October 04, 2024
Background
- Pertussis cases have increased in Fraser Health compared to the period from 2020 to 2023. Individuals with no or partially complete immunization against pertussis are at higher risk of getting the illness.
- Pertussis is a vaccine preventable infectious disease which is endemic cyclical in nature. It peaks in activity expected every two to five years. Fraser Health saw the most recent cyclical peak in 2016. The period of low activity likely was prolonged by the pandemic measures. Pertussis activity has not yet returned to pre-pandemic levels.
- We are advising health care providers to maintain high index of suspicion for pertussis when assessing patients presenting with respiratory symptoms.
- Please test and treat suspect cases and symptomatic contacts, taking steps to prevent transmission in health care settings. Please provide prophylaxis to high-risk contacts.
Image 1. Rate of pertussis cases in Fraser Health and in Canada over time (Ref: Communicable Diseases Dashboard, BCCDC, 2024)
Epidemiologic features
Etiology: Pertussis (whooping cough) is caused by Bordetella pertussis, a small, gram-negative coccobacillus.
Clinical presentation: Pertussis typically evolves over three stages.
- Catarrhal (one to two weeks duration; most infectious): Cold-like symptoms with coryza, sneezing, absent/low-grade fever, mild occasional cough that worsens over time.
- Paroxysmal (about three weeks duration; more infectious during first two weeks): Powerful, prolonged coughing spasms (paroxysms) followed by inspiratory whoop or post-cough emesis.
- Convalescent (weeks to months duration; non-infectious): Cough wanes.
- Immunized individuals and older adults or children may have milder or atypical symptoms.
- Infants: Gagging, apnea or gasping are common in the initial stages of illness.
High-risk groups
- Infants younger than one-year-of-age (especially younger than six-months-of-age) – risk of pneumonia, seizures, encephalopathy and death
- Pregnant women in third trimester
Transmission: Highly transmissible through respiratory droplets or by direct contact with respiratory secretions from an infected person. Secondary attack rate (one case leading to more cases among exposed people) among susceptible household contacts can be as high as 80 per cent.
Incubation period: Seven to 10 days (Range of five to 21 days)
What should I do if I suspect my patient has pertussis?
- Ask the patient to wear a medical mask (if tolerated) and clean their hands.
- Follow Infection Prevention and Control Droplet Precautions. A surgical mask, eye protection and additional personal protective equipment based on point-of-care risk assessment (PCRA) are recommended by PICNet.
- Nasopharyngeal swab: Please follow e-Lab Handbook for pertussis NAT/PCR testing guidance.
- Lab requisition: Use the Bacteriology and Mycology Requisition form.
- Treat: Provide appropriate antibiotics if the patient has confirmed pertussis or symptoms and an epidemiological link to a confirmed case. Most appropriate antibiotics include azithromycin, erythromycin, clarithromycin. Trimethoprim-sulfamethoxazole is an acceptable alternative. Please see pages 17-25 of the BCCDC guidelines for details.
- Advise: All suspect and confirmed cases of pertussis should stay home until they complete five days of antibiotic treatment. Without antibiotics, patients are infectious until three weeks from onset of cough. Asymptomatic contacts of cases do not need to be tested or require isolation.
- Report: Report all suspect, probable and tested (but non-lab confirmed) cases to Communicable Diseases team by calling 604-507-5471. The team will follow-up on positive cases and their high-risk close contacts. Lab confirmed cases are automatically reported to Public Health.
How can patients get tested?
Patients with symptoms of pertussis should stay home and call Public Health at (604) 507-5471 before seeking medical care. Public Health can support testing and treatment as appropriate. Patients can be tested by their Family Physicians or at their local Urgent and Primary Care Centre (UPCC).
Who should receive chemoprophylaxis?
- Public Health Communicable Diseases team will advise on chemoprophylaxis for high-risk contacts of positive cases that meet the BCCDC criteria below.
- Infants younger than one-year-of-age (regardless of immunization status)
- Pregnant women in the third trimester
- All household contacts, IF there is an infant younger than one-year-of-age or a pregnant woman in the third trimester in the household.
- All those in a family daycare IF there is an infant younger than one-year-of-age or a pregnant woman in the 3rd trimester in the daycare.
Immunization
- Pertussis immunization is recommended and publicly funded for children, adolescents and unvaccinated or incompletely vaccinated adults.
- In B.C., pertussis vaccine is routinely given at ages two, four, six and 18 months; four to six-years-of-age; and in grade nine.
- Pertussis vaccine is also recommended and provided for free in every pregnancy, regardless of prior immunization history.
- Pertussis immunization is not an alternative to antibiotic treatment against a current exposure.
Resources
For more information about pertussis and the pertussis vaccine, go to:
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