Author: Richards S, Pagnossin D, Buyugu PS, Manangwa O, Mramba F, Sindoya E, Paxton E, Torr SJ, Ritchie R, Rossi GE, Anyanwu LN, Barrett MP, Morrison LJ, Auty H
Year: 2025
About this Publication:
African animal trypanosomosis (AAT) is largely managed using trypanocides and insecticides. Failure of trypanocide treatment and prophylaxisis is often reported―due to resistance, substandard drug product quality or inappropriate administration. This 1-year observational study, conducted in high-risk AAT areas in the Serengeti District from June 2021-October 2022, examined reasons for trypanocide failure in Tanzania. Purposive sampling targeted herds with high use of the prophylactic trypanocide isometamidium chloride (ISM). Following trypanocide (ISM, diminazene aceturate or homidium) administration, outcome was determined by PCR and direct blood examination. Risk factors for treatment failure were evaluated using a multivariable mixed model. Drug quality was checked using High Performance Liquid Chromatography, A total of 295 trypanocide administrations, predominantly ISM (56%) for prophylaxis (87%), across 630 cattle from 21 farms were monitored over one year. One in three trypanocide administrations were not adequate, and many trypanocide administrations were given to animals that tested negative for trypanosome infection by PCR. Failures occurred in 7% of curative treatments and 44% of prophylactic administrations. Brand of ISM was significantly associated with prophylaxis failure (p = 0.011). Two ISM samples had no detectable ISM isomers, but the remainder of ISM and diminazene samples (n = 46) were satisfactory. Drug counterfeiting, inadequate use of trypanocides, and resistance are all contributing to trypanocide failure, limiting effective AAT control.
Grant: Tryps2
Subject Areas: Research and Development
Diseases: Trypanosomosis
URL https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0012541
Keywords:
AAT, Tanzania, Trypanocide, treatment
Countries:
