[Clinical symptoms, treatment and outcome of EHEC and EHEC-HUS patients treated as in-patients]

Public Health Research Resulting from One of the World's Largest Outbreaks Caused by Entero-Hemorrhagic Escherichia coli in Germany 2011: A Review

In 2011, Germany experienced one of the largest outbreaks of entero-hemorrhagic Escherichia coli (EHEC) ever reported. Four years thereafter, we systematically searched for scientific publications in PubMed and MEDPILOT relating to this outbreak in order to assess the pattern of respective research activities and to assess the main findings and recommendations in the field of public health. Following PRISMA guidelines, we selected 133 publications, half of which were published within 17 months after outbreak onset. Clinical medicine was covered by 71, microbiology by 60, epidemiology by 46, outbreak reporting by 11, and food safety by 9 papers. Those on the last three topics drew conclusions on methods in surveillance, diagnosis, and outbreak investigation, on resources in public health, as well as on inter-agency collaboration, and public communication. Although the outbreak primarily affected Germany, most publications were conducted by multinational cooperations. Our findings document how soon and in which fields research was conducted with respect to this outbreak.

Diffusion-weighted imaging of the kidneys in haemolytic uraemic syndrome

OBJECTIVES

To evaluate the kidneys of patients with haemolytic uraemic syndrome (HUS) using diffusion-weighted imaging (DWI) and Doppler ultrasound (US) compared with healthy controls.

MATERIALS AND METHODS

Fifteen patients (mean age 33.3 years; three male; 12 female) with diarrhoea-positive HUS and 15 healthy volunteers were prospectively evaluated with DWI and Doppler US. A total apparent diffusion coefficient (ADC_TOT), and ADCs predominantly reflecting microperfusion (ADC_LOW) and diffusion (ADC_HIGH) were calculated. Doppler US evaluated renal vascularity and flow.

RESULTS

When compared with controls, kidneys affected by HUS showed reduced cortical ADC values (ADC_TOT 1.79±0.22 vs. 2.04±0.1x10^-3 mm²/s, P 0.001), resulting in either low corticomedullary differences (11/15 patients) or an inverted corticomedullary pattern (4/15 patients). Reduction of cortical ADC values was associated with a decrease of cortical vascularity on Doppler US (ADC_TOT, P<0.001; ADC_LOW, P 0.047). Kidneys with complete absence of the cortical vasculature on Doppler US (four patients) also demonstrated limited diffusion (ADC_HIGH, P 0.002). Low glomerular filtration rate, requirement for haemodialysis during hospitalization, and longer duration of haemodialysis were associated with decreased cortical diffusivity (ADC_TOT: P 0.04, 0.007, and <0.001, respectively).

CONCLUSION

DWI shows qualitative and quantitative abnormalities in kidneys affected by HUS, thereby extending the non-invasive assessment of renal parenchymal damage.

KEY POINTS

• In HUS, DWI is feasible for functional characterization of kidney involvement. • Kidneys affected by HUS showed reduced cortical diffusivity. • Decreased cortical diffusivity was associated with lower kidney function. • Requirement and duration of haemodialysis was linked to degree of cortical alterations.

Symptoms and clinical course of EHEC O104 infection in hospitalized patients: a prospective single center study

OBJECTIVES

Shiga-toxin producing O157:H7 Entero Haemorrhagic E. coli (STEC/EHEC) is one of the most common causes of Haemolytic Uraemic Syndrome (HUS) related to infectious haemorrhagic colitis. Nearly all recommendations on clinical management of EHEC infections refer to this strain. The 2011 outbreak in Northern Europe was the first to be caused by the serotype O104:H4. This EHEC strain was found to carry genetic features of Entero Aggregative E. coli (EAEC) and extended spectrum β lactamase (ESBL). We report symptoms and complications in patients at one of the most affected centres of the 2011 EHEC O104 outbreak in Northern Germany.

METHODS

The courses of patients admitted to our hospital due to bloody diarrhoea with suspected EHEC O104 infection were recorded prospectively. These data include the patients' histories, clinical findings, and complications.

RESULTS

EHEC O104 infection was confirmed in 61 patients (female = 37; mean age: 44±2 years). The frequency of HUS was 59% (36/61) in our cohort. An enteric colonisation with co-pathogens was found in 57%. Thirty-one (51%) patients were treated with plasma-separation/plasmapheresis, 16 (26%) with haemodialysis, and 7 (11%) with Eculizumab. Patients receiving antibiotic treatment (n = 37; 61%) experienced no apparent change in their clinical course. Twenty-six (43%) patients suffered from neurological symptoms. One 83-year-old patient died due to comorbidities after HUS was successfully treated.

CONCLUSIONS

EHEC O104:H4 infections differ markedly from earlier reports on O157:H7 induced enterocolitis in regard to epidemiology, symptomatology, and frequency of complications. We recommend a standard of practice for clinical monitoring and support the renaming of EHEC O104:H4 syndrome as "EAHEC disease".

Central nervous system involvement in adults with epidemic hemolytic uremic syndrome

Hemolytic uremic syndrome is a multisystem disorder that is caused by infection with Shiga-toxin-producing Escherichia coli. HUS affects mainly children and is rare among adults. This retrospective case series analyzes clinical signs and MR imaging findings of 11 adult patients with HUS associated nervous system involvement during the epidemic EHEC outbreak in northern Europe with its epicenter in Hamburg in May 2011. The most prevalent imaging finding was symmetric pointy vasogenic edema of the brain stem in the acute and subacute phases of the disease (n = 5). One patient exhibited additional symmetric mesiotemporal signal changes mimicking limbic encephalitis. Two patients developed subcortical patchy lesions, and 4 subjects did not present with any signal changes. Remarkably, territorial ischemia, signs of hemorrhage, or blood-brain barrier disruption have not been detected. While brain stem lesions were transient and normalized with clinical recovery, supratentorial lesions did not resolve completely at 2-month follow-up examination.

Validation of treatment strategies for enterohaemorrhagic Escherichia coli O104:H4 induced haemolytic uraemic syndrome: case-control study

OBJECTIVE

To evaluate the effect of different treatment strategies on enterohaemorrhagic Escherichia coli O104:H4 induced haemolytic uraemic syndrome.

DESIGN

Multicentre retrospective case-control study.

SETTING

23 hospitals in northern Germany.

PARTICIPANTS

298 adults with enterohaemorrhagic E coli induced haemolytic uraemic syndrome.

MAIN OUTCOME MEASURES

Dialysis, seizures, mechanical ventilation, abdominal surgery owing to perforation of the bowel or bowel necrosis, and death.

RESULTS

160 of the 298 patients (54%) temporarily required dialysis, with only three needing treatment long term. 37 patients (12%) had seizures, 54 (18%) required mechanical ventilation, and 12 (4%) died. No clear benefit was found from use of plasmapheresis or plasmapheresis with glucocorticoids. 67 of the patients were treated with eculizumab, a monoclonal antibody directed against the complement cascade. No short term benefit was detected that could be attributed to this treatment. 52 patients in one centre that used a strategy of aggressive treatment with combined antibiotics had fewer seizures (2% v 15%, P = 0.03), fewer deaths (0% v 5%, p = 0.029), required no abdominal surgery, and excreted E coli for a shorter duration.

CONCLUSIONS

Enterohaemorrhagic E coli induced haemolytic uraemic syndrome is a severe self limiting acute condition. Our findings question the benefit of eculizumab and of plasmapheresis with or without glucocorticoids. Patients with established haemolytic uraemic syndrome seemed to benefit from antibiotic treatment and this should be investigated in a controlled trial.