People usually contract Q fever when they breathe in the Q fever microbe. It is very infectious. As few as ten Q fever microbes can start an infection. People can also get Q fever by drinking infected milk, but most infections are spread through the air. Person to person transmission occurs rarely, if ever.
People can have Q fever without knowing it or mistake it for mild flu.
Often, it is impossible to tell without laboratory tests. Sometimes, Q fever strikes as a sudden illness, affecting a large number of people in the same workplace. Some patients develop a slight, dry cough because of a lung inflammation known as pneumonitis. Most symptoms disappear after 7-10 days. However, afflicted people can feel generally ill with loss of appetite for several weeks.