|
|||||||||||||||||||||||||||
Humans acquire infection primarily through consumption of contaminated animal food products. Multi-drug resistant Salmonella typhimurium DT104 can be found in a broad range of foodstuffs. Outbreaks in the United Kingdom and Northern Ireland have been linked to poultry, a variety of meats and meat products, and unpasteurized milk. Foods may be contaminated in different ways: meat by feces during the slaughter process, animals with bacteria in its blood at the time of slaughter; milk by feces during the milking process, or by mastitis in the milked cow. In addition to acquiring infection from contaminated food, human cases have also occurred where individuals have had contact with infected cattle. A small proportion of cases may have contracted infection from pets such as cats and dogs, which can also be infected with this strain of Salmonella. Pets probably acquire the infection like humans, in other words through consumption of contaminated raw meat, poultry or poultry-derived products. Cats have been reported to shed S. typhimurium DT104 in feces for twelve weeks or longer after recovery from an acute illness. The cycle may be perpetuated in a barn setting where cats contaminate animal feeds. Finally, humans can get the disease by fecal-oral transmission from another infected person. Who/what is at risk of infection? The persons most at risk of disease caused by Salmonella
typhimurium DT104 are persons at the extremes of age;
the young and the elderly. The very young have poorly developed
microbial gut flora (which is protective in older children
and adults) while the elderly may have waning immune systems
or weak gastric acidity. Most cases are reported in children
less than four years old. However, immunosuppressed individuals
(e.g. those taking anticancer/cytotoxic drugs or high-dose
steroids, or those with HIV infection) are at increased risk
of infection. In addition, people who have consumed raw and
undercooked animal products, unpasteurized milk, and people
caring for infected pets with this strain of Salmonella are
at greater risk of infection with this organism. In the UK
in 1995, it was also demonstrated that persons in close contact
with farm animals infected with S. t. DT104 (e.g. food producers,
livestock handlers) were at greater risk of acquiring S.t.
DT104 infection than the general population. |
|
© Copyright 1999-2007 Department of Microbiology, Mount Sinai Hospital, Toronto, Canada. All rights reserved.
All rights reserved. Last Modified This website has been made possible through an unrestricted educational grant from
Pfizer Canada Inc.
|
|||||||||||||||||||||||||
© Copyright 1999-2007 Department of Microbiology, Mount Sinai Hospital, Toronto, Canada. All rights reserved.
|