# 5572
Roughly 48 hours ago German-doctor – a moderator on FluTrackers – posted one of the earliest media reports on an apparent outbreak of Enterohemorrhagic Escherichia coli (EHEC) in Germany resulting in at least 3 deaths, 400 illnesses, and 80 cases of HUS (Hemolytic Uremic Syndrome) over the past couple of weeks.
HUS is a rare but serious complication that can occur when an infection – usually E. coli O157:H7, but sometimes shigella and salmonella – produce toxins that can destroy red blood cells and cause kidney damage.
These toxins are usually referred to as verotoxins (or sometimes shiga-like toxins), and so the strains of E. Coli that can produce them are sometimes classified as VTEC (Verotoxin-Producing E. coli).
Not everyone who consumes verotoxin producing strains of E. coli will develop symptoms, however, and fewer still will go on to experience HUS.
Over the past two days a number of additional reports have appeared, including two releases from ProMed Mail (here and here), a blog on Nature News, several posts by Crof (see here, here, and here) and the following brief video report from Euronews.
While food borne illnesses due to E. coli contamination are hardly rare, the cases reported in Germany over the past several weeks don’t fit the usual profile.
- First, Germany normally sees 80 or so cases a month, and the number of cases thus far in May are running more than 5 times that rate.
- Second, EHEC is mostly seen in young children, who are particularly susceptible to the toxins produced by the E. coli bacteria. In this outbreak, most of the burden has been on young, adult women.
- And third, by far the most commonly reported strain of EHEC is called 0157:H7, but early testing indicates that the causative agent is a non-O157 form of E. coli (reportedly similar o E. coli O104)
We’ve also seen reports suggesting that this strain of E. coli may be unusually resistant to antibiotics. More involved genetic testing is underway in order to better identify and understand the pathogen.
Obviously the sudden appearance of an unusual serotype of Escherichia coli that has sickened hundreds of (mostly) young women in a developed nation like Germany has generated a good deal of concern.
The source of the bacteria remains unknown – although fresh uncooked vegetables are suspected. The CDC lists the following as common sources of E. Coli infection:
Major source is ground beef; other sources include consumption of unpasteurized milk and juice, sprouts, lettuce, and salami, and contact with cattle. Waterborne transmission occurs through swimming in contaminated lakes, pools, or drinking inadequately chlorinated water. Organism is easily transmitted from person to person and has been difficult to control in child day-care centers.
Americans with long memories may recall that E. Coli food poisoning leapt into the national consciousness nearly 20 years ago after an outbreak of serotype O157:H7 in the Western United States.
The CDC’s MMWR in 1993 carried this synopsis:
From November 15, 1992, through February 28, 1993, more than 500 laboratory-confirmed infections with E. coli O157:H7 and four associated deaths occurred in four states -- Washington, Idaho, California, and Nevada. This report summarizes the findings from an ongoing investigation (1) that identified a multistate outbreak resulting from consumption of hamburgers from one restaurant chain.
Remarkably, E. Coli O157:H7 wasn’t recognized as a pathogen until 1982, when the CDC detected it in the stool samples from four patients in two states.
Three of four patients had an unusual bloody diarrheal illness, while the fourth (a spouse of one of the other patients) developed non-bloody diarrhea.
But it wasn’t until the infamous 1993 Jack-in-the-Box hamburger outbreak ten years later that this pathogen gained notoriety as a serious health threat.
The following comes from the CDC’s MMWR Epidemiology of Escherichia coli O157:H7 Outbreaks, United States, 1982–2002.
In 1994, E. coli O157 became a nationally notifiable infection, and by 2000, reporting was mandatory in 48 states.
An estimated 73,480 illnesses due to E. coli O157 infection occur each year in the United States, leading to an estimated 2,168 hospitalizations and 61 deaths annually (5), and it is an important cause of acute renal failure in children (6,7).
There are more than 200 strains of E. coli, of which only a handful cause illness in humans. Most E. coli are actually beneficial bacteria, and are part of the normal flora of the gut.
But among the virulent types, increased toxin generation and growing antibiotic resistance are serious concerns.
Maryn McKenna – our favorite `scary disease girl’ – has written at length on the dangers of antibiotic overuse on the farm, and only a couple of months ago wrote about the creation of antibiotic resistant E. coli on the farm.
Drug-Resistant Bacteria: To Humans From Farms via Food
This is a timely blog, considering the news out of Germany, and well worth reviewing.
Meanwhile, the next few days should give us a much better idea about the extent of the outbreak in Germany, the mode of transmission, and the genetic makeup and traits of the pathogen.
Stay tuned.
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