Infectious gastroenteritis can be caused by a wide variety of pathogens [guidelines: jS2k guideline]:
| Bacteria | Viruses | Toxin formers | Protozoa | Helminths (worms) |
| Escherichia coli (EC/E. coli) | Rotaviruses | Staphylococcus aureus | Giardia lamblia | Plathelminthes |
| – Enterotoxin-producing EC (ETEC). | Adenoviruses | Bacillus cereus | Cryptosporidium parvum | – Trematodes |
| – Enteroinvasive EC (EIEC). | Noroviruses* | Clostridium perfringens | Entamoeba histolytica | – Schistosoma |
| – Enterohemorrhagic EC (EHEC) | Sapoviruses | – | Cyclospora cayetanensis | – Cestodes |
| – Enteropathogenic EC (EPEC) | Influenza, coxsackie, and echoviruses (rare) | – | Isospora belli | Trichinella |
| – Enteroaggregative EC (EAEC). | – | – | – | Strongyloides stercoralis |
| Yersinia enterocolitica | – | – | – | – |
| Yersinia pseudotuberculosis | – | – | – | – |
| Clostridium difficile (toxin producer* * ) | – | – | – | – |
| Campylobacter jejuni | – | – | – | – |
| Campylobacter coli | – | – | – | – |
| Listeria | – | – | – | – |
| Salmonella | – | – | – | – |
| Shigella | – | – | – | – |
| Vibrio cholerae | – | – | – | – |
* The type species of the genus Norovirus (belonging to the calicivirus group), Norwalk virus, was first characterized morphologically in stool specimens from a 1968 viral gastroenteritis outbreak in Norwalk, Ohio in 1972. The disease was given the name “winter vomiting disease” because of its characteristic symptomatology of gushing vomiting and its predominantly seasonal occurrence in the winter months. * * Other toxin producers are: Staphylococcus aureus and Bacillus cereus.
Bacterial enteritis
Bacteria cause about 30 percent of diarrheal illnesses in adults. Possible pathogens include Escherichia coli or E. coli, Campylobacter jejuni, streptococci, and staphylococci. Campylobacter jejuni is transmitted to humans primarily through animal foods (poultry, raw milk) and pets. E. coli is transmitted by smear infection and primarily through contaminated food. Direct or indirect detection of Campylobacter sp., intestinal pathogen is reportable according to the Infection Protection Act (IfSG), as far as the evidence indicates an acute infection. For example, a number of intestinal pathogenic E. coli strains are known, including the so-called ETEC = enterotoxic, EHEC = enterohemorrhagic, EIEC = enteroinvasive and EPEC = enteropathogenic E. coli strains. Enterohemorrhagic colitis is caused by EHEC. Transmission is fecal-oral (ingestion of the pathogen through contact with animal feces, contaminated food, or contaminated water). Ruminants (e.g., cattle) are considered the germ reservoir. EHEC is usually ingested via contaminated food. Infection from person to person (smear infection) is also conceivable. The incubation period (time that elapses between infection with a pathogen and the appearance of the first symptoms) of EHEC infection is approximately 2 to 10 days (on average: 3-4 days). The infection may be clinically inapparent; in the majority of cases, symptoms include nonbloody, usually watery diarrhea associated with accompanying symptoms such as nausea (nausea), vomiting, and increasing abdominal pain (abdominal pain), rarely with fever. In 10-20% of cases, this develops into a severe course with hemorrhagic colitis (intestinal inflammation with bloody stool). This is accompanied by cramping abdominal pain, bloody stools and sometimes fever.In 5-10 % of infected persons – especially children and the elderly – a hemolytic uremic syndrome (HUS) is triggered, which is accompanied by hemolytic anemia (anemia due to the disintegration of red blood cells), thrombocytopenia (deficiency of blood platelets) and renal insufficiency (under-functioning of the kidneys). Neurological symptoms (e.g., epilepsy) also occur in up to 40% of cases. Acute kidney failure (ANV) is particularly common in children. The lethality (mortality, i.e. the ratio of deaths to the number of patients) of HUS is approximately 2 %. ETEC (enterotoxic E. coli) are responsible for the so-called travel diarrhea.
