EHEC infections are caused by certain Escherichia coli bacteria, which have the basic property of producing certain toxins. In Germany, the most common serovar is E. coli O157:H7. EHEC infections occur worldwide. The registered frequency in Germany is currently still very dependent on the use of laboratory diagnostic facilities.

Where does EHEC occur?

Ruminants, especially cattle, sheep and goats, but also wild ruminants (especially deer and roe deer) are considered the main reservoir for EHEC.

How does the infection occur?

Transmission is fecal -oral, by contact or smear infection. The incubation period (time from ingestion of the pathogen to illness) is usually one to three days, but it can last up to 8 days.

How long does the contagiousness last?

The infectiousness exists as long as EHEC bacteria are detected in the stool. As a rule, bacterial excretion lasts 5-10 (sometimes up to 20) days, but can also last over a month (especially in children).

What are the clinical symptoms?

About one-third of manifest disease appears as mild diarrhea. The disease usually begins with watery diarrhea that becomes increasingly watery and bloody as the disease progresses and may resemble dysentery. Accompanying symptoms are nausea, vomiting and increasing abdominal pain (pain in the abdomen), rarely fever. In 10-20% of patients, hemorrhagic colitis develops as a severe form with abdominal pain, bloody stools, and often with fever. Experience has shown that infants, small children, the elderly and immunocompromised persons are more likely to contract the disease severely. The following complications are feared: -hemolytic uremic syndrome (HUS) with hemolytic anemia, renal failure up to anuria and thrombotic microangiopathy, and -thrombotic thrombocytopenic purpura (TTP) with thrombocytopenia, skin hemorrhages, hemolytic anemia and neurological changes. These severe complications occur in approximately 5-10% of EHEC infections, regardless of the severity of the previous course of EHEC infection. The symptomatology depends on the site of primary damage from the toxins. The lethality (mortality) in HUS and TTP is high, especially in children. Acute renal failure with dialysis is often seen, and more rarely irreversible renal function loss with chronic dialysis.

What measures can protect preventively?

Important are:

• Strict adherence to hygiene regulations in the extraction, processing, storage, transport and sale of food. (e.g., meat, meats, cold cuts, milk and milk products, delicatessen salads) as well as washing hands thoroughly at all times.

For children and other infected persons, § 34 para. 1 of the Infection Protection Act (IfSG) comes into force. Re-admission is possible after clinical recovery and the presence of three consecutive negative stool results at intervals of one to two days. A written certificate is required. According to § 34 para. 2 IfSG, excretors of EHEC are generally not allowed to visit community facilities until 3 consecutive negative stool samples are available (one to two days apart). Exceptions are possible with the approval of the Office for Health and Consumer Protection and in compliance with the protective measures ordered against the excretor and the community facility. According to § 42 para. 1 IfSG, there is a ban on the activity or occupation of persons involved in the manufacture, treatment or marketing of foodstuffs until 3 negative stool results have been presented. The ban on activities is imposed by the Office for Health and Consumer Protection. Exclusion of contact persons is not necessary as long as no enteritic (diarrhea) symptoms occur and compliance with the required hygiene measures is ensured. However, 3 stool samples per contact person should be examined in the environmental examinations (§ 34 para. 3 IfSG).