There are considerable differences regarding the estimates of pre-Columbian population in America, but everybody agrees that a dramatic reduction occurred after the discovery of the New World. Smallpox has usually been blamed for much of this reduction. Yet historians agree that this disease was not introduced into the Isle of Santo Domingo until 1518. By then, the Indians of the Antilles had practically disappeared and the importation of an African labor force was underway to replace them.
No documented explanation has been offered for the causes of this earliest demographic disaster. The basic clinical signs, however, of the first American epidemic in contemporary descriptions, along with the concordance of the accounts, strongly suggest one conclusion. The epidemic that broke out in 1493 at the Isle of Santo Domingo and was responsible for the disappearance of the American Indians in the Antilles during the first quarter of a century after the discovery was swine influenza.