Epidemiology and Infection

Original Papers

Gastroenteritis/Food poisoning

Geographical variations in Salmonella incidence in Israel 1997–2006: the effect of rural residency

M. WEINBERGERa1a2 c1, V. AGMONa3, S. YARONa4, I. NISSANa3 and C. PERETZa5

a1 Infectious Diseases Unit, Assaf Harofeh Medical Center, Zerifin, Israel

a2 School of Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel

a3 Government Central Laboratories, Ministry of Health, Jerusalem, Israel

a4 Department of Biotechnology and Food Engineering, Technion – Israel Institute of Technology, Haifa, Israel

a5 School of Public Health, Epidemiology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel

SUMMARY

The overall incidence and serotype distribution of non-typhoid Salmonella (NTS) may vary between different geographical localities. To investigate possible regional differences and the effect of demographic factors, we studied 15 865 episodes of laboratory-confirmed NTS infection in Israel. Using Poisson models we found significant variation in the average annual incidence rate of NTS in 15 administrative sub-districts, which was inversely associated with the percent of rural residency (incidence rate ratio 0·75, 95% confidence interval 0·65–0·86, P < 0·001). Variation was also found in the relative incidence of the most prominent serotypes (Enteritidis, Virchow, Typhimurium, Hadar, Infantis), which was affected by rural residency, the percent of non-Jewish population in the sub-district, and the percent of population aged ≥55 years in the sub-district. Rural residency had a major effect on the epidemiology of salmonellosis in Israel. Future research is required to understand whether decreased incidence in rural areas is an under-detection bias or reflects true differences in NTS illnesses.

(Received May 20 2012)

(Accepted November 07 2012)

(Online publication December 12 2012)

Key words

  • Epidemiology;
  • geographical information systems;
  • Salmonella

Correspondence

c1 Author for correspondence: M. Weinberger, M. D., Head, Infectious Diseases Unit, Assaf Harofeh Medical Center, Zerifin 70300, Israel. (Email: miriw@netvision.net.il)

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