An outbreak of bubonic plague in San Francisco in 1907 killed few people because the city immediately launched a campaign to exterminate the rats whose fleas transmitted the disease.
San Franciscos aastal 1907 puhkenud muhkkatk nõudis vaid mõne üksiku elu, sest linnas algatati otsekohe rottide hävitamise kampaania, sest nende kirbud olid haiguse edasikandjaks.