Epidemiological And Molecular Study Of Bovine Trypanosomiasis In Diyala Province

Abstract

Bovine trypanosomiasis, caused by infection with Trypanosoma species, poses a serious threat to cattle health and results in considerable economic losses in the livestock sector. This study, conducted in Diyala Province, Iraq, aimed to evaluate the prevalence of bovine trypanosomiasis and identify environmental and weather-related factors influencing its spread. It represents the first investigation of Trypanosoma parasites in this region. A total of 5 mL of jugular blood was collected from 550 cattle of varying ages and sexes across different locations in Diyala between July 2024 and May 2025. Giemsa staining of blood showed 7.82% Trypanosoma infection. Thick/thin smear methods found lower rates (1.82-3.45%), with no significant difference between the two techniques (p > 0.05).  A distinct seasonal pattern was noted, with peak infection rates ranging from while  infection rates peaked at 24% during the hot, dry months of July to September and decreased to nearly 0% in December and January. Molecular detection of Trypanosoma species using Kin1 (ITS1) primers identified the parasite in 9 of 36 samples (25.0%). Kin1 The overall infection rate based on Kin1 detection was 25.0%. was determined based on the final reaction volume following parasite amplification, which amounted to 750 bp. Molecular analysis confirmed a 100% sequence identity between the field isolate and a known Trypanosoma congolense type savannah strain, supporting accurate species identification. Comparative BLAST results showed high genetic similarity among isolates from different regions, with minor variations likely linked to geographic factors. Phylogenetic analysis revealed strong monophyly of T. congolense, limited intraspecific diversity, and clear separation from other trypanosomes.