Monday, September 25, 2023

Denmark SSI: No Increase In Serious Non-COVID Infectious Disease Hospitalization Rates Following COVID Infection

 

#17,691


Among COVID survivors we've seen strong evidence that a significant percentage go on to experience a wide range of sequelae following the acute phase of their infection. Repeated reinfections are believed to exacerbate those adverse outcomes (see Nature: Acute and Postacute Sequelae Associated with SARS-CoV-2 Reinfection).

For some, this may mean months of fatigue, shortness of breath, or `mental fog' - while for others it can result in more permanent and debilitating conditions - like diabetes, heart failure, and kidney disease. 

A few, of many blogs on `Long COVID' and other COVID sequelae include: 

AHA: COVID-19 May Trigger New-Onset High Blood Pressure

Viruses Review: Cerebrovascular Disease in COVID-19




 

Considerably less well studied are the effects - if any - of COVID infection on one's ability to fight off subsequent serious (resulting in hospitalization) Non-COVID infectious diseases.  

Today we have study conducted by Denmark's SSI - published last week (behind a paywall) in Clinical Infectious Diseases - which finds no evidence of increased serious infection risks, except possibly in those unvaccinated against COVID.  

It is worth noting that this study looked specifically at adults aged > 50 who were hospitalized for a serious non-COVID infection (i.e. influenza, pneumonia, urinary tract, sepsis, etc.) between Jan 2021 and Dec 2022.  

The study group were first time COVID patients (≥29 days since initial infection), who were subsequently hospitalized for a serious non-COVID infection. They broke this group down into vaccinated, boosted, and unvaccinated.  

With the exception of a relatively small group of unvaccinated cohort members, the study found no evidence of increased hospitalization for serious non-COVID infections among first time COVID cases.

It would be interesting to know if repeated COVID infections affected these results, but for now it is a rare bit of reassuring news on the Long COVID front.  

Since the study is behind a paywall, I've posted the (translated) SSI summary below, followed by a link to the paper.


          (Translated)
Covid-19 infection did not cause more serious infectious diseases

There were no more adults who were hospitalized with serious infectious diseases after being infected with covid-19. This is shown by a new large study from the Statens Serum Institut, where 78,000 hospitalizations have been analysed.

Last edited on September 25, 2023

In a new large register-based study, researchers from the Statens Serum Institut (SSI) have investigated the connection between infection with covid-19 and the risk of hospitalization with other infectious diseases in the time after the acute covid-19 disease was over.

And the conclusion is clear: There were no more hospitalizations with other infectious diseases after infection with covid-19.

The researchers have followed 2.4 million Danes aged 50 or older, in the period from January 2021 to December 2022, where just under 1 million were infected with covid-19.

After the acute covid-19 disease was over, the researchers calculated how many hospitalizations there were for other infectious diseases in the subsequent period and compared this with the frequency in non-covid-19 infected people. Among other things, it was about infectious diseases such as influenza, pneumonia and blood poisoning. 

A total of 78,246 hospitalizations with infectious diseases were analyzed during the study period.

“We found no cause for concern. There were no more hospitalizations with other infectious diseases after infection with covid-19 than expected. On the contrary, it seemed that overall there were slightly fewer," says professor and head of department Anders Hviid, who led the study.

Is the immune system weakened by covid-19?

Covid-19, like other infectious diseases, can be a tough time for the body. There is also some research that points in the direction of an affected immune system in the period after infection with covid-19, which can last for a longer time.

Some studies have also pointed to a weakening of the immune system's ability to defend itself against other infections.

This has naturally given cause for concern when you think about how many have been infected. But there is almost no research that has investigated whether it would actually have an effect in relation to the risk of more serious infections.

The new Danish study is now fixing that. And there was nothing to indicate that a possible weakening of the immune system led to more infections requiring hospitalization in the majority of Danes over 50 who were infected during the study period.

Vaccination was a clear advantage

The researchers also investigated the influence of vaccination status on the time of infection. Here, the researchers observed that the smaller group of Danes who had not received any covid-19 vaccines actually had an increased risk of hospitalization with influenza and serious bacterial infections after infection.

This increased risk was not present in the vaccinated. The booster vaccinated generally had the lowest risks.

"We see once again that although we cannot prevent infection completely with the vaccines, the so-called breakthrough infections are milder. Our results suggest that this does not only apply to the acute covid-19 disease, but also to the possible post-acute adverse effects that have to do with the immune system.” says Anders Hviid.

The study has just been published in the respected scientific journal Clinical Infectious Diseases.


The link to the Abstract follows:


Niklas Worm Andersson, Emilia Myrup Thiesson, Ria Lassaunière, Jørgen Vinsløv Hansen, Anders Hviid

Clinical Infectious Diseases, ciad531, https://doi.org/10.1093/cid/ciad531
Published:
22 September 2023 Article history