Q fever (query fever) is a rare bacterial infection that can affect animals and humans. In animals, bacteria that cause Q fever are found most frequently in cattle, sheep, and goats. The bacteria are excreted in milk, urine, and feces of infected animals. During birthing the organisms are shed in high numbers within the placenta and birthing fluids. The organism is resistant to heat, drying, and many common disinfectants which enable the bacteria to survive for long periods in the environment. Infection of humans usually occurs by inhalation of dust or other particles contaminated with the bacteria. Other modes of transmission to humans are rare but include tick bites, ingestion of unpasteurized milk or dairy products, and human to human transmission. Humans are often very susceptible to the disease, and very few organisms may be required to cause infection.