EFFICACY OF INCREASING DOSES OF DIMINAZENE DIACETURATE OR ISOMETAMIDIUM CHLORIDE IN TREATMENT OF MICE INFECTED WITH ISOMETAMIDIUM CHLORIDE-RESISTANT TRYPANOSOMA CONGOLENSE

摘要

Mice infected with Trypanosoma congolense resistant to isomet-amidium chloride were treated with increasing doses of diminazene diacerurate (DD) or isometamidium chloride (IC). Forty eight mice used for the study were randomly divided into 8 groups of6 mice each. Groups 1, 2 and 3 were infected with T. congolense and treated with 7, 14 and 28mg.kg~(-1)DD. Groups 4, 5 and 6 were infected with T. congolense and treated with 1, 2 and 4mg.kg~(-1) IC, while group 7 was infected but not treated. Group 8 was the uninfected control. The parasitaemia was zero in all the groups treated with DD and there were no relapses. The parasitaemia was zero in the groups treated with IC but some relapses did occurred. The 4mg.kg~(-1) IC treated group had the longest mean relapse interval of 16.67 ± 1.91 days when compared with 1 and 2mg.kg~(-1) IC of 9.00 ±0.85 and 10.00 ±1.35 days respectively. The packed cell volume (PCV) of the infected untreated group dropped significantly (P<0.05) when compared with other groups starting from day 12 post infection (PI). However, the PCV of IC treated groups further decreased significantly (P<0.05) from day 32 PI following the relapse. The infection led to a significant (P<0.05) loss in weight on days 8 and 16 PI in all the infected groups. However, the DD treatment reversed the weight decreasing effect of the parasite. The infection led to a significant increase in the rectal temperature on day 8 PI, but was reversed following treatment. The results showed that the IC resistant T. congolense was sensitive to DD at all doses tested, but expressed a high level of resistance to IC.