Anaplasma phagocytophilum in cattle parasitism in Benin: An emerging pathogen transmitted by ticks

Anaplasma phagocytophilum, a bacterium transmitted by ticks, is responsible for granulocytic anaplasmosis, an emerging zoonosis that has never been reported nor identified previously in Benin and in the West African sub-region. This study is designed not only to investigate the prevalence of the disease and evaluate mortalities recorded at Kpinnou farm after importing Girolando cattle from Brazil in 2014 but also to assess the prevalence of the emerging disease in Benin in the year 2014 period. A total number of 1427 ticks were collected, including 5 ml of blood from each one hundred cattle. Microscopic diagnosis reveals the presence of Rhipicephalus (Boophilus) spp., Rhipicephalus microplus, Amblyomma variegatum, Rhipicephalus spp and Hyalomma spp. Blood analysis results reveal the occurrence of 55% positive cases for A. phagocytophilum. Considering the effeiciency of the methods, 100% of A. phagocytophilum reported as positive by microscopy appear to be also positive with molecular analysis. PCR has greater sensitivity and specificity even with microscopy showing appreciable specificity. This study concludes that Anaplasma phagocytophilum is the primary suspect responsible for the massive deaths observed in cattle in the study area.