First Molecular Evidence of Coxiella burnetii in Ticks Collected from Dromedary Camels in Punjab, Pakistan

This study surveyed the existence of the Coxiella burnetii in ticks removed from camels in three different regions of the Punjab, Pakistan. A total of 325 ixodid ticks were analyzed for the occurrence of C. burnetii DNA by real-time polymerase chain reaction. Before analyses, all ticks were pooled into 30, 20 and 15 pools from Southern, Northern and Central Punjab, correspondingly. Each pool was comprised of five engorged or semi-engorged ticks according to species. Pooled based prevalence in Southern Punjab was eighteen from 30 pools (60%), leading to maximum-likelihood of true prevalence of 0.56% (95% CI 0.23-1.31), while pooled prevalence in Northern Punjab was eight from 20 pools (40%), leading to maximumlikelihood of the true prevalence of 0.44% (95% CI 0.31-0.89) and none of the pooled samples from Central Punjab were found positive for C. burnetii. During classification of tick pools based on species, infection was diagnosed in 75% (09/12) of H. dromedary, 42.8% (03/07) of H. anatolicum, 50% (01/02) of H. scupense, 60% (03/05) of R. microplus, and 50% (02/04) of R. annulatus in Southern Punjab. In comparison, infection was detected in 37.5% (03/08) of H. dromedary, 23% (01/04) of H. anatolicum, 0% of H. scupense, 66.7% (02/03) of R. microplus and 66.7% (02/03) of R. annulatus in Northern region. The detection of C. burnetii implies important role of ticks in the dissemination of this bacterium in Punjab, Pakistan and reveals that ticks have a major contribution to the epidemiology of coxiellosis in this ecological system. These judgments warrant further molecular investigations for better perception about C. burnetii epidemiology and its contributions to humans and animal disease in Pakistan.