Sinyangwe L, Delespaux V, Brandt J, Geerts S, Mubanga J, Machila N, Holmes P H, Eisler M C
Central Veterinary Research Institute, Balmoral, P.O. Box 33980, Lusaka, Zambia.
Vet Parasitol. 2004 Jan 30;119(2-3):125-35. doi: 10.1016/j.vetpar.2003.11.007.
A survey to investigate resistance to drugs used in the treatment of bovine trypanosomosis was conducted in the eastern province of Zambia between 1996 and 1998. A cross-sectional study was conducted in three districts (Petauke, Katete, Lundazi) at 34 village sampling sites selected at random from villages that had shown greater than 6% prevalence of bovine trypanosomosis during an earlier survey. A longitudinal study was conducted in same three districts over a 1-year period. The study sites were chosen from the cross-sectional study and included eight sites showing high trypanosomosis prevalence and where no control activities were recorded. Use was made of parasitological methods, tests of resistance in cattle and mice and isometamidium-ELISA. Overall mean prevalence of trypanosomosis was 14.4, with 96% of infections caused by Trypanosoma congolense. The remainder was caused by Trypanosoma vivax (2%) and Trypanosoma brucei (2%). Tests in mice showed that of the stabilates collected, 24 (34%) were resistant to only isometamidium chloride, 8 (11.3%) were resistant to only diminazene aceturate, 1 (1.4%) was resistant to both drugs, and 38 (53.5%) were sensitive to both drugs. At least 2 out of 27 stabilates tested in cattle appeared to be resistant to trypanocidal drugs, 1 to isometamidium and 1 to diminazene. Isometamidium could be detected in only 63 (4.1%) of 1526 serum samples from cattle in the study. Only 6 (2.8%) of 212 serum samples from trypanosome-infected cattle had serum levels of the drug above 0.4 ng isometamidium per ml serum which is indicative for drug resistance in the infecting parasite population. Although some drug resistance is apparent, diminazene aceturate and isometamidium chloride can still be expected to be effective as a sanative pair in this area in most cases, since not more than 1 stabilate of 71 investigated showed evidence of resistance to both drugs.
1996年至1998年期间，在赞比亚东部省份开展了一项调查，以研究牛锥虫病治疗用药的耐药情况。在三个区（佩陶凯、卡特特、伦达齐）进行了横断面研究，从早期调查中牛锥虫病患病率高于6%的村庄中随机选取34个村庄采样点。在同一三个区进行了为期1年的纵向研究。研究地点从横断面研究中选取，包括8个锥虫病患病率高且未记录防控活动的地点。采用了寄生虫学方法、牛和小鼠的耐药性检测以及异甲基咪啶酶联免疫吸附测定法。锥虫病的总体平均患病率为14.4%，其中96%的感染由刚果锥虫引起。其余由活泼锥虫（2%）和布氏锥虫（2%）引起。小鼠试验表明，在所收集的稳定株中，24株（34%）仅对氯异甲基咪啶耐药，8株（11.3%）仅对乙酰氨基苯脒耐药，1株（1.4%）对两种药物均耐药，38株（53.5%）对两种药物均敏感。在牛身上检测的27个稳定株中，至少有2个似乎对杀锥虫药物耐药，1个对异甲基咪啶耐药，1个对乙酰氨基苯脒耐药。在该研究中，1526份牛血清样本中仅63份（4.1%）能检测到异甲基咪啶。在212份感染锥虫的牛血清样本中，只有6份（2.8%）的药物血清水平高于每毫升血清0.4纳克异甲基咪啶，这表明感染寄生虫群体存在耐药性。尽管存在一些耐药现象，但在该地区，乙酰氨基苯脒和氯异甲基咪啶在大多数情况下仍有望作为治疗组合有效，因为在71个被调查的稳定株中，不超过1个显示出对两种药物均耐药的证据。
