Five years on from COVID-19: New research highlights why bacteria causing childhood infection took so long to return post pandemic

Researchers from Cardiff Metropolitan University and University Children’s Hospital Zurich have identified why a bacterium responsible for respiratory tract infections, which disappeared during the COVID-19 pandemic, took significantly longer than other infections to return.

The study – which looked at the bacterium Mycoplasma pneumoniae and represents the most comprehensive analysis of the infection to take place – was recently published in the prestigious scientific journal, The Lancet Microbe.

Mycoplasma pneumoniae (Mycoplasma) is a major cause of respiratory tract infections in children. Although most infections are mild and self-limiting, Mycoplasma can cause severe pneumonia or infections that require hospitalisation.

The report, ‘Global spatiotemporal dynamics of Mycoplasma pneumoniae re-emergence after COVID-19 pandemic restrictions: an epidemiological and transmission modelling study’ involved creating the largest global dataset for Mycoplasma infections following the COVID-19 pandemic – working with 65 diagnostic laboratories, from 29 different countries worldwide.

Dr Mike Beeton is a Reader in Medical Microbiology at Cardiff Metropolitan University and has been co-leading on the research.

Dr Beeton said: “When various control measures, such as social distancing and lock downs were relaxed, many bugs, such as flu and RSV, returned within a few months. However, Mycoplasma did not. For this reason, we wanted to work with other scientists and clinicians across the globe to identify where and when this infection had returned. Our research found Mycoplasma to be largely absent for over three years and it made a substantial re-appearance in many countries at the end of 2023.

“Our research suggests this delay was due to COVID-19 restrictions being 90% effective at initially reducing the spread of Mycoplasma during the early stages of the pandemic. This reduction in the amount of Mycoplasma circulating in the community, in combination with the poor ability to spread from person to person, helps to explain why it took so long for these infections to return.”

Key findings from the report highlight:

• Despite the unprecedently high number of Mycoplasma detections during re-emergence, the study found that fortunately, overall severity and the number of deaths remained low.
• In some regions, nine out of ten Mycoplasma cases were resistant to the first-line of antibiotic treatment. To assess whether resistance patterns had shifted following the bacterium’s re-emergence, the team examined data from multiple countries.
• This study highlights the need for unified global reporting of Mycoplasma to better understand how the number of infections changes over time across different countries.

Dr Beeton continued: “Moving forward, we plan to continue monitoring the number of infections across the globe. This is incredibly important as it will help us alert clinicians and medical professionals to an increase in infection and raise awareness as these bacterial infections will require specific antibiotics, which are not routinely given for typical bacterial lung infections.”

Patrick Meyer Sauteur, Consultant in Pediatric Infectious Diseases and Research Group Leader in Experimental and Clinical Infectious Diseases at Children’s University Hospital Zurich, said: “The number of Mycoplasma cases has been truly historic since testing for this pathogen was introduced. Our study first showed how relevant this pathogen really is worldwide. This global collaborative network will enable international surveillance of Mycoplasma and antimicrobial resistance to inform clinicians about the emergence of future epidemics.”

The full report, ‘Global spatiotemporal dynamics of Mycoplasma pneumoniae re-emergence after COVID-19 pandemic restrictions: an epidemiological and transmission modelling study’ is now available to read in The Lancet Microbe.