OVERVIEW

What is German Enterohemorrhagic Escherichia coli O104 Infection?

German Enterohemorrhagic Escherichia coli O104 infection is an acute infectious disease.

From May to July 2011, an outbreak of an acute infectious disease characterized by "bloody diarrhea" and "hemolytic uremic syndrome (HUS)" occurred among residents in Germany and some other countries, as well as travelers who had visited Germany. The pathogen responsible for this outbreak was Enterohemorrhagic Escherichia coli O104.

Nearly half of the patients required hospitalization for supportive treatment, such as fluid replacement and dialysis. Antibiotics showed no significant effect on this disease.

Patients without complications usually recovered within about one week. The mortality rate was approximately 1%–2%; 39% of patients experienced kidney-related complications, such as hypertension, proteinuria, or abnormal kidney function; 4% developed neurological sequelae, such as epilepsy, coma, or motor function impairment.

Is German Enterohemorrhagic Escherichia coli O104 Infection Common? Where is It Commonly Found (Epidemic Areas)?

German Enterohemorrhagic Escherichia coli O104 infection primarily occurred during an outbreak from May to July 2011 in Germany and among travelers who had visited Germany. It also affected some European countries, as well as the United States and Canada.

Have There Been Any Cases of German Enterohemorrhagic Escherichia coli O104 Infection in China?

None so far.

SYMPTOMS

How long is the incubation period for German enterohemorrhagic E. coli O104 infection?

2 to 10 days, commonly 3 to 4 days.

What symptoms does German enterohemorrhagic E. coli O104 infection cause?

Symptoms vary in severity among patients.

• Mild cases often present with atypical symptoms, such as abdominal pain, watery stools, low-grade fever, or no fever.
• Severe cases manifest as hemorrhagic colitis, with rapid onset of intermittent pain in the lower right abdomen, initially watery diarrhea followed by bloody diarrhea, possibly accompanied by nausea and vomiting. Some patients develop neurological symptoms, such as restlessness, speech impairment, or seizures. A subset of patients may develop hemolytic uremic syndrome (HUS) 5–7 days after infection, characterized by sudden onset, rapid progression, and critical condition, including oliguria or anuria, hematuria, hemoglobinuria, and, in rare cases, death.

What serious complications can German enterohemorrhagic E. coli O104 infection lead to?

If complicated by hemolytic uremic syndrome (HUS), the infection becomes severe, potentially causing oliguria or anuria, hematuria, hemoglobinuria, and, in rare cases, death.

How high is the mortality risk from German enterohemorrhagic E. coli O104 infection?

The mortality rate is typically 1%–2%, but higher among elderly patients and those who develop hemolytic uremic syndrome (HUS).

CAUSES

What are the characteristics of German enterohemorrhagic Escherichia coli O104?

Escherichia coli (also known as E. coli) is normally present in the human gastrointestinal tract, but if the genes of E. coli mutate for some reason, it can cause disease.

E. coli can be classified based on differences in the lipopolysaccharide (O antigen) on the bacterial outer membrane and the bacterial flagella (H antigen). The O antigen of the E. coli strain responsible for the outbreak in Germany is coded as 104, hence it is called enterohemorrhagic E. coli O104.

Enterohemorrhagic E. coli O104 can produce Shiga toxin, causing bloody diarrhea, hemolytic uremic syndrome, worsening the condition, and even leading to death. It can also produce extended-spectrum β-lactamase, rendering antibiotics ineffective.

Is German enterohemorrhagic Escherichia coli O104 contagious?

German enterohemorrhagic E. coli O104 is primarily transmitted through food, usually due to consuming raw vegetables contaminated with the bacteria.

Person-to-person transmission is relatively rare. Some patients infected with German enterohemorrhagic E. coli O104 may shed the bacteria for an extended period, with an average shedding duration of 17–18 days, and in some cases, up to 157 days or longer. However, person-to-person transmission of enterohemorrhagic E. coli O104 is uncommon.

Who is susceptible to German enterohemorrhagic Escherichia coli O104 infection?

The general population is susceptible. Based on reported cases, 88% of patients were aged 17 or older, and over 60% were female.

DIAGNOSIS

What are the suspected cases of German enterohemorrhagic Escherichia coli O104 infection?

Enterohemorrhagic Escherichia coli O104 infection should be suspected in patients with acute bloody diarrhea or hemolytic uremic syndrome, especially when accompanied by abdominal tenderness and absence of fever.

This disease should also be suspected in individuals who have traveled to Germany during an outbreak of Escherichia coli O104 infection.

What tests are needed for German enterohemorrhagic Escherichia coli O104 infection?

