Coxiella burnetii in bulk tank milk and antibodies in farm workers at Montería, Colombia¤

Background: Q fever is a zoonotic disease caused by Coxiella burnetii. In Colombia it is not a notifiable disease in humans and is most likely under diagnosed. There are no studies about its prevalence in important reservoir species, such as cattle. Objective: the aim of this study was to investigate the frequency of C . burnetii infection in cattle farms and determine the frequency of antibodies in farm workers at risk in rural areas of Montería, Córdoba (Colombia). Methods: eleven cattle farms were randomly chosen to investigate the infection by C . burnetii . Bulk tank milk samples of each farm were analyzed by conventional PCR for DNA detection of transposase gene IS1111 of C . burnetii. Serum samples from 61 apparently healthy people living in eight farms were analyzed by indirect inmunofluorescence against phase II IgG antibodies to C . burnetii . Results: we report the presence of C . burnetii DNA in 45% of bulk tank milk samples from cattle farms and a 61% frequency of antibodies (IgG phase II ≥1/64) in farm workers at risk. Conclusion: our results demonstrate the circulation of this bacterium in the studied farms in Montería, Colombia, showing that at-risk farm workers have a high antibody frequency.