On This Day: Bubonic Plague Spreads Throughout San Francisco

San Francisco had been coping with the bubonic plague since 1900, but the May 1907 outbreak was the result of an increase in rat population caused by the earthquake of 1906, the San Francisco Department of Health says. The plague, which previously had been confined to Chinatown, spread throughout the city and finally drew enough attention to generate a solution: disposing of the rats.

The bubonic plague epidemic in San Francisco lasted from 1900 to 1909. It came to California in 1899 via a ship traveling from Hong Kong. Outbreaks began in 1900 in San Francisco’s Chinatown, where people were living in the kind of close quarters that helped the spread of disease. “The Chinese had a great fear that this public health ruse of this plague thing, with the plague diagnosis, was going to be used against them,” UCSF professor and doctor Guenter Risse told San Francisco's NBC affiliate, KRON 4. Chinatown was ultimately quarantined, and 22 people died.

Several unsuccessful attempts to curb the outbreak were made. According to PBS, “commissions and boards formed, fought with the governor, and were disbanded, underfunded, and reformed.” Meanwhile, scientists were busy proving that the plague was carried by pests and rodents. These theories were not widely accepted until 1908, but San Francisco began to solve its problem by controlling the rat population.

The Black Death first appeared in Italy in 1348. The Web site EyeWitness to History publishes an account by Italian writer Giovanni Boccaccio about what it was like in Florence when the plague began to take over the city. He describes the disease as spreading like fire from the sick to healthy and said that people died within three days of contracting it. No doctor could cure it.
 
In 2007, a monkey at the Denver Zoo died of the bubonic plague. Zookeepers suspected she caught the plague by eating a squirrel that had caught the plague when a neighboring rodent population was infected. The other monkeys were treated with antibiotics and were back in their cages for public viewing shortly. Steve Feldman, a spokesman for the Association of Zoos and Aquariums told The New York Times that “it shouldn’t be alarming to the public, either. Animals in zoos are kept appropriately separated from the visiting public and receive the highest level of veterinary care.”

The Centers for Disease Control explains the origins and transmission of the plague.