Epidemiological and biochemical studies on bovine anaplamosis in dakahlia and demiatta governorates in Egypt
This study whose objective was to determine epidemiological, clinical and biochemical characteristics of bovine anaplasmosis was carried out into two phases. The first phase was carried out in November 2005 to October 2006 . The prevalence of bovine anaplasmosis was determined using thin blood film and IFT and the associated risk factors such as age, season and farm system were determined. In addition, evaluation CBC and oxidant-antioxidants markers in A. marginale infected cattle was also undertaken. Of the 3310 cattle examined during the first pahse 136 were suspected to have anaplasmosis.. Of this, 85.2% (116/136) and 89.7% (122/136) were positive for A. marginale by thin blood smear test and by IFT, respectively. The total prevalence were 3.5% and 3.68% on the basis of blood film and IFT respectively. In relation to season, the highest prevalence was recorded in summer 5.7 % and 5.9 % for stained blood film and IFT respectively. While animal aged between 1-3 years showed highest prevalence. The rural farms showed high prevalence in comparison with modern farms 11.5% and 0.45% respectively. There was significant decrease (p=0.05) in Hb, RBC and PCV in animals with anaplasmosis compared to healthy ones. Oxidant-antioxidants markers estimation revealed significant (p=0.05) elevation of oxidant markers and decreased levels of antioxidant markers in infected cattle. The second phase was carried out from November, 2006 to October, 2007 on 35 rural farms and 5 modern farms to estimate the Anaplasma marginale enzootic stability. Unstable situation of Anaplasma marginale in rural farms, and minimal situation disease in modern farms were recorded. The different Anaplasma marginale situation in the district needs more attentionin regard to translocation of the calves from modern farms to rural farms as well as during vaccination for other diseases especially when single
needles are used for vaccinating multiple animals.
Keyword: Anaplasma marginale, prevalence, enzootic situation, oxidative stress