Incidence of upper respiratory tract Mycoplasma pneumoniae infections among outpatients in Rhône-Alpes, France, during five successive winter periods

Abstract

In this prospective study, nasal swab samples from patients with acute respiratory infections were evaluated for the presence of Mycoplasma pneumoniae. This PCR-plus-hybridization-based detection was associated with the detection of other viral agents. During the five winter surveillance periods, 3,897 samples were collected by 75 medical practitioners participating in the Groupe Régional d'Observation de la Grippe surveillance network in Rhône-Alpes (France). M. pneumoniae was detected in 283 samples (7.3%); its rate of detection ranged from 10.1 to 2.0% over the five periods, and it was the second most frequently isolated pathogen during the survey, after influenza A. Three high-prevalence winters were observed, yielding an early winter peak of M. pneumoniae infection which was observed in all age groups. No statistically significant difference was detected between rates of infections in the different age groups, but M. pneumoniae infection was significantly related to lower respiratory tract infection during periods of high prevalence. This study defined the frequency of M. pneumoniae detection from nasal swab specimens in patients with acute respiratory infections, confirming its high prevalence and the presence of large outbreaks due to this pathogen.

FIG. 1

Seasonal distribution of collected specimens (curves) and samples positive for M. pneumoniae (bars). The surveillance was stopped between weeks 14 and 40 of each year.

FIG. 2

Seasonal distribution of samples positive for M. pneumoniae (——), RSV (––––), influenza B virus (… …), and mixed infections due to M. pneumoniae and RSV (■) and M. pneumoniae and influenza B virus (▨) during the winter 1992-1993 surveillance.