{'fraction_non_alphanumeric': 0.025818639798488665, 'fraction_numerical': 0.007241813602015114, 'mean_word_length': 4.894248608534323, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Birds of a Feather—Do They Flock Together?

It is all the vogue to draw attention to communicable diseases that have been newly recognized (“emerging” infections), as well as those that now are resurgent after a period of decline (“reemerging” infections). Try as I might, however, I cannot place psittacosis into either category. The characteristic pneumonia of psittacosis initially was defined back in 1879 by Jacob Ritter, a Swiss physician who noted a cluster of seven illnesses that occurred among the members of his brother’s household.1 Ritter’s meticulous observations delineated the clinical manifestations of the disease (including splenomegaly, a clinical “pearl”), the often fatal outcome (three of the seven patients died, including his brother), and the gross pathological findings. Ritter reconstructed the family’s comings and goings during the weeks before the onset of these illnesses and deduced that the disease was an infection and that it emanated from a point source. He deduced further that the source was located within a single room of his brother’s house: his study, the only room to which all the cases had been exposed. Because the study had, of course, always been part of the house, Ritter reasoned that the source must have been something that had been newly introduced into the study. His brother was a bird fancier, and, sure enough, just 3 weeks before the outbreak started, four new birds had been acquired and had been caged in the study. Another bird in the same shipment died shortly after arrival. Although Ritter’s sleuthing was right on the mark, he reported his suspicion that the birds were the source of this infectious illness, but refrained from drawing a firm conclusion. It was only after several other outbreaks occurred in Europe that the disease was given its name, derived from the Greek word (psittakos) for parrot, the bird that often was implicated as the source of infection. Then, as now, the illness was regarded as a rather rare and somewhat exotic sort of pneumonia. Psittacosis had its coming-out party in 1929, dramatically emerging on the international scene because of two factors. The first, as with many infectious diseases, had to do with lifestyle. During the good economic times of the 1920s, the hobby of keeping companion birds flourished, with the colorful birds of the tropics being especially favored. The majority of such pet birds were imported from South America. The second factor was an outbreak of psittacosis among bird flocks in Argentina that occurred just before the local breeders held a major auction of pet birds for wholesale distributors. The auction was attended by an international cadre of dealers, and many infected birds were shipped around the world. Over the next 2 years, outbreaks of psittacosis followed the introduction of these birds in the countries of Europe and the Middle East, as well as in the United States and Canada. Case totals could only be estimated, but numbers over 1,000 have been suggested; the mortality rate was thought to be on the order of 15% to 20%. Psittacosis certainly had emerged. In reaction to this global pandemic, the public health authorities