Import and transmission of Mycobacterium orygis and Mycobacterium africanum, Norway

Abstract

Abstract Background The aim of the current study was to improve our understanding of the origins and transmission of Mycobacterium africanum (MAF) in Norway. Methods Whole-genome sequences (WGS) were generated for all (n = 29) available clinical isolates received at the Norwegian National Reference Laboratory for Mycobacteria (NRL) and identified as MAF in Norway, in the period 2010–2020. Phylogenetic analyses were performed. Results The analyses indicated several imports of MAF lineage 6 from both East and West African countries, whereas MAF lineage 5 was restricted to patients with West African connections. We also find evidence for transmission of MAF in Norway. Finally, our analyses revealed that a group of isolates from patients originating in South Asia, identified as MAF by means of a commercial line-probe assay, in fact belonged to Mycobacterium orygis. Conclusions Most MAF cases in Norway are the result of import, but transmission is occurring within Norway.

Keywords

• Mycobacterium africanum
• Mycobacterium orygis
• Transmission
• Low-incidence country
• Whole-genome sequencing