Reporting & Investigation of Cholera

Table of Contents

A. Purpose of Surveillance and Reporting

  • To identify sources of major public health concern (e.g., contaminated water or a contaminated lot of shellfish) and to stop transmission from such a source.
  • To identify human cases of epidemic strains of V. cholerae to prevent transmission from such individuals.
  • To identify cases and clusters of human illness that may be associated with a bioterrorist event.

B. Laboratory and Healthcare Provider Reporting Requirements

Iowa Administrative Code 641-1.3(139) stipulates that the laboratory and the healthcare provider immediately report any suspected or confirmed case. The reporting number for IDPH Center for Acute Disease Epidemiology (CADE) is (800) 362-2736.  After business hours please call the Iowa State Patrol Office at (515) 323-4360 and they will page a member of the on-call CADE staff.

Report any suspicion of cholera called to your attention. This could take the form of a healthcare provider or laboratory inquiring about cholera testing.  Note: Due to the rarity and potential severity of cholera, IDPH requests information about any suspect or known case of cholera, or any suspected exposure that may be bioterrorism in nature, is immediately reported to IDPH by the Disease Reporting Hotline (800) 362-2736.

Laboratory Testing Services Available 

The University of Iowa State Hygienic Laboratory (SHL) will test stool specimens for the presence of Vibrio cholerae. It will further identify isolates of V. cholerae as serogroup O1. All V. cholerae non-O1 are sent to CDC for serogroup 139 testing. SHL will also confirm and/or further identify isolates of other Vibrio species obtained from stool specimens or other sources.

Additionally, SHL requests that all laboratories submit all isolates of V. cholerae, V. vulnificus and V.parahaemolyticus cultured for further testing to aid in the public health surveillance necessary for this illness.  Blood specimens requiring serologic testing for evidence of recent infection are sent to the Centers for Disease Control and Prevention (CDC).  Contact SHL for submitting blood samples to CDC. For more information about submitting specimens, contact SHL at (319) 335-4500.

SHL can test implicated food items from a cluster or outbreak.  Food is submitted through the local public health department. 

C. Local Public Health Agency Follow-Up Responsibilities

Case Investigation

  1. Case investigation of cholera in Iowa residents will be directed by IDPH Center for Acute Disease Epidemiology (CADE) (due to the rare occurrence of cholera, the primarily imported nature of the disease, and its potential severity). If a bioterrorism event is suspected, IDPH and other response authorities will work closely with LPHA(s) and provide instructions/information on how to proceed.

  2. Following notification to IDPH, the LPHA may be asked to assist in completing a Surveillance Report form by interviewing the case and others who may be able to provide pertinent information. The Iowa Disease Surveillance System (IDSS) is the preferred method of recording investigation information. Much of the information required on the form can be obtained from the healthcare provider or the medical record.

  3. If several attempts have been made to obtain case information, but have been unsuccessful (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 contact IDPH/CADE staff for assistance. Please notify IDPH/CADE at (800) 362-2736 regarding progress on the case and use IDSS for case information data entry.