RESUMO
BACKGROUND: Several outbreaks of pneumococcal pneumonia among shipyard workers have been described. In this study, following a previous report of grouped cases, we aimed to elucidate the features of disease onset. METHODS: We compared the population characteristics of shipyard workers with a confirmed diagnosis of pneumococcal pneumonia (N = 38) to those of workers without pneumonia (N = 53). We compared nine S. pneumoniae strains isolated from patients with pneumonia by capsular serotyping, multi-locus sequence typing, and whole genome sequencing. RESULTS: Shipyard workers with Streptococcus pneumoniae pneumonia were more frequently from Italy (P = 0.016), had at least one underlying condition (P = 0.024), lived on-board the ship (P = 0.009). None of these factors was independent by multivariate analysis. While capsular serotyping enabled us to identify four different serotypes: 4 (n = 5), 8 (n = 2), 9 N (n = 1), and 3 (n = 1), by sequence typing, we distinguished five sequence types (STs): ST801 (n = 4), ST205 (n = 2), ST1220 (n = 1), ST1280 (n = 1), and ST66 (n = 1). Whole genome sequencing confirmed the results obtained by MLST. Genomes of isolates of the same sequence type were similar with ≤80 single-nucleotide polymorphisms. CONCLUSIONS: We confirmed that the onset of pneumococcal infection among shipyard workers was attributable to both a person-to-person spread of single strains of S. pneumoniae and a shift of different strains from commensal to pathogen under favourable conditions (professional exposure, viral infections). Control measures should therefore be implemented by taking into account these features.
Assuntos
Infecções Pneumocócicas , Pneumonia Pneumocócica , Humanos , Tipagem de Sequências Multilocus , Pneumonia Pneumocócica/epidemiologia , Sorogrupo , Sorotipagem , Streptococcus pneumoniae/genéticaRESUMO
We report the third outbreak of pneumococcal pneumonia within one year among workers in European shipyards. During January and February 2020, 37 cases of pneumonia were identified in a shipyard in Marseille, south-eastern France. Outbreak control measures were implemented, including a mass vaccination campaign with 23-valent pneumococcal polysaccharide vaccine targeting all shipyard workers. Given the high mobility of shipyard workers, coordinated responses between European public health institutes are necessary to avoid further outbreaks.