New insights in the outbreak pattern of Mycoplasma pneumoniae

Since a well-documented incidence peak in 2011/12 in European countries, infections due to the cell wall-less bacterium Mycoplasma pneumoniae have gained the increased attention of clinicians, microbiologists and health authorities. Despite the mild or asymptomatic clinical course of most M. pneumoniae infections, the microorganism is responsible for severe interstitial pneumonia and extra-pulmonary complications. Here, we report the time-dependence of 5545 notified cases of laboratory-confirmed M. pneumoniae disease in Saxony from 2001 until June 2014 as measured by serodiagnosis. In parallel, from 2003 until 2012 467 M. pneumoniae-positive respiratory samples or isolated strains were analysed by molecular typing based on sequence differences in the main P1 adhesin of M. pneumoniae. The epidemiological data showed a prolonged outbreak especially in the period 2011-2013. The typing of circulating strains during the outbreak did not support predominance of one of the two major P1 subtypes (mean proportion of subtype 1: 57%) or a change of one to the other subtype during the endemic situation before and during the outbreak period. From the last major outbreak in Europe, we conclude that the notification of M. pneumoniae-positive cases, which is legally required only in Saxony, should be expanded to the whole country, to optimise awareness of this human pathogen and to reflect upon antibiotic therapy.