Short answers, pulled from the story.
The Harvard Medical Ad Hoc Committee on Brain Death issued its landmark report in 1968. This report shifted how doctors determine when a person has died by proposing irreversible loss of all brain function as the new legal definition.
Cardiovascular disease remains the leading specific cause of human mortality worldwide. Infectious diseases dominate death rates in developing countries where sanitation and modern medicine are scarce.
Most U.S. states adopted the Uniform Determination Of Death Act following a 1980 conclusion by the President's Commission for the Study of Ethical Problems in Medicine. This law requires irreversible cessation of all brain function before declaring someone legally dead.
Tuberculosis killed 1.8 million people in 2015 alone according to global health records. Malaria caused about 2.7 million deaths annually around 2004.
Physician J.C. Ouseley claimed in 1895 that as many as 2,700 people might have been buried alive each year though other estimates suggest closer to 800 cases annually. Misdiagnosis remains a persistent risk as evidenced by historical anecdotes of premature burial.