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J A Van Wyk - One of the best experts on this subject based on the ideXlab platform.
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diagnosis treatment and management of haemonchus contortus in small ruminants
Advances in Parasitology, 2016Co-Authors: R B Besier, Neil Sargison, Lewis Kahn, J A Van WykAbstract:Haemonchus contortus is a highly pathogenic, blood-feeding nematode of small ruminants, and a significant cause of mortalities worldwide. Haemonchosis is a particularly significant threat in tropical, subtropical and warm temperate regions, where warm and moist conditions favour the free-living stages, but periodic outbreaks occur more widely during periods of transient environmental favourability. The clinical diagnosis of Haemonchosis is based mostly on the detection of anaemia in association with a characteristic epidemiological picture, and confirmed at postmortem by the finding of large numbers of H. contortus in the abomasum. The detection of impending Haemonchosis relies chiefly on periodic monitoring for anaemia, including through the 'FAMACHA' conjunctival-colour index, or through faecal worm egg counts and other laboratory procedures. A range of anthelmintics for use against H. contortus is available, but in most endemic situations anthelmintic resistance significantly limits the available treatment options. Effective preventative programmes vary depending on environments and enterprise types, and according to the scale of the Haemonchosis risk and the local epidemiology of infections, but should aim to prevent disease outbreaks while maintaining anthelmintic efficacy. Appropriate strategies include animal management programmes to avoid excessive H. contortus challenge, genetic and nutritional approaches to enhance resistance and resilience to infection, and the monitoring of H. contortus infection on an individual animal or flock basis. Specific strategies to manage anthelmintic resistance centre on the appropriate use of effective anthelmintics, and refugia-based treatment schedules. Alternative approaches, such as biological control, may also prove useful, and vaccination against H. contortus appears to have significant potential in control programmes.
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the pathophysiology ecology and epidemiology of haemonchus contortus infection in small ruminants
Advances in Parasitology, 2016Co-Authors: R B Besier, Neil Sargison, Lewis Kahn, J A Van WykAbstract:Abstract The parasitic nematode Haemonchus contortus occurs commonly in small ruminants, and it is an especially significant threat to the health and production of sheep and goats in tropical and warm temperate zones. The main signs of disease (Haemonchosis) relate to its blood-feeding activity, leading to anaemia, weakness and frequently to deaths, unless treatment is provided. Due to the high biotic potential, large burdens of H. contortus may develop rapidly when environmental conditions favour the free-living stages, and deaths may occur with little prior warning. More chronic forms of Haemonchosis, resulting in reduced animal production and eventually deaths, occur with smaller persistent infections, especially in situations of prolonged, poor nutrition. The global distribution of the main Haemonchosis-endemic zones is consistent with the critical requirements of the egg and larval stages of H. contortus for moisture and moderate to relatively warm temperatures, but the seasonal propensity for hypobiosis (inhibition of the fourth-stage larvae within the host) largely explains the common, though sporadic, outbreaks of Haemonchosis in arid and colder environments. The wide climatic distribution may also reflect the adaptation of local isolates to less favourable ecological conditions, while an apparent increase in the prevalence of outbreaks in environments not previously considered endemic for Haemonchosis – especially cold, temperate zones – may be attributable to climatic changes. Although the risk of Haemonchosis varies considerably on a local level, even where H. contortus is endemic, the extensive range of ecological investigations provides a sound basis for predictions of the relative geographical and seasonal risk in relation to climatic conditions.
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production trials involving use of the famacha system for Haemonchosis in sheep preliminary results
Onderstepoort Journal of Veterinary Research, 2008Co-Authors: J A Van WykAbstract:VAN WYK, J.A. 2008 Production trials involving use of the FAMACHA© system for Haemonchosis in sheep: preliminary results. Onderstepoort Journal of Veterinary Research, 75:331–345 In three trials conducted on two separate farms the production of sheep treated for naturally acquired Haemonchosis using the FAMACHA© system of targeted selective treatment (TST) (i.e. to treat only those animals unable to manage unaided in the face of heavy Haemonchus challenge) was compared to that of suppressively drenched sheep in the same flock. As expected by the research team who developed and evaluated the FAMACHA© system, TST did result in some loss in production. However, despite high levels of worm challenge in two of the trials and the fact that the comparison was with suppressive drenching which is not sustainable, the total effect was relatively small in relation to the important advantage of using the TST as regards reduced selection for anthelmintic resistance (AR). Concerning the sustainability of worm control, it is concluded that the development of drug resistance to anthelmintics leaves sheep and goat farmers in South Africa no choice but to use methods of TST such as FAMACHA©. The FAMACHA© system can also be a useful clinical aid for early on-farm detection of AR by farmers; the degree of improvement in the colour of the ocular mucous membrane from pale to red in individually drenched anaemic animals over a period of 7–14 days can give a good indication of the efficacy of the compound(s) used.