Caused by salmonella or shigella
Salmonella enteritis (salmonellosis) is attempted by enteritis salmonella, for example, Salmonella enterica subsp. enterica serovar Enteritidis (short name Salmonella Enteritidis) and Salmonella Typhimurium. Diarrhea (diarrhea) is the primary symptom. In addition, abdominal pain, nausea (nausea), vomiting and fever are possible. Salmonella is transmitted via unclean drinking water or the consumption of contaminated food. In this case, infected meat (poultry, pigs, cattle, but also reptiles) – especially poultry – raw milk, eggs and egg dishes can be the carriers of salmonella. The incubation period ranges from a few hours (12-72 hours) to three, maximum seven days. In most cases, the symptoms subside quickly (they usually last only a few hours or days). However, systemic symptoms such as fever, fluid loss and weight loss develop in approximately five percent of patients, necessitating hospitalization. Direct detection of “Salmonella Typhi/Salmonella Paratyphi” is notifiable under the Infection Protection Act. Direct or indirect detection of “Salmonella, other” is reportable under the Infection Protection Act if the evidence indicates an acute infection. Shigella enteritis (shigellosis) is a diarrheal disease that is common worldwide and is caused by bacteria of the genus Shigella. Shigella is transmitted fecal-orally, predominantly by direct person-to-person contact. Even a minimal ingested germ dose – 10-200 germs – can cause clinical symptoms. The incubation period is 2 to 7 days. The disease is accompanied by watery to bloody diarrhea (diarrhea), abdominal cramps, and fever. The infection shows a clustering in warm months, with children being particularly affected. Direct or indirect detection of “Shigella sp.” is reportable under the Infection Protection Act, as long as the evidence indicates an acute infection.
Caused by vibrions
Cholera disease is caused by vibrios, with the Vibrio cholerae El Tor biotype being the main germ. It is an enterotoxic, potentially life-threatening small intestinal disease with severe diarrhea, vomiting, muscle cramps, and shock. Transmission is fecal-oral via fecally contaminated water – e.g., during floods and poor sanitation – seafood, fish, and other foods eaten raw. The incubation period is usually only three to six days. Direct or indirect detection of “Vibrio cholerae O 1 and O 139” is reportable under the Infection Protection Act, provided that the evidence indicates acute infection.
Pseudomembranous enterocolitis/pseudomembranous colitis (Clostridia)
This form of enteritis (inflammation of the intestine) can result from the intestinal flora being so severely damaged by antibiotics that it can lead to an excessive proliferation of Clostridium difficile (anaerobic spore-forming Gram-positive bacterium), which is usually part of the healthy intestinal flora. Clostridium difficile bacteria partly possess the ability to produce toxins (enterotoxin A, cytotoxin B and binary toxin). These can lead to enteritis. Clostridium difficile is now the leading cause of nosocomial diarrhea (hospital-acquired diarrheal illness). Since Clostridium difficile is resistant to almost all broad-spectrum antibiotics, antibiotic therapy can cause this germ to multiply. Affected patients suffer from fever up to 40 °C, bloody-mucous diarrhea and abdominal pain (abdominal pain).
Conditioned by yersinia
Yersinia – particularly Yersinia enterocolitica – causes this enteritis (enteric yersiniosis) transmitted through animal contact and contaminated animal foods. In rare cases, transmission can occur directly via infected person. This pathogen is detectable in only about one percent of all diarrheal cases. The incubation period averages 2-7 days (minimum: 1 day; maximum: 11 days). The clinical picture of Yersinia enterocolitica includes diarrhea (diarrhea), followed by reactive arthritis (joint inflammation) or inflammation of the subcutaneous fat tissue (erythema nodosum (synonyms: Nodular erythema, dermatitis contusiformis, erythema contusiforme; plural: erythema nodosa; granulomatous inflammation of the subcutis (subcutaneous fatty tissue), also known as panniculitis, and a painful nodule (red to blue-red color; later brownish). The overlying skin is reddened. Localization: both extensor sides of the lower leg, on the knee and ankle joints; less frequently on the arms or buttocks) may occur. Infection with Yersinia pseudotuberculosis resembles appendicitis (inflammation of the appendix); symptoms reminiscent of Crohn’s disease or ulcerative colitis may also occur. Direct or indirect detection of “Yersinia enterocolitica, intestinal pathogen” is reportable under the Infection Protection Act if the evidence indicates an acute infection.
