Mycoplasma pneumoniae: gone forever?

Mycoplasma pneumoniae was a common cause of respiratory tract infections before the COVID-19 pandemic, with worldwide incidence of 8·61% from 2017 to 2020, measured by direct test methods.1Meyer Sauteur PM Beeton ML Uldum SA et al.Mycoplasma pneumoniae detections before and during the COVID-19 pandemic: results of a global survey, 2017 to 2021.Euro Surveill. 2022; 272100746Crossref PubMed Scopus (8) Google Scholar However, non-pharmaceutical interventions (NPIs) against COVID-19 drastically lowered the transmission of M pneumoniae. In the short term, the incidence was down to 1·69% between 2020 and 2021. Lower transmission was also observed for other pathogens at the time.1Meyer Sauteur PM Beeton ML Uldum SA et al.Mycoplasma pneumoniae detections before and during the COVID-19 pandemic: results of a global survey, 2017 to 2021.Euro Surveill. 2022; 272100746Crossref PubMed Scopus (8) Google Scholar However, M pneumoniae transmission also showed long-term reductions during periods with relaxed or discontinued NPIs, with an incidence of 0·70% between 2021 and 2022.2Meyer Sauteur PM Chalker VJ Berger C Nir-Paz R Beeton ML Mycoplasma pneumoniae beyond the COVID-19 pandemic: where is it?.Lancet Microbe. 2022; 3: e897Summary Full Text Full Text PDF PubMed Scopus (1) Google Scholar During the same period infections with other pathogens resurged, indicating increased community transmission.2Meyer Sauteur PM Chalker VJ Berger C Nir-Paz R Beeton ML Mycoplasma pneumoniae beyond the COVID-19 pandemic: where is it?.Lancet Microbe. 2022; 3: e897Summary Full Text Full Text PDF PubMed Scopus (1) Google Scholar The low incidence of M pneumoniae led to initiation of the first global prospective surveillance study of M pneumoniae by our international collaborative network.1Meyer Sauteur PM Beeton ML Uldum SA et al.Mycoplasma pneumoniae detections before and during the COVID-19 pandemic: results of a global survey, 2017 to 2021.Euro Surveill. 2022; 272100746Crossref PubMed Scopus (8) Google Scholar, 2Meyer Sauteur PM Chalker VJ Berger C Nir-Paz R Beeton ML Mycoplasma pneumoniae beyond the COVID-19 pandemic: where is it?.Lancet Microbe. 2022; 3: e897Summary Full Text Full Text PDF PubMed Scopus (1) Google Scholar The network was expanded to new countries and sites to track M pneumoniae in real time in the third year after implementation of NPIs against COVID-19 (from April 1, 2022, to March 31, 2023). The prospective global dataset included 42 sites in 23 countries in Europe, Asia, the Americas, and Oceania (appendix pp 6–9). The mean incidence of M pneumoniae detected by PCR during the 12-month study period was 0·82% (SD 2·36; appendix pp 10–12). Overall, M pneumoniae was detected by PCR in only 214 (0·10%) of 212 207 tests (appendix p 13); positive PCR results were reported in Europe and Asia, but not Oceania or the Americas, except for Cuba, where two positive results were found. Detections by IgM and IgG serology were 306 (7·13%) of 4294, and 574 (13·78%) of 4164, respectively (appendix 10–12). National surveillances in Belgium and Finland reported only positive test numbers—194 in Belgium found by direct test methods with the use of various techniques, and 348 in Finland found predominantly with the use of serology—but not the total number of people tested (appendix pp 10–12). These prospective data for M pneumoniae show that, to our knowledge, the only absent respiratory pathogen was M pneumoniae after long periods with discontinued NPIs worldwide. Of the various speculations about the global unprecedented suppression of M pneumoniae infections immediately after the implementation of NPIs,1Meyer Sauteur PM Beeton ML Uldum SA et al.Mycoplasma pneumoniae detections before and during the COVID-19 pandemic: results of a global survey, 2017 to 2021.Euro Surveill. 2022; 272100746Crossref PubMed Scopus (8) Google Scholar most could be ruled out given the sustained absence of M pneumoniae after long periods with discontinued NPIs. A hypothesis concerning a direct biological effect of SARS-CoV-2 on M pneumoniae has not been rejected, but supporting data do not exist. Transient herd immunity from M pneumoniae epidemics between April, 2019, and March, 2020, in several countries in Europe and Asia1Meyer Sauteur PM Beeton ML Uldum SA et al.Mycoplasma pneumoniae detections before and during the COVID-19 pandemic: results of a global survey, 2017 to 2021.Euro Surveill. 2022; 272100746Crossref PubMed Scopus (8) Google Scholar is another hypothesis. Previously collected data indicated an interval of 1–3 years between M pneumoniae epidemics in Europe and Israel.3Beeton ML Zhang XS Uldum SA et al.Mycoplasma pneumoniae infections, 11 countries in Europe and Israel, 2011 to 2016.Euro Surveill. 2020; 251900112Crossref PubMed Scopus (16) Google Scholar Thus, a resurgent peak in Europe would have been expected by March, 2023. We observed declining detections of M pneumoniae-specific IgM and IgG antibodies by serology from 2020 to 2023,1Meyer Sauteur PM Beeton ML Uldum SA et al.Mycoplasma pneumoniae detections before and during the COVID-19 pandemic: results of a global survey, 2017 to 2021.Euro Surveill. 2022; 272100746Crossref PubMed Scopus (8) Google Scholar, 2Meyer Sauteur PM Chalker VJ Berger C Nir-Paz R Beeton ML Mycoplasma pneumoniae beyond the COVID-19 pandemic: where is it?.Lancet Microbe. 2022; 3: e897Summary Full Text Full Text PDF PubMed Scopus (1) Google Scholar consistent with waning herd immunity. Resurgence of M pneumoniae has not yet been observed. If M pneumoniae infections resurge, they might affect the world population,4Nygaard U Hartling UB Nielsen J et al.Hospital admissions and need for mechanical ventilation in children with respiratory syncytial virus before and during the COVID-19 pandemic: a Danish nationwide cohort study.Lancet Child Adolesc Health. 2023; 7: 171-179Summary Full Text Full Text PDF PubMed Scopus (0) Google Scholar, 5Bamford A Whittaker E Resurgence of group A streptococcal disease in children.BMJ. 2023; 380: 43Crossref PubMed Scopus (0) Google Scholar which has not been exposed to M pneumoniae for the past 3 years, and result in an increase in rare severe disease and extrapulmonary manifestations.2Meyer Sauteur PM Chalker VJ Berger C Nir-Paz R Beeton ML Mycoplasma pneumoniae beyond the COVID-19 pandemic: where is it?.Lancet Microbe. 2022; 3: e897Summary Full Text Full Text PDF PubMed Scopus (1) Google Scholar Our continuous surveillance will lead to early detection of a resurgence of M pneumoniae, and will allow a prompt response with adequate management of re-emerging infections. We declare no competing interests. Download .pdf (.43 MB) Help with pdf files Supplementary appendix