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Production trials involving use of the FAMACHA© system for Haemonchosis in sheep : preliminary results
AOSIS, 2008Co-Authors: J A Van WykAbstract:In three trials conducted on two separate farms the production of sheep treated for naturally acquired Haemonchosis using the FAMACHA© system of targeted selective treatment (TST) (i.e. to treat only those animals unable to manage unaided in the face of heavy Haemonchus challenge) was compared to that of suppressively drenched sheep in the same flock. As expected by the research team who developed and evaluated the FAMACHA© system, TST did result in some loss in production. However, despite high levels of worm challenge in two of the trials and the fact that the comparison was with suppressive drenching which is not sustainable, the total effect was relatively small in relation to the important advantage of using the TST as regards reduced selection for anthelmintic resistance (AR). Concerning the sustainability of worm control, it is concluded that the development of drug resistance to anthelmintics leaves sheep and goat farmers in South Africa no choice but to use methods of TST such as FAMACHA©. The FAMACHA© system can also be a useful clinical aid for early on-farm detection of AR by farmers; the degree of improvement in the colour of the ocular mucous membrane from pale to red in individually drenched anaemic animals over a period of 7-14 days can give a good indication of the efficacy of the compound(s) used
M Cuquerella - One of the best experts on this subject based on the ideXlab platform.
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2020Co-Authors: Leticia García-coiradas, J M Alunda, Basilio Valladares, Enrique Martinez, Concepcion De La Fuente, Francisco Angulo-cubillán, M CuquerellaAbstract:Haemonchosis, caused by the abomasal nematode Haemonchus contortus, is a common parasitic disease of sheep. Our previous results showed that a soluble fraction from adult stages of the nematode (p26/23) induced partial protection against challenge. Recombinant DNA technology was applied to obtain a synthetic protein (rHcp26/23). Immunological assays (ELISA, Western blotting, and immunolocalization), using sera from lambs immunized with p26/23, confirmed the identity of the recombinant protein and demonstrated that the synthetic protein is equivalent to the purified protein employed in the previous immunoprophylaxis studies. Vaccination of lambs with 300 μg of rHcp26/23 and Freund's adjuvant elicited a notable specific antibody response. Immunization did not induce any significant protection after challenge with 16000 infective larvae of H. contortus, and comparable values for parasite faecal egg output, packed cell volume, and abomasal parasite burdens were found in vaccinated and control animals
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vaccination of lambs against haemonchus contortus infection with a somatic protein hc23 from adult helminths
International Journal for Parasitology, 2014Co-Authors: Elshaima Mohamed Fawzi, M Cuquerella, Maria Elena Gonzalezsanchez, Maria Jesus Corral, J M AlundaAbstract:A somatic protein from adult Haemonchus contortus (Hc23), the most abundant component in a low molecular weight fraction with known immunizing effect against experimental Haemonchosis, has been purified by immunochromatography. The immunoprophylactic value of Hc23 was tested in groups of 5-6months old Assaf lambs using Al(OH)3 or Escherichia coli lipopolysaccharide+inactivated Propionibacterium acnes as adjuvant and the results compared with uninfected control, uninfected and challenged or infected and challenged lambs. Immunization with Hc23 in either adjuvant elicited significant reductions in fecal egg counts after challenge with 15,000 L3s (70.67%-85.64%, respectively) and reduced (67.1% and 86%) abomasal worm counts (45days post-challenge). Immunized lambs displayed higher peripheral eosinophil counts, were less anaemic and had weight gains than challenged controls. The results suggest that the Hc23 antigen can induce a partially protective response against Haemonchosis in lambs. © 2014 Australian Society for Parasitology Inc.
