Reporting & Investigation of Shigellosis

Table of Contents

A. Purpose of Surveillance and Reporting

  • To determine whether a case may be a source of infection for others (e.g., a diapered child, child care attendee, food handler, healthcare worker or child care provider) and if so, to prevent further transmission.
  • To identify transmission sources of public health concern (e.g., a restaurant or a commercially distributed food product) and to stop transmission.

B. Laboratory and Healthcare Provider Reporting Requirements

Iowa Administrative Code 641-1.3(139) stipulates that the laboratory and the healthcare provider must report. The preferred method of reporting is by utilizing the Iowa Disease Surveillance System (IDSS).  However, if IDSS is not available, the reporting number for IDPH Center for Acute Disease Epidemiology (CADE) is (800) 362-2736; fax number (515) 281-5698, mailing address:

IDPH, CADE
Lucas State Office Building, 5th Floor
321 E. 12th Street
Des Moines, IA 50319-0075
Postage-paid disease reporting forms are available free of charge from IDPH. 

To request materials please visit the IDPH website.

Laboratory Testing Services Available

All laboratories are required to submit all isolates cultured for further identification to aid in the public health surveillance necessary for this illness and to prevent further transmission. If exclusion testing is needed, testing should be done at SHL. Please work with the IDPH

C.  Local Public Health Agency Follow-up Responsibilities

Case Investigation

Following notification, the LPHA(s) will complete an official investigation by interviewing the case and others who may be able to provide pertinent information. Much of the investigation information required can be obtained from the healthcare provider or the medical record. Investigation information should be entered into the Iowa Disease Surveillance System (IDSS).

Use the following guidelines to complete the investigation:

  1. Record the demographic information, date of symptom onset, symptoms, diagnostic testing, date of specimen collection, laboratory conducting the testing, species identification and serotyping. Please request isolates to be sent to the SHL.
  2. When asking about exposure history (food, travel, activities, etc.), use the incubation period for shigellosis (12–96 hours). Specifically, focus on the period beginning a minimum of 12 hours prior to the case’s onset back to 96 hours before onset.
  3. Record any restaurants at which the case ate during the incubation period, including food item(s) and date consumed. If it is suspected that the case became infected through food, further investigation may be needed
  4. Ask about travel history and outdoor activities to help identify where the case may have been infected.
  5. Ask about the case’s water supply as well as recreational water activities because Shigella may be acquired through water consumption. 
  6. A case history that includes household/close contacts, antimicrobial treatment, pet or other animal contact, child care, and food-handler questions is designed to look for possible exposure and also to assess potential for transmitting and risk to others. Important information from a public health perspective would include child care attendance or employment or food handling.
  7. If repeated attempts to obtain case information have been unsuccessful (e.g., the case or healthcare provider does not return calls or respond to a letter, or the case refuses to divulge information or is too ill to be interviewed), please complete the investigation with as much information as possible.  Please note why any data is not complete. If using IDSS, select the appropriate reason under the Event tab in the Event Exception field.

After compiling the information, enter into IDSS (the preferred method for investigation) or complete the investigation form, attach lab report(s) when available and fax (515) 281-5698 or mail (in an envelope marked “Confidential”) to IDPH Center for Acute Disease Epidemiology.  The mailing address is:

IDPH, CADE
Lucas State Office Building, 5th Floor
321 E. 12th Street
Des Moines, IA 50319-0075