Microscopic alterations in Fasciola hepatica from sheep treated with albendazole / Alterações microscópicas em Fasciola hepatica de ovelhas tratadas com albendazol

Abstract Currently, albendazole is one of the most commonly used drugs because of its affordability. The objective was to evaluate the histopathology of Fasciola hepatica specimens. For this, the efficacy test was performed on sheep treated with albendazole at the dose recommended for F. hepatica, in which the helminths recovered at necropsy were counted and separated for histology. Spermatogenic cells from parasites recovered from treated and control sheep were examined by microscopy. The fecal egg-count reduction test revealed 97.06% efficacy of albendazole in the treatment of F. hepatica. Changes in testicular tubule cells started 48 hours after treatment and became evident within 72 hours, at which point it became difficult to identify cell types. Primary and secondary spermatogonia became increasingly rare and intercellular vacuolization was more evident. Signs of apoptosis, with pycnotic nuclei and evidence of keriorrexia were observed at all times. Cell debris was identified 96 hours after treatment. The results indicated that parasitic spermatogenesis was severely affected by albendazole and demonstrated the importance of the use of histopathology for the diagnosis of therapeutic efficacy in field strains.

Resumo Na atualidade, o albendazol é uma das drogas mais usadas devido à sua acessibilidade econômica. O objetivo foi avaliar a histopatologia dos espécimes de Fasciola hepatica. Para isso, foi realizado o teste de eficácia em ovinos tratados com albendazol na dose recomendada para Fasciola hepatica, no qual os helmintos recuperados em necropsia foram contabilizados e separados para histologia. As células espermatogênicas de parasitas recuperados de ovinos tratados e controle foram examinadas por microscopia. O teste de redução de ovos por grama de fezes revelou 97,06% de eficácia do albendazol no tratamento de F. hepatica. As alterações nas células dos túbulos testiculares iniciaram-se 48 horas após o tratamento e tornaram-se evidentes em 72 horas, altura em que tornou-se difícil identificar os tipos de células. As espermatogônias primárias e secundárias tornaram-se cada vez mais raras e a vacuolização intercelular foi mais evidente. Sinais de apoptose, com núcleos picnóticos e evidência de cariorrexia foram observados em todos os momentos. Os detritos celulares foram identificados 96 horas após o tratamento. Os resultados indicaram que a espermatogênese parasitária foi severamente afetada pelo albendazol e demonstrou a importância do uso da histopatologia para o diagnóstico de eficácia terapêutica em cepas de campo.

Microscopic alterations in Fasciola hepatica from sheep treated with albendazole.

Currently, albendazole is one of the most commonly used drugs because of its affordability. The objective was to evaluate the histopathology of Fasciola hepatica specimens. For this, the efficacy test was performed on sheep treated with albendazole at the dose recommended for F. hepatica, in which the helminths recovered at necropsy were counted and separated for histology. Spermatogenic cells from parasites recovered from treated and control sheep were examined by microscopy. The fecal egg-count reduction test revealed 97.06% efficacy of albendazole in the treatment of F. hepatica. Changes in testicular tubule cells started 48 hours after treatment and became evident within 72 hours, at which point it became difficult to identify cell types. Primary and secondary spermatogonia became increasingly rare and intercellular vacuolization was more evident. Signs of apoptosis, with pycnotic nuclei and evidence of keriorrexia were observed at all times. Cell debris was identified 96 hours after treatment. The results indicated that parasitic spermatogenesis was severely affected by albendazole and demonstrated the importance of the use of histopathology for the diagnosis of therapeutic efficacy in field strains.

Prevalence of liver condemnation due to bovine fasciolosis in Southern Espírito Santo: temporal distribution and economic losses.

The present study was conducted to evaluate the economic losses and temporal distribution of the prevalence of liver condemnation due to bovine fasciolosis. The abattoir in Atílio Vivácqua, in the South of the State of Espírito Santo, which is under state inspection by the veterinary service of the Livestock and Forest Protection Institute of Espírito Santo, was used as the data source. The prevalence of liver condemnation due to fasciolosis over the period 2006-2009 was calculated. The χ(2) test, simple linear regression analysis and χ(2) for trend were used, with a significance level of p ≤ 0.05. Over the period analyzed, 110,956 cattle were slaughtered and the prevalence of liver condemnation due to Fasciola hepatica was 15.24% in 2006, 23.93% in 2007, 28.57% in 2008 and 28.24% in 2009. The historical trend of liver condemnation is an increasing trend, thus indicating that this parasitism has become established in the herd as a problem in this region, with prevalence similar to that of traditionally endemic regions. Condemnations occurred throughout the year, with the highest prevalence in April and May and with significant differences between the dry and wet seasons. The economic losses from liver condemnation can be considered high.

Prevalence of liver condemnation due to bovine fasciolosis in Southern Espírito Santo: temporal distribution and economic losses / Prevalência de condenação de fígados bovinos por fasciolose no Sul do Espírito Santo: distribuição temporal e perdas econômicas

The present study was conducted to evaluate the economic losses and temporal distribution of the prevalence of liver condemnation due to bovine fasciolosis. The abattoir in Atílio Vivácqua, in the South of the State of Espírito Santo, which is under state inspection by the veterinary service of the Livestock and Forest Protection Institute of Espírito Santo, was used as the data source. The prevalence of liver condemnation due to fasciolosis over the period 2006-2009 was calculated. The χ2 test, simple linear regression analysis and χ2 for trend were used, with a significance level of p < 0.05. Over the period analyzed, 110,956 cattle were slaughtered and the prevalence of liver condemnation due to Fasciola hepatica was 15.24 percent in 2006, 23.93 percent in 2007, 28.57 percent in 2008 and 28.24 percent in 2009. The historical trend of liver condemnation is an increasing trend, thus indicating that this parasitism has become established in the herd as a problem in this region, with prevalence similar to that of traditionally endemic regions. Condemnations occurred throughout the year, with the highest prevalence in April and May and with significant differences between the dry and wet seasons. The economic losses from liver condemnation can be considered high.

O presente trabalho foi realizado com o objetivo de avaliar as perdas econômicas e a distribuição temporal da prevalência de condenação de fígados bovinos devido a fasciolose. O matadouro frigorífico de Atílio Vivácqua, no sul do Estado do Espírito Santo, com inspeção estadual, realizada por médico veterinário vinculado ao Instituto de Defesa Agropecuária e Florestal do Espírito Santo, foi utilizado como fonte de dados. A prevalência de condenação de fígados por fasciolose no período de 2006-2009 foi calculada. O teste do χ2, a análise de regressão linear simples e o χ2 para tendência foram utilizados, considerando-se o nível de significância p < 0,05. No período analisado foram abatidos 110.956 bovinos, observando-se prevalências de condenação de fígados por Fasciola hepatica, de 15,24 por cento em 2006, 23,93 por cento em 2007, 28,57 por cento em 2008 e de 28,24 por cento em 2009. A tendência histórica da condenação de fígados é crescente, indicando que este parasitismo estabeleceu-se no rebanho como um problema na região com prevalência similar a de regiões tradicionalmente endêmicas. As condenações ocorreram o ano todo com maior prevalência nos meses de abril e maio e com diferenças significativas entre os períodos seco e chuvoso. As perdas econômicas devido a condenação de fígados podem ser consideradas altas.