how rare is Psittacosis in humans and parakeets?

what are symptoms and how can domesticated birds get it if they have stayed in the house and occasionally outside in the cage for fresh air?

Birds and humans: An entry from Thomson Gale’s Grzimek’s Animal Life Encyclopedia

Product Description

Gale proudly presents the completely revised and updated version of the acclaimed “Grzimek’s Animal Life Encyclopedia” set. Hailed by many as the best reference work on animals ever published, a legacy left to us by famed zoologist and animal lover Bernhard Grzimek, this set is renowned for its scientific reporting and coverage, and serves as a major point of reference for researchers, students, and those hoping to satisfy their curiosity about the animal kingdom. Information can be found on life cycles, predators, food systems, overall ecology and much more. Staying true to the original scientific pedigree, Gale enlisted prominent advisors and contributors from the international scientific community to incorporate recent developments in our knowledge of the animal world.