Unfortunately no one in the public knows exactly where though.
According to the Columbia Tribune reported cases of shigellosis is more than 4 times the expected rate in the Columbia area, and most illnesses are linked to child care settings.
The Columbia/Boone County Department of Public Health and Human Services reports 25 cases of shigellosis, also called shigella, occurring in the past two weeks. Spokeswoman Andrea Waner said the department has averaged six cases a year for the past five years.
Waner said most of the cases involve children attending day care. The Missouri Code of State Regulations prohibits her from identifying the locations, she said.
Michelle Baumstark, spokeswoman for Columbia Public Schools, said the district had only one case, several weeks ago. The student was the sibling of a child who was in day care at a location where shigella was reported.
She said because school-age children are toilet trained there isn’t a big concern about the illness spreading in the schools.
A couple of years ago I collaborated with Clemson’s Angie Fraser on a set of USDA NIFA funded food safety and infection factsheets for childcare facilities including using exclusion of ill staff and children as an outbreak control measure. The sheets can be downloaded here and here. Angie just published a bunch of the observation work that led to the the factsheets in the American Journal of Infection Control (abstract below). The work provides some insight on how pathogens might move around a center.
An observational study of frequency of provider hand contacts in child care facilities in North Carolina and South Carolina
American Journal of Infection Control 43 (2015) 107-11
Angela Fraser, Kelly Wohlgenant, Sheryl Cates, Xi Chen, Lee-Ann Jaykus, You Li, Benjamin Chapman
Background: Children enrolled in child care are 2.3-3.5 times more likely to experience acute gastrointestinal illness than children cared for in their own homes. The purpose of this study was to determine the frequency surfaces were touched by child care providers to identify surfaces that should be cleaned and sanitized.
Methods: Observation data from a convenience sample of 37 child care facilities in North Carolina and South Carolina were analyzed. Trained data collectors used iPods (Apple, Cupertino, CA) to record hand touch events of 1 child care provider for 45 minutes in up to 2 classrooms in each facility.
Results: Across the 37 facilities, 10,134 hand contacts were observed in 51 classrooms. Most (4,536) were contacts with porous surfaces, with an average of 88.9 events per classroom observation. The most frequently touched porous surface was children’s clothing. The most frequently touched nonporous surface was food contact surfaces (18.6 contacts/observation). Surfaces commonly identified as high- touch surfaces (ie, light switches, handrails, doorknobs) were touched the least.
Conclusion: General cleaning and sanitizing guidelines should include detailed procedures for cleaning and sanitizing high-touch surfaces (ie, clothes, furniture, soft toys). Guidelines are available for nonporous surfaces but not for porous surfaces (eg, clothing, carpeting). Additional research is needed to inform the development of evidence-based practices to effectively treat porous surfaces.