Viral enteritis
In 2002, Norwalk viruses were renamed noroviruses. Currently, norovirus infections are believed to be the most common cause of acute gastroenteritis (gastrointestinal infections) in children and adults. In recent years, for example, this notifiable infectious disease has frequently broken out on cruise ships, in hospitals, and in nursing homes. An incidence peak occurs in the winter and spring months, as the main route of transmission of noroviruses is aerogenic – via the air – and many other aerogenically virus-transmissible diseases – e.g. influenza – also have the highest incidences (frequency of new cases) during the cold season. Transmission occurs fecal-orally (e.g., hand contact with contaminated surfaces) or by oral ingestion of virus-containing droplets produced during vomiting. The incubation period (time that elapses between infection with a pathogen and the appearance of the first symptoms) is 6 to 50 hours. Direct detection of the pathogen (Norwalk-like virus) is reportable under the Infection Protection Act. Reporting requirement only for direct detection from stool. Rotavirus (RV gastroenteritis, RVGE) is the most common agent of diarrheal illness in infants and young children and the third most common agent of diarrhea in adults. In adults, infection often occurs during travel or through infection in infected children. Peak incidence is during the winter months (seasonal peak usually in March). Transmission occurs by smear or droplet infection, but also through contaminated water and food. The incubation period is about one to three days. The highest incidence (frequency of new cases) is in infants and one-year-old children; boys are more often affected than girls. Direct or indirect detection of rotavirus is reportable under the Infection Protection Act if the evidence indicates acute infection. Other viruses that can cause enteritis are adenoviruses or enteroviruses. Notice. Approximately 70% of all acute gastroenteritis in children is caused by viruses (noroviruses, rotaviruses, and adenoviruses).
Other forms of enteritis
Caused by allergens
Patients with food allergy may also develop enteritis. This is then called enteritis allergica. It is an inflammation of the whole intestine with mucosal swelling and tissue eosinophilia – presence of so-called eosinophilic granulocytes in the tissue.
Caused by toxins (poisons)
Due to some heavy metals – e.g., mercury or lead – or toxin-producing bacteria such as staphylococci or Bacillus cereus, nausea, sudden vomiting, cramping pain, and diarrhea may occur within a few hours.
Radiogenic (radiation-related)
The sensitive enterocytes (intestinal cells) can be damaged by radiatio (radiation therapy) and radiation enteritis may develop as a result.Note on bacterial pathogens in children:
- Bacterial pathogens (Campylobacter jejuni, Yersinia, Salmonella, Shigessen, pathogenic E. coli or Clostridium difficile) can be detected in the stool in about 20% of children.
- Caution. In about 5% of cases, parasites (cryptosporidia, Entamoeba histolytica, lamblia and others) are the cause of infectious intestinal disease.
Etiology (causes)
Behavioral causes
- Diet
- Consumption of raw foods – e.g., raw dairy products, eggs, meat, fish (salmonella) or spoiled foods, e.g., potato salad left too long in a warm environment
- Very cold food
- In case of food allergy – consumption of allergy-triggering foods such as milk, egg, chocolate, yeast, nuts, cheese, fish, fruits, vegetables.
- Micronutrient deficiency (vital substances) – see prevention with micronutrients.
- Consumption of stimulants
- Alcohol (woman: > 40 g/day; man: > 60 g/day).
- Nonbreastfeeding infants: This increases the relative risk for the occurrence, prevalence (disease incidence) and mortality (death rate) of acute infectious gastroenteritis.
Disease-related causes
- Immunodeficiency
- Reduced general condition – e.g. underweight.
Medication
- Antibiotics – inadequate and untargeted antibiotic treatment can lead to a shift in the intestinal flora and subsequently to enteritis (inflammation of the intestine)
- Proton pump inhibitors (PPIs; acid blockers) – is associated with an increased number of acute gastroenteritis during the winter months: adjusted relative risk (ARR) of acute gastroenteritis was 1.81, which was significant with a 95% confidence interval of 1.72 to 1.90; there was one additional gastroenteritis per 153 PPI users (“number needed to harm”).
X-rays – irradiation for tumor disease.
- Radiation enteritis
