Psittacosis is spread primarily from birds. While typically associated with parrot-like species, such as lovebirds (Agapornis roseicollis), many different types of birds can carry the bacteria. The infected birds may not show any signs of illness. People are typically exposed when particles of bird feces or urine are introduced to the air through blowing dust, landscaping activities, etc. Direct handling of infected birds can also be a source of infection.
Psittacosis usually causes a respiratory infection with symptoms of cough, fever, headache, and discomfort. Some cases may develop pneumonia. In very rare cases infections can spread to other organs such as the heart, kidneys, liver, and brain.
Not much evidence of spreading person to person. While psittacosis is not usually contagious, it is recommended that sick people cover their coughs and that others avoid contact with respiratory secretions.