Behnke J M, Chiejina S N, Musongong G A, Nnadi P A, Ngongeh L A, Abonyi F O, Fakae B B
School of Biology, University of Nottingham, University Park, Nottingham NG72RD, UK.
J Helminthol. 2011 Mar;85(1):80-91. doi: 10.1017/S0022149X10000295. Epub 2010 May 12.
A survey was conducted of gastrointestinal nematode infections and trypanosomosis in Nigerian West African Dwarf (WAD) goats from the savanna region of the country. Animals were screened at two markets, Gboko and Akpagher, from the beginning of April until the end of September, coinciding with the end of the dry season and the first 5 months of the wet season. Of 1054 goats that were examined, 80.5% carried gastrointestinal (GI) nematodes belonging to the genera Haemonchus (61.0%), Oesophagostomum (21.0%) and Trichostrongylus (17.9%). Faecal egg counts (FEC) increased very slowly but significantly from April to maximum levels in September, and varied marginally between the two market sources. The majority of goats (68.8 and 70.1% at the two markets) had low FEC not exceeding 50 eggs/g (epg). FEC did not differ significantly between the sexes or between age classes. Packed cell volume (PCV) also declined significantly with month of the study, but was affected by host sex (a significant month x sex interaction) being generally higher in male animals throughout the period. There was a highly significant negative correlation between log₁₀(FEC+1) and PCV, when all other factors had been taken into account. Body condition scores (BCS) also declined with month of the study, but there was a marked difference between the two sexes, with male animals generally showing a greater stability of BCS across the months compared with females. Trypanosome infections were found in only 4% of the goats and only during the rainy season. Most infections (92.86%) were caused by Trypanosoma brucei alone although T. vivax and T. congolense were occasionally detected. Overall, the majority of goats sampled each month maintained generally good body condition (BCS 3.0-5.0), normal or slightly reduced PCV, even when concurrently infected with trypanosomes and GI nematodes. However, four concurrently infected goats showed signs of overt anaemia during periods of peak infection, during the late rainy season, with marked reductions in PCV (< 15%). Two of the infected goats were also in poor body condition with BCS of < 2.0. There was no evidence of additive or synergistic pathogenic effects of the two parasites. These results are discussed in the context of the unexpectedly strong resistance and resilience of the savanna WAD ecotype to its native strains of GI nematode and trypanosome parasites.
对来自尼日利亚热带稀树草原地区的西非矮种（WAD）山羊的胃肠道线虫感染和锥虫病进行了一项调查。从4月初到9月底，在Gboko和Akpagher这两个市场对动物进行了筛查，这与旱季结束和雨季的前5个月相吻合。在检查的1054只山羊中，80.5%携带属于血矛线虫属（61.0%）、食道口线虫属（21.0%）和毛圆线虫属（17.9%）的胃肠道（GI）线虫。粪便虫卵计数（FEC）从4月到9月缓慢但显著增加至最高水平，且两个市场来源之间略有差异。大多数山羊（两个市场分别为68.8%和70.1%）的FEC较低，不超过50个虫卵/克（epg）。FEC在性别或年龄组之间没有显著差异。血细胞比容（PCV）也随着研究月份的增加而显著下降，但受宿主性别影响（显著的月份×性别交互作用），在此期间雄性动物的PCV总体上更高。在考虑了所有其他因素后，log₁₀（FEC + 1）与PCV之间存在高度显著的负相关。身体状况评分（BCS）也随着研究月份的增加而下降，但两性之间存在明显差异，与雌性相比，雄性动物在各月份的BCS总体上表现出更大的稳定性。仅在4%的山羊中发现了锥虫感染，且仅在雨季期间发现。大多数感染（92.86%）仅由布氏锥虫引起，尽管偶尔也检测到了活泼锥虫和刚果锥虫。总体而言，即使同时感染锥虫和胃肠道线虫，每个月采样的大多数山羊总体身体状况良好（BCS 3.0 - 5.0），PCV正常或略有降低。然而，在感染高峰期，即雨季后期，有4只同时感染的山羊出现了明显贫血的迹象，PCV显著降低（< 15%）。其中2只感染山羊的身体状况也很差，BCS < 2.0。没有证据表明这两种寄生虫存在相加或协同致病作用。将结合热带稀树草原WAD生态型对其本地胃肠道线虫和锥虫寄生虫菌株具有意外强大的抵抗力和恢复力这一背景来讨论这些结果。
