PREVALENCE AND DETERMINANTS OF BOVINE ANAPLASMOSIS IN SYLHET DISTRICT OF BANGLADESH

Abstract

Bovine anaplasmosis is endemic and occurs in cattle of several areas of Bangladesh including Sylhet. However, epidemiological parameters of this disease have not been explored extensively. The aim of this study was to estimate the prevalence and to identify the determinants of bovine anaplasmosis in cattle of Sylhet district by microscopic examination of Giemsa stained thin blood smears. Blood samples were collected from randomly selected 409 cattle of 64 cattle farms from 12 upazilas of Sylhet district during an eight-month period starting from October, 2014 through May, 2015. Animal and farm level information were collected from farmer’s record books and by interviewing farm owners or managers. Prevalences were calculated as a proportion of infected cattle/farms in total number of cattle/farms tested. Multivariable logistic regression was used to identify the determinants of bovine anaplasmosis. Overall animal level prevalence was 22.74%. The highest prevalence was in Jaintapur (50%) and the lowest in Golapganj (3.70%) upazila. Two species of Anaplasma namely Anaplasma marginale and Anaplasma centrale were identified in the study area. Anaplasma marginale was the most prevalent (12.71%) species causing infection in cattle followed by A. centrale (6.60%) and Mixed (3.42%), respectively. Farm level prevalence was 74.67%. Odd of overall bovine anaplasmosis was higher in local indigenous cattle than crossbred (Odds Ratio (OR) =1.98). Cattle from nonintensive had higher odd of being infected with Anaplasma marginale than intensively raised cattle (OR=1.64). Housing system was also a determinant for overall farm level anaplasmosis. The results of this study indicates that exposure of cattle to Anaplasma organism is common in Sylhet and findings of this study can be used for planning adoptive surveillance and control measures for bovine anaplasmosis. However, there is still a need for further investigations using advanced serological and molecular techniques to explore other epidemiological indices like host and vector range, spread, spatial and temporal trends etc.