Sensitivity to diminazene aceturate and isometamidium chloride of trypanosome isolates from pigs in Enugu North Senatorial Zone, Nigeria

The field control of animal trypanosomosis has relied over the years on two broad strategies: using chemotherapeutic agents on infected animals, and vector control. At present chemotherapy and chemoprophylaxis are the only practical methods available for the control of animal trypanosomosis, but their effectiveness is being threatened by a number of factors, which include increasing parasite resistance, treatment failures and unacceptable toxicity.

The sensitivity of trypanosome isolates from naturally infected pigs in Enugu North Senatorial Zone (18 isolates, comprising 16 T. brucei and 2 T. congolense) was evaluated in mice at two dose levels each of diminazene aceturate (7 and 28 mg/kg body weight) and isometamidium chloride (0.25 and 2 mg/kg) by the infection and treatment method.

Multiple drug resistance was prevalent in the trypanosome isolates, as all 18 isolates (16 T. brucei and 2 T. congolense) tested were resistant to both diminazene aceturate (7 mg/kg b.w) and isometamidium chloride (0.25 mg/ kg b.w,), at the low dose levels tested. Sixteen of the isolates resisted the high dose levels of diminazene aceturate (28 mg/kg b.w), while six isolates were resistant to isometamidium chloride (2 mg/kg b.w).

It was concluded that trypanosome isolates from pigs in the study area exhibited resistance to both diminazene aceturate and isometamidium chloride, the two most commonly used trypanocides in the area. This phenomenon constitutes serious threat to chemotherapeutic control of porcine trypanosomosis in particular and animal trypanosomosis in general in Enugu North Senatorial Zone.

Disclosure of Interest: None Declared.