First, the doctor will perform a physical examination, primarily checking for signs of anemia, pallor in the conjunctiva and lips, increased heart rate, as well as palpating the abdomen to assess hardness and tenderness.

The key is to conduct laboratory tests to confirm Escherichia coli O104 infection, including stool tests and blood tests.

How is German enterohemorrhagic Escherichia coli O104 infection diagnosed?

For patients suspected of having German enterohemorrhagic Escherichia coli O104 infection, the diagnosis can be confirmed if at least one of the following four test results is positive:

• Isolation of Escherichia coli from stool with detection of Shiga toxin;
• Stool culture yielding Escherichia coli along with other pathogens, and nucleic acid testing detecting Shiga toxin genes;
• Detection of anti-Escherichia coli O104 IgM antibodies in blood, or a fourfold or higher increase in IgG antibody levels during the convalescent phase compared to the acute phase.

Which diseases have similar manifestations to German enterohemorrhagic Escherichia coli O104 infection? How are they distinguished?

German enterohemorrhagic Escherichia coli O104 infection may resemble symptoms of other Escherichia coli infections, such as Escherichia coli O157 infection.

The distinction is primarily made through stool examination, bacterial isolation and culture, as well as blood tests for serum antibodies.

TREATMENT

Which department should I visit for German enterohemorrhagic E. coli O104 infection?

Infectious diseases department, gastroenterology department, or general internal medicine. Severe cases may be treated directly in the emergency department.

Do patients with German enterohemorrhagic E. coli O104 infection need isolation?

Enteric isolation is required.

• Place the patient in a single room, separate from other patients;
• Strictly disinfect hands after each contact with the patient, using Lysol solution to soak and sanitize hands and any utensils touched;
• The patient's tableware and toilet must be dedicated, and vomit or excrement should be disinfected with bleaching powder before disposal.

How is German enterohemorrhagic E. coli O104 infection treated?

Current evidence suggests that antibiotics may promote the release of Shiga-like toxins, increasing the risk of hemolytic uremic syndrome (HUS). Therefore, antibiotic treatment is not recommended for confirmed cases.

Symptomatic and supportive care is the main approach, including:

• Bed rest;
• A liquid, easily digestible, low-residue diet;
• Rehydration—oral for mild cases, intravenous for severe cases, adjusted based on dehydration level to prevent electrolyte imbalance, with urine alkalization if needed;
• Avoiding antidiarrheals or motility inhibitors, as they may prolong intestinal retention of Shiga-like toxins;
• Monitoring serum creatinine, urea nitrogen, platelets, and urinalysis in severe cases to detect complications early;
• For HUS, fresh plasma transfusion or plasmapheresis may be considered, with prompt dialysis if kidney dysfunction occurs.

Can German enterohemorrhagic E. coli O104 infection be completely cured?

Yes.

Uncomplicated cases typically resolve within about a week, but not all patients fully recover.

• The mortality rate is usually 1%–2%, higher in elderly patients or those with HUS;
• 39% of patients may experience kidney-related sequelae (e.g., hypertension, proteinuria, renal dysfunction);
• 4% may develop neurological complications (e.g., seizures, coma, motor impairments).

DIET & LIFESTYLE

What dietary precautions should patients with German enterohemorrhagic E. coli O104 infection take?

Due to significant fluid loss from diarrhea, patients should replenish adequate daily fluids, so they are encouraged to drink plenty of water.

They should consume a high-calorie, high-nutrition, easily digestible, low-residue, and low-fiber liquid or semi-liquid diet. After appetite recovers, food intake should gradually increase. Avoid uncontrolled eating and hard foods to prevent intestinal dysfunction and intestinal bleeding.

What lifestyle precautions should patients with German enterohemorrhagic E. coli O104 infection take?

• Bed rest is recommended during illness, with gradual increase in activity after recovery.
• If fever occurs, avoid excessive use of antipyretics to prevent dehydration from profuse sweating.
• Pay attention to skin care during bed rest, keeping the skin clean and dry.
• Maintain oral hygiene by cleaning the mouth regularly to prevent oral infections.

PREVENTION

How to Prevent Infection with Enterohemorrhagic Escherichia coli O104 in Germany?

If you are in an area where enterohemorrhagic Escherichia coli O104 is prevalent, the following measures can help prevent infection:

• Practice hand hygiene—wash hands thoroughly before cooking, eating, after using the toilet, handling garbage, or touching animals;
• Stay home if experiencing diarrhea until symptoms improve, and handle waste properly;
• Ensure food safety—avoid unpasteurized milk and foods made with it, wash fruits and vegetables thoroughly, cook meat and seafood thoroughly, ensure eggs are cooked until the yolk is firm, and wash hands, knives, and cutting boards after handling raw food.