Infected humans develop a flu-like illness which can be mild or severe in different individuals. Many humans have mild infections and recover without ever realizing that they have had Q Fever. A substantial portion of rural workers and those that work with ruminants have already had the disease, developed antibody, and are immune to further infection. Disease is most likely to be seen in urban workers who are working with ruminants for the first time. While most human cases are mild and flu-like, the disease can be a serious one.
Clinical signs begin from two weeks to one month after exposure.
Signs include fever, sweating, muscular aches and pains, and headache. In rare cases the organism can invade the heart and cause serious injury. Q fever is easily treated with appropriate antibiotics, so it s very important that a correct diagnosis be made if the illness might be Q fever. Human infection most commonly results from exposure to the amniotic fluid of infected ruminants, especially sheep. The organism spreads by aerosols, so direct contact with the fluid is not necessary - you only need to be in the same air space with the infectious material.