Reporting & Investigation of Legionellosis

Table of Contents

A. Purpose of Surveillance and Reporting

To identify sources of public health concern (e.g., a contaminated water source) and to stop transmission from such a source.

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 reporting method is through the Iowa Disease Surveillance System (IDSS). The reporting phone number for Iowa HHS 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) cultures and tests submitted sputum, bronchi-pharyngeal and environmental samples and referred bacterial cultures for Legionella pneumophila.  Clinical specimens and water should be shipped on wet ice in a sterile container.  Cultures should be submitted on either CYE or chocolate agar.  Sampling kits can be obtained from the State Hygienic Laboratory.  For additional information regarding submitting samples or for further information, contact the SHL at (319) 335-4500, or visit: www.shl.uiowa.edu/

The State Hygienic Laboratory will be discontinuing the Legionella Antibody (Total) serology test effective 1 Feb 2015.  There is typically a delay in development of a measurable antibody response that may affect accurate diagnosis for an acute patient.   Recommended testing to perform in lieu of serology are a Legionella culture (performed at SHL) and/or a Legionella urinary antigen test. While definitive diagnosis is made by culture, performing both culture and urinary antigen test are considered the best diagnostic combination. 

C. Local Public Health Agency Follow-up Responsibilities

Case Investigation

A case investigation should be performed for any diagnosed case of Legionellosis in Iowa.

  1. It is the local public health agency (LPHA) responsibility, in conjunction with the hospital infection preventionist, to complete an IDSS Legionellosis case investigation by interviewing the case and others who may be able to provide information. Much of the information required can be obtained from the case’s healthcare provider or the medical record.
  2. Use the following guidelines to assist in completing the IDSS investigation:
    • Record the demographic information and occupation.
    • Complete the “Clinical Info and Diagnosis” section, providing diagnosis, date of symptom onset, whether hospitalized (and associated dates) and outcome of disease. (One use of this section is to distinguish cases of Legionnaires’ disease from Pontiac fever, when possible [e.g., x-ray diagnosed pneumonia indicates Legionnaires’ disease]). The investigator may need to ask the healthcare provider to submit a copy of the medical record or enlist his/her aid in completing these sections of the case report form.
    • Record the case’s exposures during the 2 weeks before illness onset. Ask questions about travel history in order to help identify where the patient became infected.
    • Provide information regarding “Risk Factors” because legionellosis often affects people who have certain conditions or who smoke.
    • If several attempts have been made to obtain case information, but have been unsuccessful (e.g., the case or healthcare provider does not return your calls or respond to a letter, or the case refuses to divulge information or is too ill to be interviewed), please indicate this in the Notes in IDSS. When using IDSS, select the appropriate reason under the Event tab in the Event Exception field.
  3. If not using IDSS, mail (in an envelope marked “Confidential”) to IDPH, Center for Acute Disease Epidemiology (CADE). 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
  4. Institution of disease control measures is an integral part of case investigation. It is the LPHA   responsibility to understand, and, if necessary, institute the control guidelines in the Controlling Spread tab.