by Verrest L, Monnerat S, Musa AM, Mbui J, Khalil EAG, Olobo J, Wasunna M, Chu W-Yu, Huitema ADR, Schallig HDFH, Alves F, Dorlo TPC. PLOS Neglected Tropical Diseases 2024, 18(4): e0012078. doi: 10.1371/journal.pntd.0012078
Summary: Some patients treated for visceral leishmaniasis experience disease relapse. To understand why this happens, the authors of this study used Leishmania DNA loads in blood from East African visceral leishmaniasis patients from three clinical trials, treated with five different treatment regimens, to develop a model of parasite dynamics. This model integrates parasite replication in the host, clearance by different drug regimens, and suppression of regrowth by the host immune system post-treatment. This model described the in vivo parasite growth rate in human for the first time and revealed that high blood parasite loads on Days 28 and 56 after start of treatment are an early indication for visceral leishmaniasis relapse, which could serve as a biomarker to predict long-term clinical outcome.