Pneumococcal pneumonia among shipyard workers: Inside the features of disease onset.
Travel Med Infect Dis 2021;
44:102183. [PMID:
34688890 DOI:
10.1016/j.tmaid.2021.102183]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 09/21/2021] [Accepted: 10/18/2021] [Indexed: 11/17/2022]
Abstract
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.
Collapse