Final answer:
The last case of smallpox in the wild was reported in 1977, and the disease was declared eradicated in 1980 due to a successful vaccination campaign by the WHO.
Step-by-step explanation:
The last known case of smallpox (in the wild) occurred in 1977. Smallpox, a contagious disease caused by the variola viruses, has a long history dating back to its believed origin in Northeast Africa around 30,000 AC. Methods to prevent and treat smallpox, such as variolation, originated in the Far East before eventually spreading to Europe and Africa. However, the disease remained rampant until an intense vaccination campaign led by the World Health Organization (WHO) drastically reduced smallpox cases through the 20th century.
Interestingly, the eradication of this disease, declared in 1980, was achievable because humans are the only known carriers of the virus, eliminating the natural reservoir once the human population became immune through vaccination. Despite eradication from the general population, smallpox stockpiles still exist in the United States and Russia for research and in case of re-emergence from unforeseen sources, such as preserved human remains. Ethical discussions continue as to whether these stockpiles should remain.