Subspecific rodent taxa as the relevant host taxonomic level for mammarenavirus host specificity

Mastomys natalensis-borne mammarenaviruses appear specific to subspecific M. natalensis taxa rather than to the whole species. Yet mammarenaviruses carried by M. natalensis are known to spill over and jump hosts in northern sub-Saharan Africa. Phylogeographic studies increasingly show that, like M. natalensis, small mammals in sub-Saharan Africa are often genetically structured into several subspecific taxa. Other mammarenaviruses may thus also form virus-subspecific host taxon associations. To investigate this, and if mammarenaviruses carried by M. natalensis in southern Africa are less prone to spill-over, we screened 1225 non -M. natalensis samples from Tanzania where many small mammal taxa meet. We found mammarenavirus RNA in 6 samples. Genetic/genomic characterisation confirmed they were not spill-over from M. natalensis. We detected host jumps among rodent tribe members and an association between mammarenaviruses and subspecific taxa of Mus minutoides and Grammomys surdaster, indicating host genetic structure may be crucial to understand virus distribution and host specificity.

Automated summary

Mastomys natalensis-borne mammarenaviruses show a preference for subspecific taxa rather than the entire species. These viruses can spill over and jump hosts in northern sub-Saharan Africa. This study found evidence of mammarenaviruses in non-M. natalensis samples from Tanzania, indicating the possibility of virus-subspecific host taxon associations. Host jumps were observed among rodent tribe members, suggesting that host genetic structure is important for understanding virus distribution and host specificity.