USA HISTORY

Detailed explanation-1: -When the Europeans arrived, carrying germs which thrived in dense, semi-urban populations, the indigenous people of the Americas were effectively doomed. They had never experienced smallpox, measles or flu before, and the viruses tore through the continent, killing an estimated 90% of Native Americans.

Detailed explanation-2: -The list of infectious diseases that spread from the Old World to the New is long; the major killers include smallpox, measles, whooping cough, chicken pox, bubonic plague, typhus, and malaria (Denevan, 1976, p.

Detailed explanation-3: -In the Old World, the most common form of smallpox killed perhaps 30 percent of its victims while blinding and disfiguring many others. But the effects were even worse in the Americas, which had no exposure to the virus prior to the arrival of Spanish and Portuguese conquistadors.

Detailed explanation-4: -Smallpox. The WHO smallpox eradication campaign was launched in its intensified form in 1967, and in four years had wiped out smallpox in Latin America.