Molecular epidemiology of anaplasmosis in Indian dromedary camels

The present study aimed to investigate the molecular epidemiology, risk factors, and haemato-biochemical changes in anaplasmosis in Indian dromedary camels. Blood samples collected from 103 camels were analysed using blood smear examination and semi-nested PCR based on the 16s rRNA gene to diagnose anaplasmosis. The prevalence of anaplasmosis was estimated to be 42.72% (95% CI: 33.59-52.37) by PCR assay and 16.5% (95% CI: 10.47-24.95%) by blood smear examination. Phylogenetic analysis of six partial sequences of 16s rRNA gene obtained in the present study indicated the involvement of multiple Anaplasma species, including A. marginale and A. platys, showing genetic similarity with cattle strains. A novel genotype related to A. camelii/A. cinensis/A. platys group was also identified. Hemato-biochemical examination revealed mild anaemia, increased serum urea nitrogen and creatinine levels, and decreased total protein and albumin levels in Anaplasma-positive animals. The infections were largely subclinical in nature, except in one camel that revealed fever, inappetence, and pale mucous membrane and responded well to treatment with oxytetracycline. To our knowledge, this is the first molecular study on camel anaplasmosis in India, indicating a high prevalence of infection and involvement of multiple Anaplasma species with potential risk for interspecies transmission.