Reporting & Investigation of Giardiasis

Table of Contents

A.  Purpose of Surveillance and Reporting

  • To assess the magnitude of the disease in different areas and among different risk groups.
  • To identify outbreaks as soon as possible.
  • To design implement effective control or prevention methods.

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:

Iowa HHS, CADE
Lucas State Office Building, 5th Floor
321 E. 12th St.
Des Moines, IA 50319-0075

Postage-paid disease reporting forms are available free of charge from the Iowa HHS clearinghouse. Call (319) 398-5133.

Laboratory Testing Services Available

 The University of Iowa State Hygienic Laboratory (SHL) provides testing services for ova and parasites including Giardia from stool specimens.  For additional information, contact the SHL at (319) 335-4500 or visit www.shl.uiowa.edu/.

C. Local Public Health Agency Follow-up Responsibilities

Case Investigation

  1. Case investigation of giardiasis in Iowa residents may be necessary in certain settings where outbreaks are likely to occur (child cares, nursing homes, etc). Follow-up of individual cases is usually not warranted.
  2. Following IDPH notification of an outbreak or cluster of cases, LPHA(s) may be asked to assist in an official investigation. An investigation can be completed by interviewing the case and others who may be able to provide pertinent information. Most of the information required can be obtained from the healthcare provider or the medical record. Use the following guidelines to assist in completing the investigation:
  3. Record “giardiasis” as the disease being reported.
  4. Record the case’s demographic information.
  5. Record the date of symptom onset, symptoms, date of diagnosis, and hospitalization information (if applicable).
  6. When asking about exposure history (food, travel, activities, etc.), use the incubation period range for giardiasis (3-25 days). Specifically, focus on the period beginning a minimum of 3 days prior to the case’s onset date back to no more than 25 days before onset.
  7. Ask questions about travel history, contact with children, and outdoor activities to help identify where the case became infected.
  8. Ask questions about water supply because giardiasis may be acquired through water consumption. 
  9. Household/close contact, pet or other animal contact, child care, and food handler questions are designed to examine the case’s risk of having acquired the illness from, or potential for transmitting it to, these contacts. Determine whether the case attends or works at a child care facility and/or is a food handler.
  10. Discuss the findings with IDPH or mail (in an envelope marked “Confidential”) to IDPH, Center for Acute Disease Epidemiology.  The mailing address is:

Iowa Department of Public Health, CADE
Lucas State Office Building, 5th Floor
321 E. 12th Street
Des Moines, IA 50319-0075