20 October 2010
Nontyphoid Salmonella enterica (NTS) is a common cause of foodborne illnesses worldwide. In Israel, the distribution of NTS infections differs from the global epidemiology for NTS by having a larger representation of serogroups C1 and C2 (serovars Virchow, Hadar, and Infantis) in addition to serovars Enteritidis and Typhimurium.
Analysis of annual trends of NTS infections in Israel during 1995–2009 shows a steady decrease in the incidence of these infections, from 86.9 cases/100,000 persons in 1995 to 31.4/100,000 in 2005. During this period, the predominant serovars were Enteritidis, Typhimurium, Virchow, and Hadar, followed by Infantis. Since 2006, annual incidence of NTS has started to increase, rising to44.0 cases/100,000 persons in 2009. This trend coincided with a sharp increase in incidence of serovar. Infantis from 1.2 cases/100,000 persons in 2001 to 14.7/100,000 in 2009, a 12-fold rise. The proportion of serovar Infantis increased from <10% of NTS in 1995–2005 to34% in 2009. Furthermore, this steep increase in serovar Infantis from clinical (human) sources correlated with an elevated frequency of serovar Infantis from poultry that became apparent after 2006.>Serovar Infantis became the predominant serotype in poultry during 2007–2009, while the prevalences of serovars Enteritidis, Typhimurium, Virchow, Bredeney, Newport, and Paratyphi B var. Java decreased. The emerging Salmonella infantis strain comprised 1 genetic clone with a distinct pulsed-field gel electrophoresis profile and a common antimicrobial drug resistance pattern.