Unusual rise in children’s pneumonia in England linked to Mycoplasma pneumoniae

In a recent study published in the journal Eurosurveillanceresearchers investigated the unusual rise in emergency department (ED) visits for pneumonia among children aged 5-14 in England from November 2023.

Their findings suggest that this increase, which persisted into the early summer of 2024, is mainly due to bacteria Mycoplasma pneumoniae (MP), even when other seasonal respiratory infections declined.

Quick Contact: Persistent increase in the incidence of pneumonia in children in England, 2023/24. Image Credit: Katerina Kon / Shutterstock

Background

Respiratory infections during winter are a frequent burden on healthcare services in the UK. The UK Health Safety Agency (UKHSA) runs a surveillance program that monitors and reports on respiratory diseases annually to help understand and manage their impact.

Recently, the program identified an unusual increase in pneumonia cases among children between the ages of 5 and 14, prompting research to understand what caused this unexpected increase.

About the study

UKHSA’s program monitors respiratory infections through various systems, including laboratory reports, general practice data and real-time monitoring of ED visits.

The surveillance program includes data from primary care physicians, lab reports, hospital admissions, ED monitoring and telehealth calls, monitoring a range of respiratory markers from the mildest common colds, which are self-limiting, to more serious illnesses such as pneumonia.

This monitoring helps identify mild and severe respiratory illnesses and their impact on the health care system, particularly during peak winter months.

Findings

Starting in November 2023, the number of children aged between 5 and 14 years visiting EDs for pneumonia began to rise above historical expectations, as observed through the UKHSA syndrome surveillance system.

This increased activity continued through December 2023 and did not follow the typical seasonal decline in January 2024. In contrast, the higher-than-expected number of pneumonia-related ED visits remained between February and July 2024.

During this period, there were 2,532 pneumonia-related ED visits in this age group, which, while lower than the 45,003 cases reported in people aged 15 years and older, was still significantly higher than in previous years.

For context, the average number of visits during the same period in 2019-20 and 2022-23 for this age group were, respectively, 607 and 818, highlighting a notable increase in 2024.

Further analysis using data from the Emergency Care Dataset (ECDS) and linked laboratory reports confirmed that, between November 2022 and May 2024, there were 14,096 pneumonia-related ED visits, with 2,334 of these associated with positive microbiological results.

Among the pathogens identified, respiratory syncytial virus (RSV) accounted for 16.6% of cases, influenza A virus for 9.8% and MP for 9.3%.

While RSV and influenza followed their usual seasonal patterns, MP showed a marked increase in early 2024, particularly among children aged 5-14 years, where it was found in 32.2% of pneumonia cases.

In addition, increasing trends in PM infections were seen in children aged between 1 and 4 years, suggesting a wider impact in the younger age groups.

conclusions

The study found a persistent increase in emergency room visits for pneumonia among children between the ages of 5 and 14, largely due to an unusual increase in MP infections during the winter of 2023-24, the first major MP outbreak since the coronavirus disease in 2019 ( covid-19 pandemic.

MP is a common cause of bacterial pneumonia among school-aged children, and while infections are usually mild, some can lead to serious illness.

The study highlights the importance of real-time syndromic surveillance, which has enabled early detection of this trend and timely public health response. The 2023-24 England MP outbreak was part of a global increase in MP cases, but the unusually prolonged period was notable.

The reasons for this prolonged activity remain unclear, but it may be linked to changes in disease transmission patterns due to public health measures related to the pandemic.

In conclusion, the study highlights the value of the UKHSA’s comprehensive respiratory surveillance programme, which includes real-time syndromic surveillance to identify and rapidly investigate unusual disease patterns.

The findings also indicate the need for further research to better understand MP and its public health implications.