Egbe-Nwiyi T N, Igbokwe I O, Onyeyili P A
Department of Veterinary Pathology, University of Maiduguri, P.M.B. 1069, Maiduguri, Borno State, Nigeria.
J Comp Pathol. 2003 Feb-Apr;128(2-3):188-91. doi: 10.1053/jcpa.2002.0599.
Four groups (A, B, C and D) of 10 rats were used to determine the effect of comparatively high doses of diminazene aceturate on diminazene aceturate-resistant Trypanosoma brucei and the pathogenic effect of relapse infection. Group A rats were uninfected (controls) while group B, C and D rats were inoculated intraperitoneally with 0.5 x 10 (6) diminazene aceturate-resistant T. brucei and treated with diminazene aceturate at 14.0, 17.5 and 21.0mg/kg body weight, respectively, on day 14 post-infection (PI) as a single intraperitoneal injection. Prepatent periods and also levels of parasitaemia were comparable in groups B, C and D. Packed cell volume (PCV) decreased in the infected groups by day 14 PI and returned to pre-infection values by day 63 post-treatment (PT). Anaemia was comparable in groups B, C and D. Relapse parasitaemia occurred in six rats in group B on day 70 PT and in five rats in each of groups C and D on day 77 PT. The PCV of the rats with relapse infection decreased progressively up to day 105 PT, when the experiment was terminated, whereas the PCV of rats without relapse did not. The levels of anaemia and parasitaemia on day 14 post-relapse were significantly higher (P<0.05) than the levels obtained on day 14 PI in the same animals. Thus, comparatively high doses of diminazene aceturate failed to cure drug-resistant T. brucei infection in 50-60% of infected rats and relapse infections were more severe than the primary infections before treatment.
使用四组（A、B、C和D），每组10只大鼠，以确定相对高剂量的乙酰甲喹对耐乙酰甲喹的布氏锥虫的影响以及复发感染的致病作用。A组大鼠未感染（作为对照），而B、C和D组大鼠腹腔接种0.5×10⁶ 耐乙酰甲喹的布氏锥虫，并在感染后第14天（PI）分别以14.0、17.5和21.0mg/kg体重腹腔注射一次乙酰甲喹进行治疗。B、C和D组的潜伏期和寄生虫血症水平相当。感染组的红细胞压积（PCV）在感染后第14天下降，并在治疗后第63天（PT）恢复到感染前值。B、C和D组的贫血情况相当。B组有6只大鼠在治疗后第70天出现复发寄生虫血症，C组和D组各有5只大鼠在治疗后第77天出现复发寄生虫血症。复发感染大鼠的PCV在实验终止时的治疗后第105天逐渐下降，而未复发大鼠的PCV则没有。复发后第14天的贫血和寄生虫血症水平显著高于同一动物在感染后第14天的水平（P<0.05）。因此，相对高剂量的乙酰甲喹未能治愈50 - 60%感染大鼠的耐药布氏锥虫感染，且复发感染比治疗前的初次感染更严重。
