乌干达西北部冈比亚锥虫病似乎不存在家养动物储存宿主。
Apparent lack of a domestic animal reservoir in Gambiense sleeping sickness in northwest Uganda.
机构信息
Department of Biochemistry, Makerere University, P.O. Box 7062, Kampala, Uganda.
出版信息
Vet Parasitol. 2012 Jun 8;187(1-2):157-67. doi: 10.1016/j.vetpar.2011.12.005. Epub 2011 Dec 19.
The role played by domestic animals in the transmission of gambiense Human African Trypanosomosis remains uncertain. Northwest Uganda is endemic for Trypanosoma brucei gambiense. Of the 3267 blood samples from domestic animals in four counties examined by hematocrit centrifugation technique (HCT), 210 (6.4%) were positive for trypanosomes. The prevalence of animal trypanosomosis was estimated at 13.8% in Terego County, 4.2% in East Moyo County, 3.1% in Koboko County, and zero in West Moyo County. The trypanosome infection rates varied from 0.2% in goats, 3.5% in dogs, 5.0% in sheep, 7.5% in cattle, to 15.5% in pigs. DNA was extracted from the blood samples by Chelex method, Sigma and Qiagen DNA extraction Kits. A total of 417(12.8%) DNA samples tested positive by polymerase chain reaction (PCR) using T. brucei species specific primers (TBR) indicating that the DNA was of Trypanozoon trypanosomes while 2850 (87.2%) samples were TBR-PCR negative. The T. brucei infection rates based on TBR-PCR were highest in pigs with 21.7%, followed by cattle (14.5%), dogs (12.4%), sheep (10.8%), and lowest in goats with 3.2%, which indicated that pigs were most bitten by infected tsetse than other domestic animals. TBR-PCR detected 6.3% more infected domestic animals that had been missed, and confirmed the 6.4% cases detected by HCT in the field. Statistical analysis done using one-way ANOVA Kruskal-Wallis test (Prism version 5.0) showed no significant difference in trypanosome infections among domestic animals using both HCT and TBR-PCR techniques in the different counties (Confidence Interval of 95%, p-values >0.05). All the 417 trypanosome DNA samples were negative by PCR using two sets of primers specific for the T. b. gambiense specific glycoprotein gene and serum resistance associated gene of T. b. rhodesiense, indicating that they were probably not from the two human infective trypanosomes. Polymerase chain reaction using primers based on ribosomal internal transcribed spacer-1 region (ITS-PCR) resolved the 417 DNA of trypanosome samples into 323 (77.5%) as single trypanosome infections due to T. brucei and 39 (9.4%) mixed infections but missed detecting 55 (13.1%) samples, possibly because of the low sensitivity of ITS-PCR as compared to TBR-PCR. The 31 mixed infections were due to T. brucei (T.b) and T. vivax (T.v); while 8 mixed infections were of T. congolense (T.c) and T. brucei but no mixed trypanosome infections with T. congolense, T. brucei, and T. vivax were detected. Statistical analysis done using one way ANOVA Kruskal-Wallis test (Prism version 5.0) to compare single and mixed trypanosome infections showed no significant difference in trypanosome infections due to single (T.v, T.b, T.c) and mixed (T.v+T.b; T.v+T.c; T.b+T.c; T.v+T.b+T.c) trypanosome species among domestic animals in the different counties using ITS-PCR technique (Confidence Interval of 95%, p-values >0.05). It was concluded that domestic animals in northwest Uganda were probably not reservoirs of T. b. gambiense and there was no infection, as yet, with T. b. rhodesiense parasites.
家畜在传播冈比亚锥虫病中的作用仍不确定。乌干达西北部是布氏冈比亚锥虫的流行区。在四个县用红细胞比容离心技术（HCT）检查的 3267 份家畜血液样本中，210 份（6.4%）被检测出有锥虫。在 Terego 县，动物锥虫病的患病率估计为 13.8%，在东莫约县为 4.2%，在科博科县为 3.1%，在西莫约县为零。锥虫感染率从山羊的 0.2%、狗的 3.5%、绵羊的 5.0%、牛的 7.5%到猪的 15.5%不等。通过 Chelex 方法、Sigma 和 Qiagen DNA 提取试剂盒从血液样本中提取 DNA。使用布氏锥虫种特异性引物（TBR）的聚合酶链反应（PCR）共检测到 417 份（12.8%）DNA 样本呈阳性，表明 DNA 为锥虫属锥虫，而 2850 份（87.2%）样本 TBR-PCR 为阴性。基于 TBR-PCR 的 T. brucei 感染率在猪中最高，为 21.7%，其次是牛（14.5%）、狗（12.4%）、绵羊（10.8%），山羊最低，为 3.2%，这表明猪比其他家畜更容易被感染采采蝇叮咬。TBR-PCR 检测到的感染家畜比 HCT 野外检测到的多 6.3%，并证实了 HCT 检测到的 6.4%病例。使用单向方差分析 Kruskal-Wallis 检验（Prism 版本 5.0）进行的统计分析表明，在不同县使用 HCT 和 TBR-PCR 技术的家畜中，锥虫感染没有显著差异（置信区间为 95%，p 值>0.05）。使用两对针对 T. b. gambiense 特异性糖蛋白基因和 T. b. rhodesiense 血清抗性相关基因的引物进行 PCR 检测，所有 417 份锥虫 DNA 样本均为阴性，表明它们可能不是来自两种人类感染性锥虫。基于核糖体内部转录间隔区-1 区（ITS-PCR）的聚合酶链反应将 417 份锥虫 DNA 样本分为 323 份（77.5%）由于 T. brucei 而发生的单一锥虫感染和 39 份（9.4%）混合感染，但错过了 55 份（13.1%）样本的检测，可能是由于 ITS-PCR 的灵敏度低于 TBR-PCR。31 份混合感染是由于 T. brucei（T.b）和 T. vivax（T.v）；而 8 份混合感染是由于 T. congolense（T.c）和 T. brucei，但未检测到 T. congolense、T. brucei 和 T. vivax 的混合锥虫感染。使用单向方差分析 Kruskal-Wallis 检验（Prism 版本 5.0）进行的统计分析比较了单一和混合锥虫感染，表明在不同县使用 ITS-PCR 技术的单一（T.v、T.b、T.c）和混合（T.v+T.b；T.v+T.c；T.b+T.c；T.v+T.b+T.c）锥虫种的锥虫感染没有显著差异（置信区间为 95%，p 值>0.05）。结论是，乌干达西北部的家畜可能不是布氏冈比亚锥虫的储存宿主，而且目前还没有感染布氏罗得西亚锥虫。
Zotero 插件