Background: Salmonella enterica subsp. enterica serovar Infantis (antigenic formula 6,7,14:r:1,5) is a serovar of the O:7 (C1) serogroup. S. Infantis is a serovar globally distributed, which is typically found in chickens. In a number of European countries, serovar Infantis is commonly isolated from broiler flocks. Outbreaks caused by S. Infantis have been associated with pet food and treats. In European countries, a multidrug-resistant (MDR) strain of S. Infantis was disseminated; this strain was originally found in broilers in Hungary (Hungarian clone of S. Infantis). Resistant pattern of this Hungarian clone included resistance to: nalidixic acid, streptomycin, sulphonamide, and tetracycline. In Italy, an MDR strain of S. Infantis that showed resistance to ampicillin, chloramphenicol, streptomycin, sulphonamide, tetracycline, kanamycin and trimethoprim/sulfamethoxazole emerged in 2005-06.
Animal reservoir: The main animal reservoirs of serovar Infantis are poultry and swine. In Europe, layer and broiler farms are the major sources of S. Infantis.
Geographical distribution: S. Infantis is widely distributed and a common serovar in a number of countries. In the U.S. and Europe, it ranks among the top ten serovars. S. Infantis has been reported in North America (U.S. and Canada), South America (Argentina, Brazil), Oceania (Australia and New Zealand), Europe (The Netherlands, Finland, Hungary, and Russia), and Asia (Japan).
Outbreaks: Outbreaks linked to poultry and pet food have been reported in the U.S. and Canada.
Year |
Location |
Associated source |
Number of cases |
2013 |
US-multistate |
Live poultry |
125 |
2012 |
US-multistate |
Dry dog food |
49 |
2012 |
US-multistate |
Live poultry |
195 |
1999 |
Canada |
Pig ear dog treats |
35 |
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