A lot of people were surprised by the news of a case of diphtheria in Canada this past week.
Some folks were quick to blame the anti-vaccine movement, assuming it was in an unvaccinated child.
News soon came that the child was vaccinated!
“I’ve always been on top of that, I’m a firm believer in immunizations.”
Mother of 10-year-old with diphtheria
What happened next?
The Case of Diphtheria in Canada
They are wrong.
So how did a vaccinated child in Canada get diphtheria?
He has cutaneous diphtheria, not respiratory diphtheria.
What’s the difference?
“Extensive membrane production and organ damage are caused by local and systemic actions of a potent exotoxin produced by toxigenic strains of C. diphtheriae. A cutaneous form of diphtheria commonly occurs in warmer climates or tropical countries.”
Vaccines Seventh Edition
Cutaneous diphtheria occurs on your skin. It is usually caused by non-toxigenic strains of Corynebacterium diphtheriae.
On the other hand, respiratory diphtheria is usually caused by toxigenic strains of Corynebacterium diphtheriae.
The diphtheria vaccine (the ‘D’ in DTaP and Tdap), a toxoid vaccine, covers toxigenic strains. More specifically, it covers the toxin that is produced by toxigenic strains of Corynebacterium diphtheriae. It is this toxin that produces the pseudomembrane that is characteristic of diphtheria.
It was the formation of this pseudomembrane in a child’s airway that gave diphtheria the nickname of the “strangling angel.”
So why the fuss over this case in Canada? They likely don’t yet know if it is a toxigenic strain. If it is, then it could be a source of respiratory diphtheria.
But remember, even if these kids developed an infection with the toxigenic strain of Corynebacterium diphtheriae, those that are fully vaccinated likely wouldn’t develop respiratory diphtheria. Again, it is the toxin that the bacteria produces that cause the symptoms of diphtheria. The vaccine protects against that toxin.
For example, when an intentionally unvaccinated 6-year-old in Spain was hospitalized with severe diphtheria symptoms a few years ago, although many of his friends also got infected, non of them actually developed symptoms because they were all vaccinated.
Diphtheria Is Still Around
Tragically though, especially since diphtheria is still endemic in many countries, we are starting to see occasional lethal cases of diphtheria in many more countries where it was previously under control:
- at least 7 diphtheria deaths in Venezuela this past year
- a family that became infected in South Africa in which at least one child died (August 2017)
- an unvaccinated 3-year-old who died in Belgium (2016)
- a 22-year-old unvaccinated women who died in Australia (2011)
It is even more tragic that diphtheria is not under control in so many more countries.
In 2016, the WHO reported that there were just over 7,000 cases of diphtheria worldwide. While that is down from the 30,000 cases and 3,000 deaths in 2000, thanks to improved vaccination rates, there is still work to be done.
And as this recent case in Canada shows, diphtheria is still around in many more places than we would like to imagine.
What to Know About Diphtheria in Canada
The case of cutaneous diphtheria in Canada is a good reminder that vaccines are still necessary.
More on Diphtheria in Canada
- AAP – 14 Diseases You Almost Forgot About Thanks to Vaccines
- CDC – What Would Happen If We Stopped Vaccinations
- Diphtheria case confirmed at Edmonton elementary school
- Case of diphtheria confirmed at Edmonton elementary school
- Cutaneous diphtheria photo
- Ask the Experts about DTP
- CDC – Diphtheria (PinkBook)
- CDC – Diphtheria (Manual for the Surveillance of Vaccine-Preventable Diseases)
- Study – Diphtheria in the postepidemic period, Europe, 2000-2009.
- Study – Diphtheria in the Russian Federation in the 1990s .
- ECDC – Diphtheria
- WHO – Diphtheria
- WHO – Position Paper on Diphtheria
- WHO – Review of the Epidemiology of diphtheria