Episode Summary
Executive Summary: This episode of "This Podcast Will Kill You" examines plague in modern times: its biology, persistence as an endemic disease, the 2017 Madagascar outbreak, U.S. cases in the 20th century, and its potential as a bioterrorism agent. The hosts argue plague remains dangerous but is usually containable with surveillance, rapid diagnosis, antibiotics, and public health response.
Main Topics: Plague biology refresher: The hosts review Yersinia pestis transmission routes and the three clinical forms: bubonic, pneumonic, and septicemic plague, emphasizing differences in spread and fatality. The third plague pandemic and medical advances: They trace the late-19th/early-20th century third pandemic, when plague spread globally and researchers identified fleas, rats, and the causative bacterium, though early vaccines and treatments were weak. Plague in the United States: The episode explains how plague moved from port cities into wild rodent reservoirs in the western U.S., causing incidental human infections from animals and pets rather than sustained urban outbreaks. Madagascar outbreak of 2017: A detailed case study covers the outbreak’s origin, rapid spread, contact tracing, prophylaxis, and WHO response, showing how pneumonic plague can still produce major epidemics. Bioterrorism and historical misuse: The hosts discuss plague as a weapon in history and war, including alleged or documented attempts to use infected bodies, fleas, and bombs, and why plague remains a concern for biosecurity. Public health control and global risk: The episode concludes that plague is still endemic in multiple countries, but strong surveillance, sanitation, and rapid antibiotic treatment can keep it contained and reduce risk to listeners.
Key Arguments: Plague is not a purely medieval disease; it continues to cause outbreaks and deaths in the modern world, especially where it is endemic. The route of infection determines the disease form and severity: flea-borne bubonic plague is dangerous, pneumonic plague is far more lethal, and septicemic plague is also severe. Modern antibiotics and a functional vaccine exist, but access, logistics, diagnosis delays, and limited vaccine durability reduce their real-world effectiveness. The 2017 Madagascar outbreak showed that rapid epidemiologic investigation, contact tracing, and prophylactic antibiotics can substantially limit spread. Plague’s bioterrorism potential is real because Yersinia pestis is widely available and can be aerosolized, but its low R0 makes it less efficient than some other agents. In the U.S., plague is now mostly an animal-associated, sporadic disease rather than a major urban epidemic, though human cases still occur. Public health infrastructure, sanitation, and surveillance are the most important tools for reducing plague burden globally.
Data Points: Third pandemic deaths in China and India: more than 12 million - Deaths over one year at the start of the third pandemic (1855) in China and India alone Bubonic plague mortality: 30% to 60% untreated - Approximate mortality rate for bubonic plague if not treated Pneumonic plague mortality: up to 100% untreated - Approximate mortality rate for pneumonic plague if not treated Early vaccines/antibiotics effectiveness: 20% to 30% reduction in death chance - Late-1800s preventive/treatment measures were only modestly effective U.S. plague cases since early 1900s: over 1,000 - Total reported plague cases in the United States since the early 20th century U.S. cases since 1965: over 460 - Reported plague cases in the U.S. since 1965 U.S. plague case fatality since 1965: 16% - Mortality among reported U.S. cases since 1965 South Vietnam reported cases (1965-1970): over 25,000 - Officially reported bubonic plague cases during the Vietnam War era outbreak Estimated South Vietnam total cases: 100,000 to 250,000 - Likely true burden of the Vietnam outbreak based on underreporting Madagascar outbreak cases by Nov. 15, 2017: 2,119 - Combined confirmed, probable, and suspected plague cases Madagascar outbreak deaths by Nov. 15, 2017: 171 - Deaths reported in the 2017 Madagascar outbreak Madagascar outbreak case fatality rate: 8% - Overall case fatality rate during the outbreak Madagascar contacts traced: over 7,000 - Contacts identified during outbreak response Madagascar follow-up completion: 95% - Contacts who completed seven-day monitoring Madagascar initial case contacts: 31 ill, 4 deaths - People who became ill after contact with the first reported case Seychelles travel-associated investigation contacts: 320 - Contacts monitored after a suspected pneumonic plague case traveled from Madagascar to Seychelles Seychelles flight passengers traced: 41 - Passengers on the infected traveler’s flight from Madagascar Worldwide plague cases 2010-2015: over 3,000 - Global reported plague cases across those years Worldwide plague deaths 2010-2015: 584 - Global reported plague deaths across those years Pneumonic plague R0: about 1.3 - Estimated basic reproductive number for pneumonic plague Smallpox R0: about 6.5 - Comparison used to show plague is less transmissible than smallpox Measles R0: 13 - Comparison used to show measles is much more transmissible than plague
Pivotal Quotes: "Plague is endemic to Madagascar and plague season extends until April." — Erin Welsh: Discussing why the 2017 outbreak required continued surveillance beyond the initial surge "The bad one." — Erin Allmann Updyke: Referring to pneumonic plague during the Madagascar outbreak discussion "Thanks for now." — Erin Welsh and Erin Allmann Updyke: A joking acknowledgment that antibiotics currently remain effective against plague
Implications: Listeners should understand that plague remains a real but manageable disease. The main defense is early recognition, surveillance, sanitation, and rapid antibiotic treatment; without those, endemic regions and outbreak settings remain vulnerable.