Clinician Alert: Pertussis in school aged children in the Portland Metro region

October 22, 2019

The Portland Metro region is seeing an increase in pertussis cases among children aged 0 through 9. Clackamas County’s increase is the greatest, with a total of 37 confirmed and suspect cases since July 1st; twice the number reported in the same time period last year. There is evidence of community-wide spread of pertussis throughout the region.     

Please identify and treat cases to stop further spread. If you see a patient with compatible symptoms, especially with a known pertussis exposure:

  • Test with PCR from a nasopharyngeal (not throat) swab and consider presumptively treating. PCR has excellent sensitivity in the first 3 weeks of cough.

  • Do not order Pertussis serology for diagnosis.

  • See the CDC’s page for more details on testing. 

Do not rule out pertussis based on vaccination status. Nearly 30 percent of recent cases are fully up to date on pertussis vaccine. Still, vaccine is the most effective prevention and should be strongly promoted to increase community immunity.

Clearly recommend staying home from school/daycare for a full 5 days after starting azithromycin for suspected or proven pertussis Prophylaxis for high-risk situations is addressed below.

Report suspected pertussis cases to the Metro Area Pertussis Surveillance program (MAPS) at 503-988-8846

More about pertussis

The illness usually begins with cold-like symptoms, such as a runny nose or an irritating cough. The cough can become severe, with violent episodes of coughing, and can last for weeks to months. Sometimes there can be a “whooping” sound in young children, and some people vomit after coughing. Usually, there is no fever.   

Pertussis is spread through respiratory droplets, and infected persons are most infectious during the early URI-like and the first 2 weeks after severe cough onset. The incubation period of pertussis is 4–21 days (average 7-10 days).

Young infants are the most at risk for complications, most common is secondary bacterial pneumonia.  While most of the cases we are seeing are in children age 1-9, infants 0-1 year old remain the focus of prevention efforts. 

Vaccine recommendations are summarized on the CDC’s page. For pregnant women, vaccine recommendations are in each pregnancy, preferably at 27 through 36 weeks gestation in order to protect the infants who are most at risk.

Post-exposure prophylaxis recommendations

Post-exposure prophylaxis with a 5 day course of azithromycin also focuses on the protection of infants.  Antibiotic prophylaxis should be considered within 21 days of exposure for close contacts of confirmed, presumptive, and suspect cases who are:

  • Infants

  • Pregnant women in the 3rd trimester (since they will soon have contact with an infant)

  • All household contacts of a case if there is an infant or a pregnant woman in the 3rd trimester in the household, even if the infant in the household is the case

  • All those attending or working in a childcare setting (i.e., same room) of a case if there is an infant or one of those same third trimester women in the setting

  • Other contacts at the discretion of the local health department.  We are not generally recommending other populations at this time. 


Metro Area Pertussis Surveillance program (MAPS) at 503-988-8846

Clackamas County: 503-655-8411

Multnomah County: 503-988-3406

Washington County: 503-846-3594


CDC information on pertussis

OHA information on investigating and managing cases of pertussis