Clark NJ, et al. - Researchers conducted a systematic literature search to assess the strength of evidence for the role of distance from infected livestock facilities in human Q fever community outbreaks around the globe. In addition, they examined available evidence to evaluate the epidemiological factors and on-farm biosecurity measures that influence the likelihood of exposure of human communities to C. burnetii. They noted that Q fever environmental gradients were influenced by urbanization level, ruminant species, stocking density and wind speed. As per evidence gained, residential exclusion zones around holdings may be inadequate to contain this zoonotic disease, and should be species-specific.