Reporting & Investigation of Diptheria

Table of Contents

A. Purpose of Surveillance and Reporting

  • To identify and evaluate contacts and provide necessary antimicrobial prophylaxis to prevent further spread of the disease
  • To alert public health authorities to the presence of cases of C. diphtheriae and the potential for increased cases development in the area, particularly given the large number of susceptible adults.
  • To assure early and appropriate treatment with diphtheria antitoxin and antibiotics.
  • To obtain necessary laboratory specimens before antibiotic or antitoxin treatment.

B. Laboratory and Healthcare Provider Reporting Requirements

Iowa Administrative Code 641-1.3 stipulates that the laboratory and the healthcare provider must report any suspected or confirmed cases of diphtheria immediately by phone. The reporting number for IDPH Center for Acute Disease Epidemiology (CADE) is (800) 362-2736, if calling after business hours, call the Iowa State Patrol Office at (515) 323-4360. They will page a member of the on-call CADE staff.

Laboratory Testing Services Available

After communicating with IDPH, contact the University of Iowa State Hygienic Laboratory (SHL) bacteriology department at (319) 335-4500 for further instructions.

C. Local Public Health Agency Follow-up Responsibilities

Case Investigation

Diphtheria follow-up and case investigation is undertaken by the Local Public Health Agency (LPHA), and will be coordinated, if necessary, with the IDPH Bureau of Immunization and Center for Acute Disease Epidemiology (CADE).  

A healthcare provider and a public, private, or hospital clinical laboratory will assist in a disease investigation conducted by the department, or local health department.  A healthcare provider and a public, private, or hospital clinical laboratory will provide the department or local health department with all information necessary to conduct the investigation, including but not limited to medical records, exposure histories, medical histories, contact information, and positive, pending, and negative test results necessary to the investigation.  

Initial Questions to Ask Healthcare Providers and Patients

To assess the likelihood that a suspect case is a true case prior to laboratory testing, LPHA or other public health staff should ask about: 1) symptoms, 2) diphtheria immunization history, 3) recent travel history (where and dates), 4) recent out-of-town visitors (from where and dates), and 5) recent contact with anyone with similar symptoms.