Q fever, also called query fever, is a bacterial infection caused by the bacteria Coxiella burnetii. The bacteria are most commonly found in cattle, sheep, and goats around the world. Humans typically get Q fever when they breathe in dust that was contaminated by infected animals. Farmers, veterinarians, and people who work with these animals in labs are at the highest risk of being infected. The highest amounts of bacteria are found in the "birth products" (placenta, amniotic fluid) of infected animals. The disease may cause mild symptoms similar to the flu. However, many people have no symptoms at all. Mild forms of the disease may clear up in a few weeks without any treatment.
In rare cases, a more serious form of disease develops if the infection is chronic, which means it persists for six months (and there are some case reports indicating that it may persist for more than six months). A more serious form also can develop if the infection is recurrent, which means it comes back. People with heart valve problems or weak immune systems are at the highest risk of developing these types of Q fever. Chronic Q fever is very serious because it can damage a person’s vital organs, including the:
heart
liver
brain
lungs
More severe or chronic forms of Q fever can be treated with antibiotics. Those at risk for Q fever can prevent the disease by disinfecting contaminated areas and washing their hands thoroughly.