Why would 70% of a state's cases of a rare bacterial disease have occured in one rural county?Residents in Churchill County, Nevada, are asking just that of state health officials. There were eight cases of Q fever reported in 2007 across Nevada, six of them in Churchill County. Two neighbors here who tested postitive with Q fever died last year. In 2006, all six cases of the disease in Nevada turned up in this same county, which is also "home to a childhood leukemia cluster." People who work around cattle, sheep, and goats are considered at risk for Q fever — usually caused by inhalation of coxiella burnetii bacterial spores (pictured above) — but neither of the men who died worked with livestock. They do both live in a subdivision that had been agricultural land 15 years ago.According to the Centers for Disease Control, there's no reason for alarm. CDC officials say that while the men who died tested positive for the bacteria, Q fever was not the cause of either's death. But Dr. Phil Larussa, a veterinarian with the agriculture department, confessed, "At this stage, we don't have any inkling where the disease is coming from."