Background: Salmonella enterica subsp. enterica serovar Hadar (antigenic formula 6,8:z10:e,n,x) is a serovar of the O:8 (C2-C3) serogroup. S. Hadar is a very common serovar in the U.S. and Europe; associated with turkey and other birds, it is commonly found in ground turkey and chicken meat. In Europe this serovar emerged in the 1971. In England, for example, before 1971 were only eight human cases reported, but by 1979 a total of 1,600 salmonellosis human cases were confirmed to be caused by S. Hadar. Consequent to the S. Hadar emergence, a phage typing scheme was developed, this included 35 recognized phage types. In 2011 an outbreak associated with turkey burgers occurred in the U.S., the outbreak strain showed resistance to several antibiotics typically used to treat salmonellosis (ampicillin, amoxicillin/clavulanate, cephalothin, and tetracycline).
Animal reservoir: the main reservoirs for S. Hadar are turkey flocks and turkey meat. However, chickens, ducks and swine are also source of this serovar. In the U.S this serovar is the most common serovar isolated from turkey.
Geographical distribution: S. Hadar has been isolated in the U.S., where it is among the top ten serovars from non-clinical non-human sources. Serovar Hadar has also been reported in Europe where it is 4th most common serovar isolated from humans. In two countries of Asia (Thailand and China) this serovar has been reported. In Thailand serovar Hadar was found in chicken and duck meat. Reports of acquisition of S. Hadar in travelers from Africa suggest distribution of this serovar in Africa.
Outbreaks: outbreaks of Salmonella Hadar have been identified in the U.S. and Europe, one large outbreak with > 2,000 cases was reported in Spain.
Year |
Location |
Associated source |
Number of cases |
2012 |
US-multistate |
Live poultry |
46 |
2011 |
US-multistate |
Turkey burgers |
12 |
2005 |
Spain |
Pre-cooked chicken |
2138 |
1997 |
Italy |
Roasted rabit |
24 |
1994 |
Italy |
Meat salad |
448 |
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