Reporting & Investigation of Polio

Table of Contents

A. Purpose of Surveillance and Reporting

  • To distinguish between wild-type and vaccine-associated polio and to identify susceptible people exposed to wild-type polio.

  • To maintain indigenous transmission rates of wild-type poliovirus at zero.

  • To identify cases of VAPP that might occur secondary to immunization with OPV given in another country.

B. Laboratory and Healthcare Provider Reporting Requirements

Iowa Administrative Code 641-1.3(139) stipulates that the laboratory and the healthcare provider must report any suspected or confirmed cases of polio immediately. The reporting number for IDPH Center for Acute Disease Epidemiology (CADE) is (800) 362-2736. If after business hours, call IDPH at the same number and instructions will be given on how to reach on-call 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.

The likelihood of poliovirus isolation is highest from stool specimens, intermediate from pharyngeal swabs, and very low from blood or spinal fluid.  The isolation of poliovirus from stool specimens contributes to the diagnostic evaluation but does not constitute proof of a causal association of such viruses with paralytic poliomyelitis.  Isolation of virus from the cerebrospinal fluid (CSF) is diagnostic but is rarely accomplished. 

To increase the probability of poliovirus isolation, at least two stool specimens and two throat  swabs should be obtained 24 hours apart from patients with suspected poliomyelitis as early in the course of the disease as possible (i.e., immediately after poliomyelitis is considered as a possible differential diagnosis), but ideally within the first 14 days after onset of paralytic diseased.  Specimens should be sent to the State Hygienic Lab. 

C.  Local Public Health Agency Follow-up Responsibilities

Polio follow-up and case investigation is undertaken by the Local Public Health Agency (LPHA) and will be coordinated if necessary with IDPH Bureau of Disease Prevention and Immunization.  

Initial Question to Ask Healthcare Provider and Patient

In order to assess the likelihood that a suspect case is a true case prior to laboratory testing, LPHA and/or other public health staff helping in the investigation should ask about:

  1. clinical information,
  2. polio immunization history of case and close contacts,
  3. pertinent medical history including underlying illness/immunosuppression,
  4. membership in religious/social group that might refuse immunization,
  5. country of origin and length of residence in US,
  6. recent history of travel (where and dates),
  7. whether there were any recent out-of-town visitors (from where and dates), and
  8. whether occupation entails handling of specimens that might contain poliovirus (e.g., lab work).