Thursday, September 28, 2023

Denmark SSI: Continuing Whooping Cough Epidemic in Denmark

 

Figure 1. Number of detected cases of whooping cough in Denmark 
per month from January 2015 to and including August 2023  

#17,698

Following the global emergence of COVID in early 2020, and the broad implementation of NPIs (Non-pharmaceutical interventions like masks, social distancing, school closures, etc.), regular patterns of common (and sometimes no-so-common) infectious diseases abruptly changed.

The above chart shows the drought in Whooping Cough (Pertussis) cases reported in Denmark from early 2020 until this past summer, when once again cases began to rise (see last July's Denmark SSI Reports Sharp Increase In Pertussis (Whooping Cough) Since May).

This chart is only valid through August, and according to a statement by Denmark's SSI today, the incidence of cases has more than doubled since then. Very large outbreaks tend to occur every 3 to 5 years, with the last ones reported in Denmark in 2019 and 2016.

Today's (translated) update from the SSI follows:

Continuing whooping cough epidemic in Denmark - tenfold increase in the number of cases compared to normal

The number of cases of whooping cough continues to rise, with levels now seen ten times higher than normal.

Last edited on September 28, 2023

Denmark is currently experiencing an epidemic of whooping cough. During the spring and summer, the weekly number of detected cases has increased significantly, and the Statens Serum Institut (SSI) is now seeing levels that are more than ten times higher than normal.

In week 37 alone, 200 cases of whooping cough were detected, and for comparison, the incidence in the period between the two most recent epidemics was on average approximately 20 cases per week.

"We have seen both a rapid and strong increase in whooping cough over the past months, and since whooping cough is highly contagious, it is important to pay attention to minimizing further infection"Senior researcher Tine Dalby from the Department of Infection Epidemiology and Prevention at SSI

Whooping cough is a respiratory infection that is particularly characterized by a course of up to three months with strong coughing fits, often accompanied by howling breathing and vomiting directly after the fits.


Important for pregnant women to be vaccinated

Pertussis vaccination is part of the childhood vaccination programme, and the purpose of the vaccination is to protect infants in particular, as they are at risk of a serious course of the disease. To protect these children as best as possible, pregnant women are recommended to be vaccinated against whooping cough, as infants can only receive their first vaccination at the age of three months, and they are therefore particularly exposed to infection in the first three months of life. By vaccinating the pregnant woman, both mother and child obtain good protection against whooping cough.

The offer to vaccinate pregnant women was reintroduced after a break on 1 August 2023 as a result of the current epidemic.

"It is important that pregnant women get vaccinated against whooping cough to protect their child, especially now that we have an ongoing epidemic. In most other countries in Europe as well as in The USA, Canada and Australia have also introduced vaccination for pregnant women, and there are good experiences both in terms of safety and effectiveness"Senior researcher Tine Dalby
Whooping cough vaccination only provides short-term immunity, and it is therefore not unusual to see epidemics 3-5 years apart. Certain types of antibiotics (macrolides) can be used to shorten the period when there is a risk of passing the infection on to others, but treatment will only have a limited effect on the course of the disease in the individual.

While children and adolescents are most commonly affected, anyone of any age can become infected, which is why, four months ago I got a long overdue Tdap booster (Tetanus, Diphtheria, Pertussis), my first since 1999. 

The CDC's recommendations for Tdap vaccines and boosters can be found at: