Not until a universal, reliable test is available. It seems the Spanish study is probably not detecting enough of the prior infected and the Italian one probably had too many false positives. The true answer is probably somewhere in the middle.
The word Indian came to be used because Christopher Columbus repeatedly expressed the mistaken belief that he had reached the shores of South Asia. Convinced he was correct, Columbus fostered the use of the term Indios (originally, “person from the Indus valley”) to refer to the peoples of the so-called New World.