Recent trends in the epidemiology of shigellosis in Israel

Abstract

We provide an update on the epidemiology of shigellosis in Israel using data generated by a sentinel laboratory-based surveillance network for the period 1998-2012. The average annual incidence of culture-proven shigellosis was 97/100 000. We estimated that each case of shigellosis accounted for 25 cases in the community indicating the high burden of disease. Orthodox Jewish communities, living in highly crowded conditions and with a high number of children aged <5 years were the epicentre of country-wide biennial propagated epidemics of S. sonnei shigellosis. S. flexneri was the leading Shigella serogroup in Israeli Arabs. S. flexneri 2a and S. flexneri 6 alternated as the most common serotypes. Both S. sonnei and S. flexneri isolates showed high rates of resistance to ampicillin and trimethoprim/sulfamethoxazole and very low rates of resistance to quinolones and third-generation cephalosporins. Shigellosis due to S. sonnei conferred 81% (95% confidence interval 69-89) protection against the homologous Shigella serotype when epidemic exposure re-occurred 2 years later. These data are of value in the process of Shigella vaccine development.

Fig. 1.

Community sentinel laboratories included in the study and their location on the map of Israel. Clalit Health Maintenance Organization (HMO) laboratories in Afula (A) and Haifa (H) representing the North of the country; Clalit HMO laboratory of Soroka Medical Centre in Beer Sheva (S) serving the population in the South; Meuheded HMO laboratory in Jerusalem (M) and Maccabi HMO laboratory of Ramat Gan/Mahoz Dan (D) serving the population in the centre of Israel. The National Reference Centres of the Ministry of Health and the Israel Centre for Diseases Control are located in Jerusalem and Ramat Gan, respectively.

Fig. 2.

Total cases and incidence rates of shigellosis in Israel based on passive reporting on culture-proven cases of disease by microbiological laboratories and physicians, 1951–2012 [13].

Fig. 3

[colour online]. Incidence of shigellosis by Shigella serogroup in the Jewish population served by the sentinel laboratories.

Fig. 4

[colour online]. Incidence of shigellosis by Shigella serogroup in the Arab population served by the sentinel laboratories.

Fig. 5

[colour online]. Incidence of shigellosis in the various age groups of the general population served by the sentinel laboratories.

Fig. 6

[colour online]. Resistance pattern of S. sonnei isolates (n = 3642) to six antimicrobial agents during 2000–2008.

Fig. 7

[colour online]. Resistance pattern of S. flexneri isolates (n = 2173) to six antimicrobial agents during 2000–2008.