What caused sudden illness in this otherwise healthy stockman?

Michael, a 30-year-old Australian-born stockman from a rural area presents with a three-week history of lethargy, 5kg weight loss, fatigue and coryzal symptoms

In addition, over the previous week, he had developed diplopia, a diffuse headache and a cough productive of white sputum. There was no rash or arthralgia.

Michael's work involves butchering cattle. He had no prior Q fever vaccination. He was a non-smoker, heterosexual, and had no alcohol or drug use history. There was no significant past medical or family history and he was not on any regular