Sure kids can visit the farm, but should they be hugging the cows?

Yesterday I wrote about a bunch of schoolkids in Carlisle , U.K. that have been stricken with cryptosporidium, apparently related to so called-educational visits to nearby farms.

Teachers and school leaders said there were lots of precautions and lots of handwashing. So Shane Morris sent me a picture from the May 1, 2009 edition of the Cumberland News, (right) which documented the trip that apparently sickened the kids and included this charming picture, right, of cow-kid cuddling. Did she sanitize her cheek? And who knows what else went on.

Scott Weese of the Worms and Germs Blog wrote this morning that a recent study by Pritchard et al in the Veterinary Record reports that in samples collected from various animals on 31 different farms in U.K., verotoxigenic E. coli, like O157, was found on 61% of premises. Presence of young cattle and, surprisingly, adult pigs were identified as risk factors for finding verotoxigenic E. coli at a location. Verotoxigenic E. coli were most commonly identified in cattle (29%). It wasn’t surprising that cattle, especially young cattle, were the most common carriers based on what we know about the bacterium, but there were impressively high rates of carriage by other species, including sheep (24%), donkeys (15%), pigs (14%), horses (12%) and goats (10%).

On most farms where verotoxigenic E. coli was found, the same strain was identified in different animal species, indicating that this bacterium can spread widely on such premises. This may be because different animal species in petting zoos are mixed together, as opposed to the situation on conventional farms.

(Weese notes: the premises were evaluated following suspicion that they could have been the source of infection of people, so it’s possible that the numbers reported are higher than for the overall population of such farms.)

Weese writes,

“The risk of people acquiring an infection from animals depends more on the degree of contact and the precautions adopted than the prevalence of infection in a particular species.”

Where does cow hugging and possible face-licking rank on the risk scale?

Farm closes in N. Ireland after visitors contract E. coli

About 90 children and staff at three primary schools in south Belfast are to be tested for the E. coli infection after a P1 pupil at Rosetta Primary School was confirmed as carrying the bug.

Pupils at the school recently took part in a school excursion to an open farm near Belfast along with children from Cregagh and Holy Rosary primaries.

The Eastern Health Board said other people who had contracted the infection in recent weeks had some contact with the farm.

Children and pensioners are especially vulnerable to E. coli O157 which is normally found in the intestines of people and cattle and can be passed on by eating infected food and liquid.

Not quite.

E. coli O157 and other verotoxigenic E. coli are found in about 10 per cent of all ruminants — cattle, sheep, goats, deer — and outbreaks have been linked to each.

So while the farm says,

"We are confident that our intensive cleaning programme over the weekend will further reassure the Health and Safety Executive (HSE) on Monday and that we will immediately reopen for business,"

it may not be that simple.

There have been over 20 outbreaks of severe illness from petting zoos — primarily contact with farm animals — in the past decade.

159 people, mainly children, were sickened with E. coli O157:H7 traced to a goat and a sheep at the petting zoo at the 1999 Western Fair in London, Ontario.

Prof. Hugh Pennington of the U.K. has gone so far as to say that children under five (who are more vulnerable because of their still-developing immune systems) should be banned from visiting livestock farms because of the serious risk of acquiring E. coli O157:H7 infection from farm animals. Such a ban already exists in Sweden.

In the fall of 1998, I accompanied one of my four daughters on a kindergarten trip to the farm (left). After petting the animals and touring the crops –I questioned the fresh manure on the strawberries –we were assured that all the food produced was natural. We then returned for unpasteurized apple cider. The host served the cider in a coffee urn, heated, so my concern about it being unpasteurized was abated. I asked: "Did you serve the cider heated because you heard about other outbreaks and were concerned about liability?" She responded, "No. The stuff starts to smell when it’s a few weeks old and heating removes the smell."

There is much to learn from interacting with animals
, farms and the world. The challenge is to do so in a microbiologically safe manner.