Transient Exposure of Humans to Animal Trypanosomes in Communities Highly Exposed to Tsetse Fly Bite

Abstract Case reports of some Trypanosomes (Trypanosoma congolense, Trypanosoma evansi, Trypanosoma brucei brucei, and Trypanosoma vivax) thought to be natural parasites only to animals have been reported to cause “atypical human trypanosomiasis” (a-HT). This study therefore aimed to provide molecular-based evidence of the circulation of animal trypanosome ITS1 DNA in asymptomatic Ghanaian individuals. A cross-sectional community-based study design was used to collect venous blood and urine samples from 240 human participants. PCR assays were performed targeting Trypanosoma Internal Transcribed Spacer 1 (ITS1) and human apolipoprotein genes. Amplicons were purified and subcloned. Transformed cells were confirmed by PCR. Positive clones were cultured overnight, purified and sequenced. The overall rate of positive tests for trypanosome ITS1 DNA detection was 15.8% (38/240). The highest percentage of trypanosome ITS1 DNA detected (19.2%) was recorded for Zorh, followed by Nkatenkwan (17.9%). Trypanosome parasites found in this study area were Trypanozoon, T. congolense, T. vivaxand T. simiae. There were no mutations in codons 142 or 266 of the ApoL-1 gene in the trypanosome ITS1 DNA-positive subjects. There is a high rate of trypanosome ITS1 DNA detection among humans in the study area. This underscores the need to investigate the impact of animal parasites on human health.