The Relapse of Single and Mixed Infections of Trypanosoma congolense and Trypanosoma brucei in Red Sokoto Bucks after Treatment with Isometamidium Chloride

Abstract

Field reports by Veterinarians indicate that Isometamidium Chloride used in the treatment of trypanosomosis is not efficacious. This study was designed to determine the efficacy of 2% of this drug in the treatment of single and mixed infections of T. Congoense and T. brucei in Red Sokoto Bucks. Twenty four (24) Red Sokoto Bucks, 8 months - 1 year old were randomly selected and divided into four groups viz (I, II, III, and IV) of six each. These were used to investigate the relapse of infections of single and mixed trypanosome parasites. Group 1 served as un-infected control; Group II and III were inoculated with 2 ml of 1 x 106 Trypanosoma brucei and T. congolense respectively while Group IV were inoculated with 2 ml of 1x106 parasites each of T. congolense and T. brucei . Animals in the infected groups were treated on day 14 post patency with Isometamidium Chloride at the dose rate of 0.5 mg/kg IM. The Bucks were monitored pre-infection, post-infection and post treatment daily for rectal temperature, weekly body weight, PCV, WBC, total proteins and clinical signs. There was aparasitaemia 12hours after treatment. Relapse of the parasites were observed in all infected and treated group of Bucks two weeks post treatment. A buck died in Group II, three goats died in Group III while all goats died in Group IV. Isometamidium Chloride was observed to be efficacious against T. brucei and T. congolense 12 hours after treatment and this was maintained for two weeks when there was a relapse of the parasite. The need for further studies to determine the reason for the relapse is imperative and may necessitate a repeat of treatment two weeks later.