Pertussis, aka Whooping Cough

There has been a significant rise in cases of Pertussis – otherwise known as whooping cough – this year compared to the last two years. So far in 2024, health departments across Australia have reported 10,035 cases, a significant increase from the 2,447 cases recorded in 2023 and the 482 cases reported in 2022*

Here is what you need to know about Pertussis, aka, Whooping Cough.

This blog is written by Dr Linny Kimly Phuong. Dr Linny is a paediatric infectious diseases physician and researcher. She is passionate about communication of accurate and timely health information to communities, and contributes her skills and knowledge in a variety of forums. She is also the proud mummy to a 4-year-old daughter.

What is pertussis?
Pertussis or whooping cough, is caused by a bacteria called Bordetella pertussis. This bacteria can cause inflammation and swelling of the airways. Pertussis is the second most notified vaccine-preventable disease in Australia.

Pertussis causes coughing and can be (but is not always) associated with a ‘whoop’ sound on breathing-in. It is sometimes caused the ‘100-day cough’ because it lasts for so long.

How is it spread?
It is spread by aerosols and droplets from sneezing/coughing. Household contacts are usually the source of infection (in over 50% of cases, the infection has come from a parent).

What is the incubation period?
Pertussis is very contagious. Patients are infectious from the start of their symptoms to about 21 days after onset of cough (if untreated).

Symptoms of Pertussis:
Some people may have mild symptoms- but can still spread infection

• Fever (not common), runny nose, cough
• Coughing fits, sometimes with vomiting
• Apnoeas
• Struggling to breathe
• Fatigue
• Dehydration

Complications:

• Apnoeas (life threatening episodes of pauses in breathing) in babies, especially under 6 months of age
• Pneumonia (lung infection)
• Seizures
• Inflammation of the brain
• Hypoxic encephalopathy (brain injury due to lack of oxygen)
• Death

How is it diagnosed?
Nose or throat culture/PCR or antibody testing (less common).

How can you prevent Pertussis?
Natural infection does not provide long-term protection. Prevention requires vaccination in the form of ‘combination’ vaccines.

• Babies receive pertussis vaccination at 2, 4 and 6 months
• Children receive pertussis booster vaccination at 4 years of age
• Adolescents receive a pertussis booster at 11-13 years of age
• Pregnant women receive pertussis vaccination during their pregnancy between 20-32 weeks gestation (to protect their newborns for the first 6 months of life whilst they are building their own immunity)
• ‘Cocooning’ refers to the strategy of vaccinating all those around a newborn baby, eg) both parents, grandparents and other friends/ relatives who will be in close contact with the baby

Treatment:
Antibiotics of diagnosed patient but also, preventative antibiotics may be prescribed to contacts who meet certain criteria.

Other measures:
Those with confirmed infection need to stay away from
school or work, until they have received 5 days of antibiotics. Children who have not completed their pertussis vaccinations, should follow the schedule.

References
*https://www.theguardian.com/society/article/2024/jun/21/australia-whooping-cough-infections-rise-why-details-booster-shot?CMP=Share_AndroidApp_Other
1. Australian Immunisation Handbook- Pertussis (whooping cough)-
https://immunisationhandbook.health.gov.au/contents/vaccine-preventable-
diseases/pertussis-whooping-cough
2. Better Health Channel- Pertussis-
https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/whooping-cough
3. RCH Clinical Practice Guidelines- Pertussis-
https://www.rch.org.au/clinicalguide/guideline_index/whooping_cough_pertussis/