Wednesday, 6 October 2010

C. diff: Blame hospitals? Or food? (or pigs?)

The American writer, Maryn McKenna, once again seems to be seizing the initiative over zoonotic disease and superbugs. Her articles and books always take us ahead of the crowd and with serious science rendered understandable, too.

She asks if food could be a source of the dreaded C.Diff?

Perhaps, we can add something helpful. 

When C.Diff first hit the headlines, there seemed to be a clear geographical coincidence to pig farms – and specifically pig farms that had circovirus outbreaks and consequent antibiotic use. 

Look how long the writer has been writing about it!

The strain was NAP1/027/BI, usually called 027 in England. You can’t always get the strain named in Britain, but the bad ones seem to be 027. 

There have been many human deaths occurring in hospital outbreaks on both sides of the Atlantic - one of the early ones identified as 027 was at Lowestoft in England in March 2007, others in Canadian pig farming areas.

Geographical coincidence can strike like a hammer blow and be a faster way to the source than anything.

But more recent outbreaks in hospitals did not show such a close association with pig farming.

C.Diff probably now comes in all three ways, hospitals, food and pigs. It could have started in pigs fed with antibiotics to deal with circovirus epidemics; and carried on the person via staff and patients into hospitals in pig raising areas.

Anyway, here is the scary disease girl putting science into accessible English. 

You can get the Full Article Here

C. diff: Blame hospitals? Or food?

By Maryn McKennaDescription: Email Author
October 6, 2010  |

People who are interested in infections that are transmitted in hospitals (umm, ghouls like me) have a special sick relish for Clostridium difficile, or in its short form, C. diff. C. diff lives in the intestines, part of a complex population of many bacteria — you did know there are more bacteria in your body than there are cells that belong to you, right? — but it roars out of control if those other bacteria are wiped out by a course of antibiotics, especially clindamycin. Removing the other bacteria clears out space for C. diff to reproduce in much greater numbers; the toxins it produces irritate the lining of the intestine, producing colitis, and triggering fever, cramps and diarrhea, and in the worst cases, sepsis. miscarriage and death.

C. diff colitis is one of the most common and serious hospital-acquired infections because — if you’re reading this over breakfast, you might want to stop eating now — severe diarrhea in a hospital patient who is confined to a bed and using a bedpan tends to get everywhere. Really, everywhere: bed linens and bedrails, floors and walls, stethoscopes, telephones, computer keyboards, and the hands of the healthcare personnel who operate those devices and then touch another patient.

C. diff persists so spectacularly because in the outside air, it forms a hard-shelled spore that protects its genetic material from assault — including from the alcohol in the hand gel that most healthcare workers use to clean their hands in between patients, and from the stomach acid of patients who swallow it. (See, I told you to stop eating.) Because of that, and because it’s such a devastating infection, hospitals toil incredibly hard at sanitizing to get rid of it,

C. diff colitis is a stubborn and ugly infection. ...

..Starting about 10 years ago, C. diff got dramatically more problematic: more virulent, more resistant to treatment, and more commonly occurring in people who would not have been expected to have it — often, healthy young people who had not been in hospitals, who seemed to be developing the illness in the outside world. Two CDC researchers said in 2008:

In the United States, the number of hospital discharges where (C. diff associated diarrhea, CDAD) was listed as any diagnosis doubled between 2000 and 2003... with a disproportionate increase for persons aged > 64 years. By 2003, regional reports of CDAD outbreaks from hospitals throughout the US and in Quebec, Canada emerged, describing severe disease associated with greater numbers of complications, including colectomies, treatment failures, and deaths. In 2004, the attributable mortality rate of nosocomial CDAD in Quebec hospitals was 6.9%, compared to 1.5% among Canadian hospitals in 1997. In the US, death certificate data suggest mortality rates due to CDAD increased from 5.7 per million population in 1999 to 23.7 per million in 2004. (Gould, Critical Care, 2008)

The reason for the surge has been understood to be the emergence of a new, hypervirulent strain of C. diff that produces up to 20 times more toxin than earlier ones. (C. diff nomenclature will make your brain hurt, but the strain is generally known as NAP1/027/BI, toxinotype III.) But increased virulence doesn’t explain the increased incidence, and the transmission patterns of the new strain have been murky...
An emerging line of inquiry suggests that the transmission patterns become much more clear if you look in a different place for the bacterium’s origin: not in hospitals, but in food.

C. diff has been identified in live pigs, cows and chickens. ...