Rossouw, JenniferGeyer, Hermanus D.W.Birkhead, MonicaWilson, DouglasNel, JeremyKarstaedt, Alan S.Haumann, Carel E.Jonker, AnnelizeSahl, Jason W.Wagner, David M.Frean, John A.2026-04-232026-04-232026-02-19Rossouw, J., Geyer, H.D.W., Birkhead, M. et al. 2026, 'Emergence of human and animal melioidosis in southern Africa, 2018–2021', Tropical Medicine and Infectious Disease, vol. 11, no. 2, art. 60, pp. 1-14, https://doi.org/10.3390/tropicalmed11020060.2414-6366 (online)10.3390/tropicalmed11020060http://hdl.handle.net/2263/109738SUPPLEMENTARY MATERIAL : FIGURE S1: maximum-likelihood phylogeny of core-genome SNPs from genomes within the Africa/America clade. Genomes sequenced in the present study are highlighted in red. While the American clade is collapsed in the main text for clarity, here, the expanded topology is shown to display the detailed relationships among genomes from the Americas. DATA AVAILABILITY STATEMENT : The whole-genome sequence data generated in this study have been deposited in the NCBI BioProject database. The datasets are accessible under BioProject IDs PRJNA531080 (S-547), PRJNA577037 (S-553), and PRJNA1366566 (B1290-18, BC1017, S-563, S-569).Melioidosis is increasingly recognised in tropical and subtropical regions worldwide as a serious and potentially fatal bacterial infection affecting humans and animals, acquired from the environment. Until now, human cases of melioidosis had not been reported in Southern Africa. Over a four-year period, we identified three human and two animal cases of melioidosis in South Africa and Namibia. Burkholderia pseudomallei isolates were investigated by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) and whole-genome sequencing (WGS). Phylogenetic analysis demonstrated substantial diversity, suggesting long-term cryptic persistence of the bacterium in the Southern African region. Limited awareness of the disease and inadequate diagnostic capacity likely contribute to its apparent rarity in the region. These findings underscore the urgent need for increased surveillance, improved diagnostics, and greater awareness of melioidosis in Southern Africa to better understand its true epidemiological burden and prevent future cases.en© 2026 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.MelioidosisSouth Africa (SA)Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS)Whole genome sequencing (WGS)Burkholderia pseudomalleiNamibiaArticle