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Mycoplasma pneumoniae Infections in France: Update as of January 21, 2024

Santé publique France has published a summary report on trends in key indicators as of January 21, 2024, following the increase in Mycoplasma pneumoniae infections in France reported in November 2023.

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Find here all the updates on Mycoplasma pneumoniae infections published by Santé publique France.

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In France, in late November 2023, an unusual increase in the number of respiratory infections caused by M. pneumoniae was identified following reports of clusters of cases in schools and reports from clinicians in various regions of several hospitalized cases. Following these field reports, investigations were conducted to confirm the increase in the number of cases and monitor the situation by mobilizing several partners and data sources (clinical, microbiological, epidemiological) in both community and hospital settings.

Initial situation reports were published based on indicators from the SOS Médecins and Oscour® networks, hospital laboratory networks (RENAL), and community laboratory networks (3Labos), as well as monitoring of macrolide resistance profiles by the Bordeaux University Hospital. This summary presents the trends in the main available indicators up to January 21, 2024 (week 03-2024).

Key Points as of January 21, 2024

  • After more than three years of very low circulation levels amid the COVID-19 pandemic, there has been a resurgence of Mycoplasma pneumoniae infections linked to the lifting of public health measures and a decline in the population’s immunity against the infection.

  • Following reports of an unusual increase in the number of respiratory infections caused by M. pneumoniae in schools and hospitals, monitoring of the situation began in November 2023 through the establishment of a multi-source system coordinated by Santé publique France in collaboration with several networks and data sources (clinical, microbiological, epidemiological) in both community settings and hospitals.

  • A sharp increase in emergency care visits for pneumonia among children and young adults from late October 2023 (Week 43) through late December (Week 52), whether in community settings during SOS Médecins visits and consultations or in hospital emergency departments within the Oscour® network.

  • The proportion of emergency department visits for bacterial pneumonia at the end of December (Week 52) among those aged 15–44 and 5–14 far exceeded the values observed during previous epidemics, with levels nearly two and four times higher than the average values for the 2015–2020 reference period in these age groups.

  • The PCR detection rate for M. pneumoniae in hospitals has risen sharply since November (Week 44), reaching, by mid-December (Week 50), a positivity rate nearly six times higher than that observed during the same period in 2019.

  • Few strains resistant to macrolides (first-line antibiotic treatment) were found among samples analyzed between weeks 27/2023 and 02/2024.

  • As of January 21, 2024, indicators in S03 showed a trend toward stabilization or decline, though levels remained very high.