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immunization against lamb Haemonchosis with a recombinant somatic antigen of haemonchus contortus rhcp26 23
Veterinary Medicine International, 2010Co-Authors: Leticia Garciacoiradas, J M Alunda, Francisco Angulocubillan, Basilio Valladares, Enrique Martinez, Concepcion De La Fuente, M CuquerellaAbstract:Haemonchosis, caused by the abomasal nematode Haemonchus contortus, is a common parasitic disease of sheep. Our previous results showed that a soluble fraction from adult stages of the nematode (p26/23) induced partial protection against challenge. Recombinant DNA technology was applied to obtain a synthetic protein (rHcp26/23). Immunological assays (ELISA, Western blotting, and immunolocalization), using sera from lambs immunized with p26/23, confirmed the identity of the recombinant protein and demonstrated that the synthetic protein is equivalent to the purified protein employed in the previous immunoprophylaxis studies. Vaccination of lambs with 300
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Immunization against Lamb Haemonchosis with a Recombinant Somatic Antigen of Haemonchus contortus (rHcp26/23)
Hindawi Limited, 2010Co-Authors: Leticia García-coiradas, J M Alunda, Basilio Valladares, Enrique Martinez, Concepcion De La Fuente, Francisco Angulo-cubillán, M CuquerellaAbstract:Haemonchosis, caused by the abomasal nematode Haemonchus contortus, is a common parasitic disease of sheep. Our previous results showed that a soluble fraction from adult stages of the nematode (p26/23) induced partial protection against challenge. Recombinant DNA technology was applied to obtain a synthetic protein (rHcp26/23). Immunological assays (ELISA, Western blotting, and immunolocalization), using sera from lambs immunized with p26/23, confirmed the identity of the recombinant protein and demonstrated that the synthetic protein is equivalent to the purified protein employed in the previous immunoprophylaxis studies. Vaccination of lambs with 300 μg of rHcp26/23 and Freund's adjuvant elicited a notable specific antibody response. Immunization did not induce any significant protection after challenge with 16000 infective larvae of H. contortus, and comparable values for parasite faecal egg output, packed cell volume, and abomasal parasite burdens were found in vaccinated and control animals
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immunization against ovine Haemonchosis with three low molecular weight somatic antigens of adult haemonchus contortus
Journal of Veterinary Medicine Series B-infectious Diseases and Veterinary Public Health, 2003Co-Authors: J M Alunda, Francisco Angulocubillan, M CuquerellaAbstract:Individual bands (15) from electroblotted soluble extracts of adult Haemonchus contortus were excised and three peptides of molecular weight ca. 56 (F4), 39 (F8) and 18.5 kDa (F14) used to vaccinate 4-4.5-months-old lambs against the nematode. Immunizing doses from each peptide were administered in 1 ml Freund complete adjuvant (first 50 microg injection) and 1 ml Freund incomplete adjuvant (second and third 50 microg injections) to six lambs. Two weeks after last immunization, animals were challenged with 300 L-3/kg live weight (LW). Lambs were slaughtered 34 days after challenge. Immunization induced a strong antibody response estimated by enzyme-linked immunosorbent assay, whereas no peripheral lymphoproliferative response was observed. Lambs in the F8-vaccinated group showed on average delayed pre-patent period, lower faecal egg counts and reduction of abomasal worm burdens, although the differences were not statistically significant.
J M Alunda - One of the best experts on this subject based on the ideXlab platform.
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2020Co-Authors: Leticia García-coiradas, J M Alunda, Basilio Valladares, Enrique Martinez, Concepcion De La Fuente, Francisco Angulo-cubillán, M CuquerellaAbstract:Haemonchosis, caused by the abomasal nematode Haemonchus contortus, is a common parasitic disease of sheep. Our previous results showed that a soluble fraction from adult stages of the nematode (p26/23) induced partial protection against challenge. Recombinant DNA technology was applied to obtain a synthetic protein (rHcp26/23). Immunological assays (ELISA, Western blotting, and immunolocalization), using sera from lambs immunized with p26/23, confirmed the identity of the recombinant protein and demonstrated that the synthetic protein is equivalent to the purified protein employed in the previous immunoprophylaxis studies. Vaccination of lambs with 300 μg of rHcp26/23 and Freund's adjuvant elicited a notable specific antibody response. Immunization did not induce any significant protection after challenge with 16000 infective larvae of H. contortus, and comparable values for parasite faecal egg output, packed cell volume, and abomasal parasite burdens were found in vaccinated and control animals
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vaccination of lambs against haemonchus contortus infection with a somatic protein hc23 from adult helminths
International Journal for Parasitology, 2014Co-Authors: Elshaima Mohamed Fawzi, M Cuquerella, Maria Elena Gonzalezsanchez, Maria Jesus Corral, J M AlundaAbstract:A somatic protein from adult Haemonchus contortus (Hc23), the most abundant component in a low molecular weight fraction with known immunizing effect against experimental Haemonchosis, has been purified by immunochromatography. The immunoprophylactic value of Hc23 was tested in groups of 5-6months old Assaf lambs using Al(OH)3 or Escherichia coli lipopolysaccharide+inactivated Propionibacterium acnes as adjuvant and the results compared with uninfected control, uninfected and challenged or infected and challenged lambs. Immunization with Hc23 in either adjuvant elicited significant reductions in fecal egg counts after challenge with 15,000 L3s (70.67%-85.64%, respectively) and reduced (67.1% and 86%) abomasal worm counts (45days post-challenge). Immunized lambs displayed higher peripheral eosinophil counts, were less anaemic and had weight gains than challenged controls. The results suggest that the Hc23 antigen can induce a partially protective response against Haemonchosis in lambs. © 2014 Australian Society for Parasitology Inc.
