Increased Pertussis Activity in Indiana 11/21/14

November 21st, 2014

The Indiana State Department of Health (ISDH) is investigating increased pertussis activity. Thirty-one laboratory-confirmed cases have been identified from October 26-November 20, 2014 in multiple counties across the state. Other ill individuals are under investigation. Several of these cases attend school in different school corporations. Parents are notified when exposures have occurred in group settings (schools, child care centers, etc.) to describe the symptoms of pertussis and the importance of vaccination (of note, school nurses have noted an increase in cough-related illnesses).

Health care providers are encouraged to consider a diagnosis of pertussis in patients with cough illness meeting the clinical case definition (see below) regardless of pertussis immunization status.

All suspect cases of pertussis should be reported immediately to the local health department or to the ISDH at 317-233-7125.

Pertussis Clinical Case Definition

Health care providers are encouraged to consider a diagnosis of pertussis in patients with cough illness. Pertussis is defined as

  • A cough illness lasting at least two weeks with one of the following:
    • paroxysmal cough, inspiratory “whoop,”
    • or post-tussive vomiting, without other apparent cause.
    • (Infected persons who have been immunized may not develop a whoop and may be misdiagnosed.)

Symptoms typically begin 7-10 days following exposure to ill individuals, usually through coughing and sneezing, and follow three stages.

  • In the first stage, an individual may experience cold-like symptoms, including a runny nose or sneezing. A mild, occasional cough may develop as well.
  • During the second stage, the cough becomes more severe with bursts of coughing (paroxysms) that may cause difficulty catching one’s breath (resulting in a “whoop” sound) or vomiting following coughing. The second stage can last as long as 10 weeks.
  • Finally, the cough begins to resolve and become less persistent during the third stage.


Infant with whooping cough:

Adult with whooping cough:

Child with whooping cough: 

Pertussis can occur in individuals who have received all of their childhood vaccinations and/or Tdap.
Pertussis immunity begins to wane over time, so the addition of a pertussis booster dose (Tdap) is important to provide further protection. Infants under the age of one who are unvaccinated or have not completed the routine DTaP series are particularly vulnerable to complications from pertussis. The CDC estimates that half of infants less than one year of age who contract pertussis will be hospitalized. 

Laboratory Testing

Please order culture or PCR from a nasopharyngeal swab sample for cases meeting the clinical case definition for pertussis or those with a cough illness of any duration with exposure to a known pertussis case.

Serologic tests for diagnosis of pertussis have not been validated and are not considered confirmatory for diagnosis. PCR and culture are the preferred methods for pertussis testing. The ISDH Laboratory has PCR and culture kits available for use in testing suspected cases; instructions for obtaining kits are included in the document link below. Please contact Mugdha Golwalkar at 317-233-7125 for specimen authorization prior to sending to the ISDH Laboratory. 

Good video for specimen collection:

Antibiotic Therapy

If you suspect a pertussis case, try to collect a specimen, but do not wait for laboratory confirmation to initiate antibiotic therapy. Prophylactic antibiotic therapy should also be prescribed for all household contacts regardless of whether or not they are symptomatic and regardless of immunization status. For a chart depicting appropriate antibiotic therapy for both cases and contacts, visit

Note that antibiotics will shorten the infectious period of pertussis, but they will not shorten the duration of symptoms unless provided very early in the course of illness.

 Control Measures

  • Symptomatic close contacts should be excluded from work, school, or other public gatherings through 5 days on an appropriate antibiotic. Symptomatic contacts who are not treated should be excluded through 21 days after cough onset.
  • Asymptomatic close contacts should be placed on antibiotics, but they may immediately return to work or school. One exception: inadequately immunized household contacts under the age of 7 years should be excluded through 5 days on antibiotics per the Indiana Communicable Disease Rule (410 IAC 1-2.3).
  • Assess the vaccination status of patients. Children under age 7 years are eligible for the DTaP vaccine, and persons 10 years of age and older are eligible for the one-time Tdap pertussis booster vaccine. Vaccination following exposure will not prevent illness; however, it will help to protect against future exposures. 

Vaccinate Pregnant Women

In February 2013, the Advisory Committee on Immunization Practices (ACIP) recommended that pregnant women receive a dose of Tdap vaccine in the third trimester of each pregnancy.


If you do not provide adult vaccines in your clinic, you may refer them to the DOH (449-7514)

Questions call Deb McMahan, MD