with parasites is less common.

Incubation period

The time from infection to the first signs of illness usually lasts from a few hours to a few days, but can be longer depending on the causative agent and the infectious dose (the amount of disease-causing microbes) a person receives.

Transmission

The causative agents of gastrointestinal infections are ingested through food, water or by carrying them in the mouth with dirty hands. The germs are thus excreted in the stool of the person affected for some time. Once the patient recovers, the secretion of microbes usually does not stop, but continues for several days to months. The agent is released back into the environment from the patient or germ-carrier, and in unhygienic conditions the infection can easily spread to healthy persons. Some pathogens can also infect animals that show no signs of disease but can transmit the pathogens to humans.

The infective dose of intestinal viral infections is low, unlike most bacterial infections. A small amount of viruses is therefore required for infection. Outbreaks of e.g. norovirus diarrhoea can make whole groups of children in kindergartens, nursing home residents, family members, etc. ill.

Susceptibility for infection

People of all ages are susceptible to infection. The disease can be dangerous for young children, the elderly, chronic patients and pregnant women.

Symptoms of the disease

Digestive problems are caused by inflammation of the gastrointestinal tract. They are manifested as nausea, vomiting, abdominal cramps, diarrhoea, fever. The patient becomes rapidly exhausted by the disease and is at risk of dehydration due to fluid loss. In mild infections, the disease is milder, or there may be no signs of disease at all.

Infectiousness

The patient or germ-carrier is infectious as long as they excrete the pathogens in the faeces.

Treatment

Treatment of gastrointestinal infections depends on the type of causative agent and the patient’s problems. Most of the time, the problem is alleviated, and only in exceptional cases are we treated with antibiotics. The most important thing is to replace lost fluid and salt. We must ensure that the patient consumes at least 2 to 3 litres of fluid per day, plus any fluid lost due to illness or diarrhoea, vomiting and sweating. If the problems are more severe and fluid replacement by drinking is not possible, a doctor should be consulted or treatment with infusions should be given in a hospital.

Disease prevention

General preventive measures

The most important factors in preventing the occurrence and spread of gastrointestinal infections are general hygiene measures and the choice of safe food and drinks.

Hand washing:

• In general, we should wash our hands as often as possible, or when we are “moving from less clean to more clean tasks”. Always wash your hands thoroughly with soap and clean water, especially after using the toilet.
• Before eating, wash your hands thoroughly with clean water and soap.
• Where clean water is not available, we advise the use of wet wipes or alcohol wipes.

Food:

• Eat well-baked/cooked food that has just been prepared.
• Eat fruit and vegetables that we can peel by ourselves.
• Follow the rule: “Cook, bake, peel or don’t eat”!
• Persons with gastrointestinal infections should not work in the production, transport and sale of foodstuffs, in the supply of drinking water to the population, or in the care and feeding of young children.

Water:

• Drink bottled drinks (originally sealed) and do not add ice, or drink boiled water or fermented drinks.
• In unregulated environments, we should also brush our teeth with bottled or boiled water.

Specific preventive measures

• Hepatitis A vaccination;
• Typhoid vaccination;
• Vaccination against rotavirus infections.