By following this link you'll go directly to the site map at the end of each page
   Person in charge: Stefano Morabito
You're in:
Focus on



A ProMED-mail post <> ProMED-mail is a program of the International Society for Infectious Diseases <>

Date: Sat 7 Sep 2019
Source: Food Safety News [edited] <>

Norwegian authorities are investigating an outbreak of _E. coli_ where 4 people have developed hemolytic uremic syndrome.

The Norwegian Institute of Public Health (Folkehelseinstituttet) has identified the same type of enterohemorrhagic _E. coli_ (EHEC) in 3 people since August 2019, and investigations are ongoing for 2 other cases. The outbreak is caused by Shiga toxin-producing _E. coli_ O?: H2 (stx2a, eae, ehxA) infection as no O-group has been identified.

The EHEC pathotype is defined by the presence of the genes encoding Shiga toxin (Stx) type 1, type 2, or both. Stx2a is associated with causing severe disease. The _E. coli_ attachment and effacing (eae) gene produces the virulence factor intimin. When present with stx2a, there is a strong association with the risk of HUS. The enterohaemolysin gene (ehxA) is another virulence factor. EHEC can also be called Shiga toxin-producing _E. coli_ (STEC) or Verocytotoxin-producing _E. coli_ (VTEC).

An outbreak investigation has been started with the relevant municipal agencies, the Veterinary Institute, and Norwegian Food Safety Authority (Mattilsynet) as the source is unknown.

Patients live in Hordaland, Aust-Agder, Trondelag, and Hedmark. One child and 4 adults over 70 years of age are sick. Four people have developed hemolytic uremic syndrome (HUS), a type of kidney failure associated with _E. coli_ infection. Bacteria with similar DNA profiles have been detected in 3 patients, while analysis for the other 2 cases is ongoing. Similar DNA profiles indicate that people have a common source of infection. Interviews have been conducted to identify whether the patients have a common source of infection. Audits of places such as catering establishments have been done in an attempt to reveal a possible source of infection.

The DNA profile of the bacteria in the outbreak has not been seen in Norway before. The Norwegian Institute of Public Health has contacted international partners to see whether other countries have been affected.

In 2018, 494 EHEC infections were reported to the Norwegian Institute of Public Health, but only 8 developed the serious complication of HUS.

Symptoms of _E. coli_ infection include abdominal cramps and diarrhea that can become bloody. Fever and vomiting may also occur. The incubation period can range from 3-8 days, and most patients recover within 10 days.

_E. coli_ is transmitted to humans primarily through consumption of contaminated food, such as raw or undercooked ground meat, raw milk, and raw vegetables and sprouts.

Communicated by: ProMED-mail <>

[ProMED would appreciate more information regarding this strain and outbreak.

It is likely that the somatic (O antigen) may be a rare one and that appropriate antisera were not readily available, as all Enterobacteriaceae should have an O antigen.

EHEC strain serotype O80:H2 have been described in Soysal N, Mariani-Kurkdjian P, Smail Y, et al. Enterohemorrhagic _Escherichia coli_ hybrid pathotype O80:H2 as a new therapeutic challenge. Emerg Infect Dis 2016; 9: 1604-12, which brought forth more information regarding this unusually invasive hybrid EHEC, which contains a rare variant of the intimin gene and genetic determinants related to a plasmid, found mostly in avian pathogenic _E. coli_ and _E. coli_ that causes human neonatal meningitis, which is associated with extraintestinal virulence. This group, led by Stephane Bonacorsi, originally reported this atypical organism in an adult associated with HUS with a relapse associated with bacteremia (Mariani-Kurkdjian P, Lemaire C, Bidet P, et al. Haemolytic-uraemic syndrome with bacteraemia caused by a new hybrid _Escherichia coli_ pathotype. New Microbes New Infect 2014; 2(4): 127-131).

The 2016 study reported that 96 percent of the cases were associated with HUS, but the authors do point out that the surveillance system for EHEC is voluntary in France, and PCR assays for Shiga toxin in stool are only done in cases involving diarrhea with HUS suspicion, so the denominator of total O80:H2 cases is not known. Likewise, whether this organism is zoonotic is also not clear, and the areas in France with this strain are not where most cases of _E. coli_ O157 are reported.

Regarding the use of antimicrobials, the issue is relevant in these cases since some of them are associated with bacteremia which requires antimicrobial therapy. Azithromycin and ceftriaxone were not associated with increasing Shiga toxin production whereas ciprofloxacin was, in this study. In the large _E. coli_ O104:H4 outbreak in northern Germany, therapy was also used, especially in those cases where the colon was perforated. In those reports, the carbapenem antimicrobials also did not increase toxin production. Whether these effects are strain specific is not clear at this time so should not necessarily be generalized to all EHEC. Of note, the _E. coli_ O104:H4 strain was a genetic hybrid between EHEC and enteroaggregative _E. coli_ and was not thought to be a zoonosis.

Extraintestinal invasive strains of EHEC will indeed introduce another layer of concern about these infections. - Mod.LL

HealthMap/ProMED map available at: Norway: <>]

[See Also:
E coli EHEC - Denmark: hemolytic uremic syndrome, fatal
E. coli EHEC - Iceland (03): O26, ice cream susp
E. coli EHEC - Iceland (02)
E. coli EHEC - Iceland:
E. coli EHEC - France: O26, unpasteurized cheese

E. coli EHEC - France (03): O26, unpasteurized cheese, more cases
E. coli EHEC - Europe: O80:H2, hybrid invasive pathogen, antimicrobial resistance
E. coli EHEC - Sweden: RFI
E. coli EHEC - Norway: O157, RFI
E. coli EHEC - Ireland (02): increased numbers
E. coli EHEC - France (02): O26, unpasteurized cheese, more cases
E. coli EHEC - Ireland: (Ulster) childcare center
E. coli EHEC - France: O26, unpasteurized cheese, alert, recall
E. coli EHEC - Canada: cheese, 2013, 60 day rule
E. coli EHEC - Denmark: O26
E. coli EHEC - UK (02): (England) O157, raw pet food, fatal, 2017
E. coli EHEC - UK: (England) fatal
E. coli EHEC - Ireland (03): (GY) daycare]

Published 04-10-2017 in Focus on , last update 11-09-2019


Legal information

© - Istituto Superiore di Sanità Viale Regina Elena 299 - 00161 - Roma (I)
Partita I.V.A. 03657731000 - C.F. 80211730587 - Legal information

ISS Home

Informiamo i visitatori, in virtù della individuazione delle modalità semplificate per l'informativa e l'acquisizione del consenso per l'uso dei cookie - 8 maggio 2014 (Pubblicato sulla Gazzetta Ufficiale n. 126 del 3 giugno 2014), che questo sito utilizza direttamente solo cookie tecnici.[Ho letto]