What is Salmonella Carrau?

What is Salmonella carrau, which was implicated in the recent recall of pre-cut fruits from Caito Foods? And what is the deal with Salmonella carrau and melons?

Does this Serotype Just Like Melons?

Salmonella carrau is a relatively rare serotype. It was first isolated in 1936 from the glands of pigs. A bit later, it was isolated for the first time from human subjects: two strains were taken from babies with diarrhea, and two more from adults stricken with stomach problems. Another strain was taken from a group of flies, and another was isolated from a blood culture taken from a sick man.

Those first six isolates, including those from the pigs, the flies, the babies, and the first two adults, were initially found in Uruguay. The seventh isolate — that taken from the blood culture — originated in Mexico.

Not Just Melons

Carrau has occasionally shown up in domestic pets. A survey of the diarrhea of dogs and cats for salmonella between the years of 2012 and 2014 found carrau isolates. Sixty out of some 2,442 dogs tested positive for salmonella; of the isolates taken from those sixty dogs, there were 27 different serovars of the bacteria. One of those 27 serovars was Salmonella Carrau — initially misidentified by the genetic testing before being correctly pegged on re-examination.

Oddly enough, salmonella carrau has shown up in reptiles as well. A 2007 letter to the Brazilian Journal of Veterinary Pathology described carrau showing up in South American river turtles. It’s also been found in tegu lizards.

The occasional presence of carrau in dogs, cats, turtles, and lizards which are occasionally kept as pets is significant. We don’t frequently eat those animals, but we do keep them as pets. Reptiles and mammals both can have salmonella in their systems without demonstrating any symptoms.

That poses a risk to pet owners and others who interact with the animals. Even if the animal doesn’t appear sick, they can still shed the salmonella, often through their feces. A human being who takes it upon themselves to clean up the leavings of those animals can then contract the salmonella therein. That is, in short, why it’s relevant that these animals sometimes have shown with carrau, and why it’s a big deal when raw pet food is recalled over fears of potential contamination: pathogens that pets pick up from their food can easily be passed on to their owners.

Still Rare Though

Despite the occasional presence of carrau in animals, however, it’s still a relatively rare form of salmonella in the United States. Between 1997 and 2007, salmonella carrau was isolated from sick individuals some 77 times. That makes it significantly more obscure than the handful of salmonella serotypes that are most often responsible for foodborne illness in the United States, but still more common than the majority of the two and half thousand plus types of salmonella that have so far been described.

Curiously, those 77 isolates seem to indicate a bump in the prevalence of carrau. Between 1968 and 2008, only 235 human isolates had been recorded in the United States. That changed in 2009, when the Wisconsin Department of Public Health registered a cluster of foodborne illnesses caused by salmonella carrau. Subsequent investigation showed that the outbreak wasn’t limited to Wisconsin; fifty two different people in 18 states had been affected. Eighty four percent of the subjects were women. Four ended up in the hospital, and one victim was so sick that they tragically lost their life.

Public health investigators were then faced with the task of trying to figure out how those people had ended up ill. They pulled together a control group for comparison and began to interview both the control and those affected by the outbreak to find out what they had eaten before the onset of the illness.

The distinguishing factor, curiously enough, ended up being fruit salad. Most of the people who had gotten sick reported eating fruit salad before the onset of their illness; on the other hand, most of those in the control group reported that they hadn’t eaten fruit salad. That meant that the fruit salad was likely the source of the outbreak.

Although investigators weren’t able to identify a particular brand of fruit salad or business responsible for the outbreak, they were able to come up with a more specific factor linking the cases together: melons. All the fruit salads had melon in them.

That’s weird because this most recent outbreak of salmonella carrau also involves melons. Caito Foods, whose pre-cut fruits were also the source of an outbreak this time last year, have recalled a whole ream of different melon products over fears of contamination with salmonella carrau.

Is it significant that the only two major outbreaks of salmonella carrau described in the United States have been traced back to melons? It’s hard to say. If there’s a paper out there that describes a particular affinity that salmonella carrau has for melons, this writer has not heard of it. It could well be a coincidence that both outbreaks described have been caused by the same fruit.

Could the Rind Be It?

One potential explanation could be that melons are fruits with rinds. People often erroneously think that they don’t have to wash fruits protected by rinds – that the rind will have kept out bacteria which might otherwise contaminate the fruit. They then cut through the rind with a clean knife, thinking that all is well.

It’s not. If you don’t wash the rind before cutting, it doesn’t matter if the knife is clean: foodborne pathogens can be transferred by the act of cutting itself from the outside to the inside of the fruit. That’s one potential explanation for why salmonella carrau keeps showing up on melons: because people aren’t washing their melons first. Stay vigilant, and wash your melons! And let us know if you know more about the relationship between melons and this rare-ish type of salmonella.

The Lange Law Firm

Our mission is to help families who have been harmed by contaminated food or water.  When corporations cause Salmonella food poisoning outbreaks or Legionnaires’ disease outbreaks, we use the law to hold them accountable.  The Lange Law Firm, PLLC is the only law firm in the nation solely focused on representing families in food poisoning lawsuits and Legionnaires disease lawsuits.

If you were infected with Salmonella after eating fresh cut melon or melon mixes and are interested in making a legal claim for compensation, we have a Salmonella lawyer ready to help you.  Call us for a free no obligation legal consultation at (833) 330-3663 or send us an e-mail here.

By: Sean McNulty, Contributing Writer (Non-Lawyer)