Presentation on theme: "What disease killed 300-500 million people worldwide but has since been eradicated from the human population? Smallpox 1157 BC; Egyptian pharaoh Ramses."— Presentation transcript:
What disease killed 300-500 million people worldwide but has since been eradicated from the human population? Smallpox 1157 BC; Egyptian pharaoh Ramses V mummy has smallpox lesions.
Progression: Rash Pus-filled blisters Disfiguration and/or blindness Death rate = 30% Man with smallpox; Public Health Images Library. Source: CDC
Queen Elizabeth 1 Had smallpox in 1562 Source: Google images
Take pus from a lesion and put into vein or scratch in arm of a healthy person. Amount of virus varied, and some would die. George Washington had his army “variolated” during America’s War of Independence
Physician who heard milkmaids say they never got smallpox if they had cowpox In 1796, put pus from cowpox into cut on boy; 8 weeks later exposed him to smallpox. Slow acceptance, then widely adopted Vacca = latin word for “cow”
Vaccine made with cowpox virus Causes body to produce antibodies that protect against smallpox Side effects: red spot, pustules, scabs, leaves a scar. Fever is common, swelling. Fatal complications are rare: 1 death per million vaccines
1967: WHO announces global smallpox eradication program. Still 15 million new cases a year then 1977: Last reported naturally occurring case in Somalia. Smallpox is the only disease totally eradicated in humans
Virus kept in labs in US, Russia & France Russian scientists claimed they could make smallpox in large amounts in “scatter bombs.” Later: Where did the Russian scientists go? May not know for days – until symptoms happen Today 50% of U.S. never vaccinated Routine vaccination discontinued in 1972 Boosters needed at 10 years After 9/11/01, 150 million vaccines ordered Controversial
Feb 2008: DoD switched to new “biodefense vaccine.” Grown in lab cell cultures (monkey kidney cells) instead of on cow skin. Similar to old vaccine but advanced production capabilities. Used only for those at “high risk”. CDC emergency- stockpiled ~200 million Goal: Develop a second generation smallpox vaccine
Ring around the rosy, A pocket full of posies, Ashes… Ashes, We all fall down! Written in London in 1665
Bubonic Plague Ring around the rosy = dark-ringed red spots in the skin from infected flea bites. Pocket full of posies = belief that disease carried by putrid-smell of the lesions made people carry posies close to their nose Ashes…Ashes = Bodies were cremated (not the norm in those days) All fall down = death 60% of London died
Great fire of London finally killed the rats The brown rat, house rat, sewer rat, Norway rat = carriers of Bubonic Plague
Excessive sneezing of plague sufferers led Pope Gregory VII to coin “God Bless You” as a holy response when someone sneezes. Plague (bacteria) infects both people & rodents. Fleas (vector) transmit to people. Infected people transmit by coughing, sneezing, close talking Came closest to wiping out the human race. 50 million people died from 1347-1352 (~50-60% of Europeans)
San Francisco 1907-1908 After the 1906 earthquake Homeless rats and homeless people Anti-rat campaign lasted 4 years 25 cents per rat
Plague does still exist in parts of the world WHO reports 1,000 – 3,000 cases per year Usually where infected rodents live close to humans Recent outbreaks: Russia, China, Kenya, Zaire, Bolivia Have there been any human cases in the U.S.?
WWII: Japanese army dropped plague- infected fleas over China. Both US and Soviet Union developed techniques to aerosolize the Plague bacteria. Pneumonic Plague = most severe threat Most deadly form – rapid symptoms and close to 100% fatality rate. Vaccine (3 doses) is for bubonic plague only With antibiotic treatment = 50% fatality rate Because of delayed treatment
Caused by Salmonella – typhi (bacteria) Mostly spread through water Also food and from other infected people 10% death rate in early 1900’s Clean water supply prevents typhoid; there is also a typhoid vaccine Carrier = person who has a disease-causing organism on their skin or in their body. Carriers may not be sick, but can spread disease if come in contact with others.
6 of 11 people in a house got typhoid fever in 1906 Bad water & food ruled out; Mary refused to be tested Mary tested against her will when 22 more people got typhoid Mary put into isolation, released after 3 years.