11/16/22 Health Advisory: Increased Pertussis Activity


Whatcom County is experiencing an increase in pertussis (whooping cough) activity. We are asking providers to consider pertussis in the differential for patients with a respiratory tract infection and a known pertussis exposure and/or for patients with paroxysmal cough.


Symptoms usually develop within 7-10 days after exposure but onset can range from 5-21 days. Pertussis typically starts with minor respiratory tract symptoms. This may be followed by intermittent cough, which is often worse at night, and can become paroxysmal. Inspiratory whoop and posttussive vomiting can follow. Illness may be milder in those previously vaccinated. In infants, apnea may be the only symptom.  


Report any suspect or lab-confirmed pertussis case to us within 24hrs (BEFORE test results are available). This facilitates the identification of clusters of disease, enhancing our ability to implement interventions for containment.  If you test or treat for pertussis, report it. 

Communicable Disease Report Line: 360-778-6150  


Treat suspected or lab-confirmed cases and ask that they not attend work, school, or other events until after completing 5 days of appropriate antibiotic or until 21 days after onset of paroxysmal cough if antibiotics are not taken. This is especially important for those in high risk settings such as schools, child cares, and health care.  

Recommended antimicrobial treatment and postexposure prophylaxis for pertussis: 



Test with PCR from NP specimens taken at 0-3 weeks following cough onset. Test sensitivity is greatly diminished after 4 weeks. A negative test does not rule out pertussis in a high probability case.

When collecting a specimen, wear a surgical mask and perform hand hygiene afterwards. Persons within 3 feet of someone ill with pertussis for one hour or those with an obvious exposure (like a cough in the face) are at greater risk for infection. 


The best way to protect against pertussis is with vaccines. Post exposure antibiotic use also protects people who have been exposed. 

CDC and AAP recommend that all household and close contacts receive post-exposure prophylaxis regardless of age or immunization status. Individuals who are receiving chemoprophylaxis do not need to be isolated unless they develop symptoms before completing their antibiotic course.