page_title: 1929–1930 psittacosis pandemic
section_title: Origin and global spread
hierarchical_section_title: 1929–1930 psittacosis pandemic / Origin and global spread
caption_attribution_description: English: Tags: interior, bird cage, parrot
context_page_description: The 1929–1930 psittacosis pandemic, also known as the psittacosis outbreak of 1929–1930 and the great parrot fever pandemic, was a series of simultaneous outbreaks of psittacosis which, accelerated by the breeding and transportation of birds in crowded containers for the purpose of trade, was initially seen to have its origin in parrots from South America. It was shortly found to have spread from several species of birds from several countries worldwide to humans between mid 1929 and early 1930. Diagnosed by its clinical features and link to birds, it affected around 750 to 800 people globally, with a mortality of 15%. Its mode of transmission to humans by mouth-to-beak contact or inhaling dried bird secretions and droppings was not known at the time. The cause, Chlamydia psittaci, which usually remains dormant in birds until activated by stress of capture and confinement, was discovered after the pandemic.
  Cases were reported in mid 1929, in Birmingham, United Kingdom, and linked to parrots from Buenos Aires, Argentina, where an ongoing outbreak of the disease had led to cautioning bird owners to declare their sick parrots.
context_section_description: There were multiple origins, involving several countries and several species of birds. Affected people typically experienced headache, poor sleep, fatigue and a cough trailing several days of fever. Some subsequently became delirious and semi-conscious, after which some died, and others recovered with a prolonged convalescent period.
  Initial outbreaks were linked to exotic birds from South America. The source of the Córdoba outbreak was traced to an import of 5,000 parrots from Brazil. The birds had been confined in unsanitary and crowded containers. Although the Argentine parrot trade was stopped, a number of birds were sold on to visitors to its seaports, and psittacosis, also known as parrot fever, was transmitted to several countries. Its mode of transmission to humans by mouth-to-beak contact or inhaling dried bird secretions and droppings was not known at the time. Germany, the United Kingdom and the United States were the most severely affected with more than 100 cases each. Implicated birds included green Amazon parrots, canaries, lovebirds and shell parakeets.
  By early 1930, the disease was reported in humans in several countries around the world, accelerated by the popular hobby of domestic bird-keeping at the time. Many cases and clusters had links with sick parrots. Around 750 to 800 people were affected. The average mortality was 15%, with a total of more than 100 deaths.
  The majority of cases in the U.S. were found in 1931 to be linked to endemic psittacosis in California, associated with the increasingly popular trade of breeding lovebirds for sale chiefly to housewives and widows.
caption: Caged budgerigars, 1933
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