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immunization against lamb Haemonchosis with a recombinant somatic antigen of haemonchus contortus rhcp26 23
Veterinary Medicine International, 2010Co-Authors: Leticia Garciacoiradas, J M Alunda, Francisco Angulocubillan, Basilio Valladares, Enrique Martinez, Concepcion De La Fuente, M CuquerellaAbstract:Haemonchosis, caused by the abomasal nematode Haemonchus contortus, is a common parasitic disease of sheep. Our previous results showed that a soluble fraction from adult stages of the nematode (p26/23) induced partial protection against challenge. Recombinant DNA technology was applied to obtain a synthetic protein (rHcp26/23). Immunological assays (ELISA, Western blotting, and immunolocalization), using sera from lambs immunized with p26/23, confirmed the identity of the recombinant protein and demonstrated that the synthetic protein is equivalent to the purified protein employed in the previous immunoprophylaxis studies. Vaccination of lambs with 300
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Immunization against Lamb Haemonchosis with a Recombinant Somatic Antigen of Haemonchus contortus (rHcp26/23)
Hindawi Limited, 2010Co-Authors: Leticia García-coiradas, J M Alunda, Basilio Valladares, Enrique Martinez, Concepcion De La Fuente, Francisco Angulo-cubillán, M CuquerellaAbstract:Haemonchosis, caused by the abomasal nematode Haemonchus contortus, is a common parasitic disease of sheep. Our previous results showed that a soluble fraction from adult stages of the nematode (p26/23) induced partial protection against challenge. Recombinant DNA technology was applied to obtain a synthetic protein (rHcp26/23). Immunological assays (ELISA, Western blotting, and immunolocalization), using sera from lambs immunized with p26/23, confirmed the identity of the recombinant protein and demonstrated that the synthetic protein is equivalent to the purified protein employed in the previous immunoprophylaxis studies. Vaccination of lambs with 300 μg of rHcp26/23 and Freund's adjuvant elicited a notable specific antibody response. Immunization did not induce any significant protection after challenge with 16000 infective larvae of H. contortus, and comparable values for parasite faecal egg output, packed cell volume, and abomasal parasite burdens were found in vaccinated and control animals
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immunization against ovine Haemonchosis with three low molecular weight somatic antigens of adult haemonchus contortus
Journal of Veterinary Medicine Series B-infectious Diseases and Veterinary Public Health, 2003Co-Authors: J M Alunda, Francisco Angulocubillan, M CuquerellaAbstract:Individual bands (15) from electroblotted soluble extracts of adult Haemonchus contortus were excised and three peptides of molecular weight ca. 56 (F4), 39 (F8) and 18.5 kDa (F14) used to vaccinate 4-4.5-months-old lambs against the nematode. Immunizing doses from each peptide were administered in 1 ml Freund complete adjuvant (first 50 microg injection) and 1 ml Freund incomplete adjuvant (second and third 50 microg injections) to six lambs. Two weeks after last immunization, animals were challenged with 300 L-3/kg live weight (LW). Lambs were slaughtered 34 days after challenge. Immunization induced a strong antibody response estimated by enzyme-linked immunosorbent assay, whereas no peripheral lymphoproliferative response was observed. Lambs in the F8-vaccinated group showed on average delayed pre-patent period, lower faecal egg counts and reduction of abomasal worm burdens, although the differences were not statistically significant.
Claudia Ribeiro Do Valle - One of the best experts on this subject based on the ideXlab platform.
