Since January 2014, an outbreak of Shigella sonnei-related shigellosis has been observed in the Île-de-France region. This outbreak primarily affects children attending religious schools, most of which are located in Paris. Shigellosis is a disease characterized by diarrhea, fever, and severe abdominal pain following an incubation period of 1 to 3 days. Some cases of diarrhea can be severe and require hospitalization. Shigella is highly pathogenic, as even a very small number of microorganisms is sufficient to cause infection.