1929–1930 psittacosis pandemic

In Algiers, four deaths were attributed to the disease in the week ending 8 February 1930. The following week, three further cases were reported.[12]

Cases in Germany were reported, with some uncertainty, from July 1929, in Berlin, Hamburg, Liegnitz, Munich, Glauchau and Dôbeln. It resulted in the banning of the importation of parrots.[14] By the end of the pandemic in early 1930, Germany had the largest number of cases, with 215 affected, of which 45 died. Parrot-owners were found abandoning their birds at the Berlin zoo, and in response the zoo closed its gates.[2][15]

Of 35 parakeets involved in the German cases, 30 had no disease.[15]

Cases were reported in Birmingham, United Kingdom, in mid 1929. In December 1929, a ship's carpenter attended the London Hospital with a typhoid-like illness. He had previously purchased two parrots from Buenos Aires, which had died en route to London. By March 1930, 100 suspected cases were reported across the UK. One case was linked to a visit to a pub, where there was noted to be a sick parrot.[2][16][17]

Research into the cause was commenced by Samuel Bedson at the London Hospital.[2]

In the UK, the Parrots (Prohibition of Import) Regulations, 1930 was created following consideration by the permanent committee of the Office international d'hygiène publique.[18] It prohibited the trade of parrots unless for research.[19]

In early January 1930, an outbreak of "mysterious pneumonias" in the United States came to media attention when cases in three members of one family were traced to the previous Christmas importation of parrots from South America.[20][21] 10 days before Christmas, Simon Martin, secretary of the Chamber of Commerce in Annapolis, Maryland, bought a parrot in Baltimore for his wife, who subsequently, along with their daughter and son-in-law, became seriously ill.[22][23] Their new parrot's feathers had become dirty and ruffled by Christmas Eve, and on Christmas Day it died. The wife of the family physician made a link to a newspaper article about "parrot fever" in Buenos Aires. In consequence, Martin's physician sent a telegram to the United States Public Health Service (PHS) in Washington DC, requesting for advice on parrot fever. The story came to the attention of Surgeon General Hugh S. Cumming, who received similar messages from Baltimore, New York, Ohio and California. The task of solving the cause of parrot fever was signposted to George W. McCoy, the director of PHS's Hygienic Laboratory and a renowned bacteriologist who had discovered tularaemia, and his deputy, Charlie Armstrong, neither of whom had ever heard of parrot fever.[2]

On 8 January 1930, The Washington Post reported "parrot disease baffles experts" and headlines of "Parrot Fever Hits Trio at Annapolis".[2][11] On the same day, the outbreak made headlines in the Los Angeles Times with "two women and man in Annapolis believed to have 'parrot fever'".[11][24] On 11 January, the same paper reported "Parrot Disease Fatal to Seven",[2] and the Chicago Daily Tribune put on their front page "Baltimore woman dies".[11][24] By 15 January, 50 cases were reported nationwide.[11] The following day, the Baltimore Sun announced that "Woman's Case Brings Parrot Victims to 19". During this time, one of the first deaths was particularly alarming. The victim was a woman in Toledo, Ohio, who had been given three Cuban parrots by her husband.[2]

Cumming warned to stay away from imported parrots,[2] whilst sailors at sea were ordered by one U.S. Navy admiral to throw overboard their parrots. Some were encouraged by one health commissioner to kill their pet parrots, and some abandoned them on the streets.[11][24]

Reports soon began to follow from the eastern coast of the U. S., with Baltimore, New York City and Los Angeles, involving other birds such as shell parakeets (Australian budgerigars). The director of the Bureau of Communicable Diseases, Daniel S. Hatfield, ordered the confiscation of all birds at Baltimore pet stores.[2]

Six major pet dealers in the U.S. stood to make a loss of $5 million per year as a result of an executive order issued by President Herbert Hoover on 24 January prohibiting "the immediate importation of parrots into the United States, its possessions and dependencies from any foreign port", until research could find the cause and mode of transmission. This decision came following Armstrong's initial research, which showed that healthy parrots being infected by sick ones and that some could become asymptomatic carriers. The following day, Armstrong's assistant, Henry "Shorty" Anderson, became ill.[2][25]

Henry "Shorty" Anderson (right)

Two of the 16 people that developed the illness from exposure at the National Hygiene Laboratory died, including, on 8 February, Anderson.[4] The following day, bacteriologist William Royal Stokes died, only weeks after commencing research on the parrot dropping samples given to him by Armstrong. By this time, Armstrong was ill himself but survived. They had failed to isolate the causative infectious agent, and McCoy was subsequently forced to kill the birds and fumigate the Hygienic Laboratory.[2]

43 of the 74 foci in the U.S. were traced to contact with Amazon parrots. Links were traced to Japan, Caribbean, Germany, Central America and South America.[4] Between November 1929 and May 1930, the U.S. recorded 169 cases, of which 33 died.[4] New York was the centre of the East Coast bird trade. However, the principal ports of entry for Australian budgerigars was San Francisco and Los Angeles. Later, it was discovered that the main source was domestic lovebirds raised in hundreds of independent Californian aviaries by breeders who were supplementing their incomes following the recent Wall Street Crash. The winter of 1929 was also witnessing an influenza epidemic and there were fears of a recurrence of Spanish flu, which added to the depressive effects. In this context, peddlers travelled door-to-door with “lovebirds” for housewives and widows. As a result, most victims in the U.S. were women. The realisation and connections of the various outbreaks may not have become apparent had it not been for the press. Likewise, the "hysteria" and heightened public concern surrounding the pandemic may not have occurred had it not been for headlines such as “Killed By A Pet Parrot.”[2][4]

The establishment of the National Institutes of Health is directly linked to the outbreak that occurred in Maryland.[26] Its story was retold in Paul de Kruif's, Men Against Death (1933).[27]

• 
  Canary (Serinus canaria)
• 
  Budgerigar (Melopsittacus undulatus)
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  Peach-faced lovebird (Agapornis roseicollis)
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  Orange-winged amazon (Amazona amazonica)
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  African grey parrot (Psittacus erithacus)