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utilizacao do metodo famacha no diagnostico clinico individual de haemoncose em ovinos no sudoeste do estado de minas gerais
Revista Brasileira De Parasitologia Veterinaria, 2010Co-Authors: Diana Cuglovici Abrao, Silvana Abrao, Carlos Henrique Cabral Viana, Claudia Ribeiro Do ValleAbstract:The aim of this study was to evaluate the efficacy of Famacha method in individual clinical diagnosis of Haemonchosis in sheep from the south-west of Minas Gerais. Fifty crossbred Santa Ines ewes were evaluated during 5 months as for conjunctival mucous colour (Famacha method), Packed Cell Volume (PCV), Faecal Egg Counts (FEC), body score and clinic alterations. The score Famacha observed was from 1 to 3, the body score from 2 to 5, the PCV from 20 to 47%, and FEC from 0 to 7,750. The correlations between the parameters evaluated, except Famacha with body score, were highly significant (P < 0.0001). The main genus identified in the coprocultures was Haemonchus (87 - 100% of total larvae, ± 93.5%). We observed reduction of 87.33% in the use of anthelmintics on the property. It was concluded that the Famacha method, associated with other diagnostic methods, is a useful tool to detect hemonchosis in sheep.
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Utilização do método Famacha no diagnóstico clínico individual de haemoncose em ovinos no Sudoeste do Estado de Minas Gerais Utilization of the Famacha method in individual clinic diagnostic of Haemonchosis in sheep of south-west of Minas Gerais State
Colégio Brasileiro de Parasitologia Veterinaria, 2010Co-Authors: Diana Cuglovici Abrao, Silvana Abrao, Carlos Henrique Cabral Viana, Claudia Ribeiro Do ValleAbstract:O objetivo deste estudo foi observar a eficácia do método Famacha no diagnóstico clínico individual de haemoncose em ovinos provenientes do Sudoeste de Minas Gerais. Cinquenta ovelhas mestiças Santa Inês foram avaliadas durante 5 meses quanto à coloração da mucosa conjuntiva (método Famacha), volume globular (VG), ovos por grama de fezes (OPG), escore corporal e alterações clínicas. O escore Famacha observado variou de 1 a 3; o escore corporal de 2 a 5; o VG de 20 a 47%; e o OPG de 0 a 7.750. As correlações entre os parâmetros avaliados, exceto Famacha com escore corporal, foram altamente significativas (P < 0,0001). O principal gênero identificado nas coproculturas foi Haemonchus (87 a 100% do total de larvas, ± 93,5%). Constatou-se redução de 87,33% na utilização de anti-helmínticos na propriedade. Conclui-se que o método Famacha, associado a outros métodos de diagnóstico, é ferramenta útil na detecção da haemoncose em ovinos.The aim of this study was to evaluate the efficacy of Famacha method in individual clinical diagnosis of Haemonchosis in sheep from the south-west of Minas Gerais. Fifty crossbred Santa Inês ewes were evaluated during 5 months as for conjunctival mucous colour (Famacha method), Packed Cell Volume (PCV), Faecal Egg Counts (FEC), body score and clinic alterations. The score Famacha observed was from 1 to 3, the body score from 2 to 5, the PCV from 20 to 47%, and FEC from 0 to 7,750. The correlations between the parameters evaluated, except Famacha with body score, were highly significant (P < 0.0001). The main genus identified in the coprocultures was Haemonchus (87 - 100% of total larvae, ± 93.5%). We observed reduction of 87.33% in the use of anthelmintics on the property. It was concluded that the Famacha method, associated with other diagnostic methods, is a useful tool to detect hemonchosis in sheep
Bravo Olga - One of the best experts on this subject based on the ideXlab platform.
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Validación del método Famacha© como herramienta en el control de Haemonchosis en pequeños rumiantes
'University of Panama Faculty of Medicine', 2021Co-Authors: Pile Edwin, Higuera Germán, Torres Alicia, Pérez Alexander, Pérez Dimas, Bravo OlgaAbstract:From September to October 2012, a study was conducted to validate FAMACHA© method as a tool in controlling Haemonchosis in small ruminants. The evaluated variables between animals from Colón and Herrera provinces were hematology, stool and FAMACHA© index. The results (n=270, CI=95%, error=5.5%) allowed to verify the use of the method as a useful tool in identifying anemic animals, suggesting their use in the selective, safely and reliably treatment of sheep and goats with Haemonchosis.De septiembre a octubre de 2012 se realizó un estudio para la validación del método FAMACHA© como herramienta en el control de Haemonchosis en pequeños rumiantes. Las variables evaluadas entre animales procedentes de las provincias de Colón y Herrera fueron los índices de hematocrito, número de huevos por gramo de heces y Famacha. Los resultados (n=270, IC=95%, error=5.5%) permitieron comprobar el uso del método como herramienta útil en la identificación de animales anémicos, sugiriendo su uso en el tratamiento selectivo, seguro y confiable de pequeños rumiantes en el caso de Haemonchosis
