Wednesday, November 29, 2023

Denmark SSI Declares A Mycoplasma Pneumonia Epidemic


While all eyes remain firmly fixed on China's outbreak of respiratory illnesses - which are said to be a mixture of flu, RSV, COVID, and Mycoplasma Pneumonia (MP) - there are reports of upticks in MP in other countries around the globe as well. 

Last week the Netherlands reported (see FluTrackers thread) what they described as a`. . .  striking number of children and young people with pneumonia.' (see NIVIL chart below).


Today Denmark's SSI has released a similar report (see below), declaring that Mycoplasma Pneumonia has now reached an epidemic level. 

First their statement, after which I'll return with a postscript.
There is an epidemic of mycoplasma infections - also known as cold pneumonia

Since the summer, there has been an increase in the number of respiratory infections with Mycoplasma pneumoniae, and the occurrence has now reached an epidemic level with significantly more cases than usual.

Last edited on November 29, 2023Mycoplasma

In recent weeks, an increasing number of Danes have been tested positive for Mycoplasma pneumoniae (MP), also known as 'cold pneumonia'.

The number is now so high that it is an epidemic, assesses the Statens Serum Institut.

"In the past five weeks, the number of new cases has increased significantly,I and we are now seeing significantly more cases than usual, and that there is widespread infection throughout the country", says senior researcher Hanne-Dorthe Emborg from the Statens Serum Institut.

In week 47, 541 new cases of MP infection were detected, which is more than threefold since week 42, when the number of detected cases was 168. The real number of cases is probably much higher, as not everyone with mild symptoms is tested.

The disease often presents as mild flu-like symptoms with fatigue, headache, sore throat and prolonged dry cough, especially nocturnal cough. The vast majority have a fever, but often not as high a fever as with influenza and other more classic pneumonia. This has given it the nicknames 'cold pneumonia' or 'atypical pneumonia', as regular penicillin has no effect on the infection either.

Epidemics every four years

In Denmark, there have historically been nationwide epidemics of MP infections approximately every four years, and the incidence is typically highest in autumn and early winter.

"Mycoplasma infections come in waves, where the disease affects the groups in the population that have not yet built up immunity. Therefore, it is also typically a disease seen among school children aged 6-12", explains Hanne-Dorthe Emborg.

The most recent epidemic was in 2015-2018, when there was high incidence in three consecutive seasons. Also in 2019 to 2020 - immediately before the covid-19 pandemic - there was a high number of cases, but during the covid-19 pandemic the number of cases fell to an unusually low level due to the shutdowns, explains Hanne-Dorthe Emborg.

"For the past four years, the number of mycoplasma infections has been extremely low, and it is therefore not unusual that we have an epidemic now. We have actually been waiting for it since we closed the country after the covid-19 pandemic", says Hanne-Dorthe Emborg, and adds:

"Precisely because the number has been so low in the past 3.5 years, and there is therefore a group of children who have not built up immunity, we can probably also expect a higher incidence this season than what has been seen during previous MP- epidemics before the pandemic", she says.

However, MP epidemics do not usually result in many hospitalizations and therefore not significant burdens on the healthcare system.

The increase is also seen in other countries

The incidence of MP infections is also currently increasing in many other countries both in and outside Europe. A study with data from several countries in the world has shown that Denmark has the highest number of registered cases, followed by Sweden and Singapore.

In China, an increase in cases of respiratory infections among children has been observed in November, attributed to the lifting of restrictions against covid-19 with the subsequent circulation of known respiratory diseases such as influenza, RSV, covid-19 and MP. The WHO has asked China to share information on the circulating respiratory diseases and is following developments closely, as is the ECDC in Europe.

At Statens Serum Institut, respiratory infections are continuously monitored and updated weekly with figures and interpretations, which you can find here.

Given that epidemics in Europe have a way of turning up on our doorstep after a few weeks, we may see a similar uptick in cases here in the United States or Canada as well.  While concerning, for now we're not seeing any indication that these outbreaks differ from past events.  

Parents, in particular, may want to familiarize themselves with the symptoms and handling of MP. The CDC's FACT SHEET follows.