Epidemiology and Infection

Original Papers

Gastrointestinal

A Shiga toxin-producing Escherichia coli O157 outbreak associated with consumption of rice cakes in 2011 in Japan

K. NABAEa1a2 c1, M. TAKAHASHIa3, T. WAKUIa1, H. KAMIYAa4, K. NAKASHIMAa4, K. TANIGUCHIa4 and N. OKABEa4a5

a1 Field Epidemiology Training Program, Infectious Disease Surveillance Centre, National Institute of Infectious Diseases, Tokyo, Japan

a2 Department of Social Medicine, Toho University School of Medicine, Tokyo, Japan

a3 Murayama Public Health Centre, Yamagata Prefecture, Japan

a4 Infectious Disease Surveillance Centre, National Institute of Infectious Diseases, Tokyo, Japan

a5 Kawasaki City Institute of Public Health, Kanagawa, Japan

SUMMARY

In May 2011, an outbreak of Shiga toxin-producing Escherichia coli (STEC) O157 was reported from Yamagata Prefecture, Japan. Investigations, including a case-control study, revealed that the outbreak was linked to two varieties of rice cakes produced by a local manufacturer between 2 and 7 May. Active and passive surveillance identified 136 suspected cases, 142 confirmed cases, 26 asymptomatic cases, and 25 secondary cases. While no environmental samples taken from the manufacturing premises tested positive for STEC, other than a stool sample taken from one employee, on-site and epidemiological investigations indicated that STEC was introduced during the manufacturing process of rice cakes rather than through contamination of raw materials. This was the first reported outbreak of STEC associated with cakes and confectionery in Japan, which indicates that contamination and outbreaks of STEC can occur in any food unless proper precautions are taken.

(Received July 02 2012)

(Revised September 14 2012)

(Accepted October 10 2012)

(Online publication November 06 2012)

Key words

  • Japan;
  • rice cakes;
  • Shiga toxin-producing Escherichia coli

Correspondence

c1 Author for correspondence: Dr K. Nabae, Infectious Disease Surveillance Centre, National Institute of Infectious Diseases, Toyama, 1-23-1 Shinjuku, Tokyo 162-8640, Japan. (Email: k-nabae@umin.ac.jp)

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