The E. coli O104:H4 Outbreak Gets More Confusing--and Potentially More Disturbing

Consider this a post wherein I engage in some speculation, and hope that I'm very, very wrong. You see, the 'German' E. coli O104:H4 outbreak ('HUSEC041') has taken a confusing turn:

The strain of E. coli blamed for 46 deaths in Germany appears to have resurfaced in France, the French Ministry of Health said.

The new outbreak has sickened eight people, who went to two hospitals in Bordeaux, authorities said.

Officials interviewed seven of them, all of whom reported having attended an open house at a children's recreation center. Six of them reported having eaten sprouts during the visit, "particularly used in decoration of a gazpacho," the health ministry said.

Two of the eight patients have hemolytic uremic syndrome. The strain of E. coli isolated from one of them "has the same characteristics as the strain responsible for a large epidemic" of enterohemorrhagic E. coli in Germany over the past several weeks, which has been blamed on sprouts, the ministry said in a statement.

The seeds for the sprouts consumed at the recreation center were planted and grown in France, officials said.

An investigation found the seeds were supplied by a British company, but no definitive link has been established, an official with France's economy ministry said.

Meanwhile, the UK has issued a warning about eating sprouts, including "alfalfa, mung beans (usually known as beansprouts) and fenugreek." Not sure what fenugreek is, but you shouldn't be eating it (them?).

One of the downsides of this early post about the misidentification of the outbreak strain is that it has made me into something resembling an authoritative source (fools). So I've tried to stay away from any speculation, since speculation has a way of working through the intertoobz and coming out the other end as a definitive statement. But this latest development leads to me speculate. And speculate the Mad Biologist will.

Simply put, I don't think this is a single point source outbreak: a contaminant enters a single processing facility or farm and spreads through the food chain. In fact, I have never thought this is a single point source outbreak.

Before we had news of this latest outbreak, there were reports of finding HUSEC041 in streams outside of Frankfurt, Germany. I find it unlikely that this cames from a sick person, went through the sewage system, and happened to be the E. coli isolated--most E. coli from any sewage system won't be this outbreak strain (otherwise, there would many thousands of people in Frankfurt--Frankfurters?--with bloody diarrhea and hemolytic uremic syndrome). Unlike E. coli O157:H7, which through some evolutionary flukes has a couple of biochemical changes that allow selective isolation (i.e., you have specifically hunt for it), HUSEC041 looks just like 'normal' E. coli*. If you're observing it in a stream sample, that seems too abundant relative to other E. coli to be a sewage contaminant.

What I think is happening is that HUSEC041 has, for whatever reason, skyrocketed in its reservoir (where it lives outside of people). This has led to separate, multiple introductions into the food supply. While enteroaggregative E. coli ('EAEC') like HUSEC041 aren't supposed to live in non-human animals (children and infants are thought to be the reservoir), EAEC isn't supposed to produce Shiga-like toxin either, so there's a first time for everything. (Of course, no one has been screening asymptomatic H. sapiens for HUSEC041).

I really hope I'm wrong, since if I am, that would mean there was a single point of introduction which will ultimately burn itself out. If I'm not, well, then we have a new strain of shigatoxinogenic E. coli (STEC) to worry about....

*Since HUSEC041 is resistant to multiple antibiotics, I suppose one could select antibiotic resistant isolates. I have no idea if the authorities are doing that.