Tuesday, 13 March 2012

MRSA in Pig Farmers and Spouses


A major conference is under way in the USA, with a couple of talks given by Tara C Smith, yesterday.

More will be to come later, but meantime, the opening and concluding paragraphs from Maryn McKenna's lengthy "semi live" report are given below.

The writer's years of questioning the true situation in Britain was clearly justified and in the interests of pig farmers and their families. Meat workers, and veterinarians are at similar risk.

The whole is available here


Staph In Pigs And Pig Farmers: The Latest Reports (ICEID 1)

By Maryn McKenna Email Author March 12, 2012 |  11:20 pm

A quick recap: MRSA, drug-resistant staph, was first a hospital infection (starting in 1961), then spread into a broad “community MRSA” epidemic in people who have no connection to hospitals or healthcare (since about 1996) — and then sparked a third epidemic of “livestock-associated” MRSA, slightly different from the previous two and first identified (in 2004) in the families of Dutch pig-farmers. LA-MRSA — or more familiarly “pig MRSA,” though swine agriculture understandably dislikes the term — spread through the European Union, crossed to Canada in 2007, and in 2009 was identified in Iowa pigs and pig farmers by the research team led by Tara C. Smith, PhD, at the University of Iowa....

...In their participants, Smith said, the Iowa team has so far found carriage, without symptoms, of staph that is resistant to tetracycline, and also staph that is multi-drug resistant, though not necessarily to methicillin and other beta-lactam antibiotics — making it both resistant and yet technically MSSA. (Similar to these meat samples.) Farmers raising cattle were somewhat more likely to be carrying resistant staph, and those raising swine were three to four times more likely to be.

The strains are still being analyzed, she said, but so far the most common type of MRSA they have found is the community strain; farmers are also carrying hospital, community and livestock-associated types that are MSSA but still resistant to several antibiotics. As part of the study, they are following up with farmers to see if the strains they are carrying cause infections. So far, five farmers have reported back, two of them with repeat infections; six of the infections have been MSSA and one MRSA. One sample from an infection has been analyzed so far and found to be ST398, the livestock strain, and while not MRSA, resistant to three antibiotics: tetracycline, levaquin, and the combination trimethoprim-sulfamethoxazole.

With much more work to go, the team can say this much, Smith said: “We are seeing livestock-associated staph in this cohort, we are seeing it in spouses as well, and we are seeing that carriage of staph turn into infections.”