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ABSTRACT: Background
Since pastoralists in South Darfur, Sudan, had complained about lack of albendazole (ABZ) efficacy to control nematodes in goats, the frequency of infection with gastrointestinal helminths was studied before in vivo faecal egg count reduction tests (FECRT) were conducted using ABZ orally either at the dose recommended for sheep, 5?mg/kg body weight (bw) or at 10?mg/kg bw. Experiments included goats naturally infected with gastrointestinal nematodes or experimentally infected with local Haemonchus contortus isolates. Three study areas (Nyala, Beleil and Kass) were visited in autumn or winter.Results
Out of 478 screened goats, 82.4% were infected with gastrointestinal helminths and 82% were shedding eggs of strongyle nematodes with 90% of the strongyle larvae representing Haemonchus spp. A FECRT using naturally infected goats (n?=?225: 71 untreated, 104 and 50 treated with 5 and 10?mg ABZ/kg bw, respectively) detected reduced ABZ efficacy in Nyala and Kass. Paired and unpaired FECRT calculations detected reductions of 72-92% with samples taken at 8 days post treatment with 5?mg ABZ/kg bw and of 85-94% with 10?mg ABZ/kg bw. The FECRT based on day 14 post treatment samples showed reductions of 69-77% with 5?mg/kg and of 75-87% with 10?mg ABZ/kg bw. In Beleil, ABZ efficacy was 95%. In the egg hatch test EC50 values for Nyala and Kass ranged from 0.12-0.24??g thiabendazole/ml, corresponding to benzimidazole resistant phenotypes. Only Haemonchus spp. larvae were present after treatments in coprocultures. When the efficacy was evaluated experimentally using isolates of H. contortus from Nyala and Kass, the 5?mg ABZ/kg dose revealed reductions of 76-78% on day 8 and of 62-70% on day 14 with the unpaired method. Using 10?mg ABZ/kg, the FECR was still only 77-82%.Conclusions
Both, in vivo and in vitro methods detected resistant H. contortus populations in goats from South Darfur State. The time point 14?days post treatment was more sensitive for detection of ABZ resistance than 8?days post treatment. This is the first report on the occurrence of anthelmintic resistance in Sudan confirming that anthelmintic resistance selection is occurring in African subsistence farming systems.
SUBMITTER: Mohammedsalih KM
PROVIDER: S-EPMC6549335 | biostudies-literature | 2019 Jun
REPOSITORIES: biostudies-literature
Mohammedsalih Khalid M KM Khalafalla Amna A Bashar Ahmed A Abakar Adam A Hessain Abdelhakaim A Juma Fathel-Rahman FR Coles Gerald G Krücken Jürgen J von Samson-Himmelstjerna Georg G
BMC veterinary research 20190604 1
<h4>Background</h4>Since pastoralists in South Darfur, Sudan, had complained about lack of albendazole (ABZ) efficacy to control nematodes in goats, the frequency of infection with gastrointestinal helminths was studied before in vivo faecal egg count reduction tests (FECRT) were conducted using ABZ orally either at the dose recommended for sheep, 5 mg/kg body weight (bw) or at 10 mg/kg bw. Experiments included goats naturally infected with gastrointestinal nematodes or experimentally infected w ...[more]