||International links between Streptococcus pneumoniae vaccine serotype 4 sequence type (ST) 801 in Northern European shipyard outbreaks of invasive pneumococcal disease
||R.A. Gladstone, L. Siira, O.B. Brynildsrud, D.F. Vestrheim, P. Turner, S.C. Clarke, S. Srifuengfung, R. Ford, D. Lehmann, E. Egorova, E. Voropaeva, G. Haraldsson, K.G. Kristinsson, L. McGee, R.F. Breiman, S.D. Bentley, C.L. Sheppard, N.K. Fry, J. Corander, M. Toropainen, A. Steens and The Global Pneumococcal Sequencing Consortium
||Faculty of Pharmacy, Siam University, Bangkok 10160
||Vaccine, Volume 40, Issue 7, 11 February 2022, Pages 1054-1060
Gladstone R.A., Siira L., Brynildsrud O.B., Vestrheim D.F., Turner P., Clarke S.C., Srifuengfung S.,… Wolteral N. (2022). International links between Streptococcus pneumoniae vaccine serotype 4 sequence type (ST) 801 in Northern European shipyard outbreaks of invasive pneumococcal disease. Vaccine, 40(7), 1054-1060.
Background : Pneumococcal disease outbreaks of vaccine preventable serotype 4 sequence type (ST)801 in shipyards have been reported in several countries. We aimed to use genomics to establish any international links between them.
Methods : Sequence data from ST801-related outbreak isolates from Norway (n = 17), Finland (n = 11) and Northern Ireland (n = 2) were combined with invasive pneumococcal disease surveillance from the respective countries, and ST801-related genomes from an international collection (n = 41 of > 40,000), totalling 106 genomes. Raw data were mapped and recombination excluded before phylogenetic dating.
Results : Outbreak isolates were relatively diverse, with up to 100 SNPs (single nucleotide polymorphisms) and a common ancestor estimated around the year 2000. However, 19 Norwegian and Finnish isolates were nearly indistinguishable (0–2 SNPs) with the common ancestor dated around 2017.
Conclusion : The total diversity of ST801 within the outbreaks could not be explained by recent transmission alone, suggesting that harsh environmental and associated living conditions reported in the shipyards may facilitate invasion of colonising pneumococci. However, near identical strains in the Norwegian and Finnish outbreaks does suggest that transmission between international shipyards also contributed to those outbreaks. This indicates the need for improved preventative measures in this working population including pneumococcal vaccination.
Keywords: Streptococcus pneumoniae, Pneumococcal, Whole genome sequencing, Outbreak, ST801, Molecular epidemiology, Serotype 4, PCVs, PPV23.
International links between Streptococcus pneumoniae vaccine serotype 4 sequence type (ST) 801 in Northern European shipyard outbreaks of invasive pneumococcal disease
Faculty of Pharmacy, Siam University, Bangkok, Thailand