 The terrible plagues that swept the peninsula were recorded in Yucatec Maya written histories, which combined with those of neighbouring Maya peoples in the Guatemalan Highlands, suggest that smallpox was rapidly transmitted throughout the Maya area the same year that it arrived in central Mexico with the forces under the command of Pánfilo Narváez.Old World diseases are often mentioned only briefly in indigenous accounts, making it difficult to identify the exact culprit.Among the most deadly were the aforementioned smallpox, influenza, measles and a number of pulmonary diseases, including tuberculosis; the latter disease was attributed to the arrival of the Spanish by the Maya inhabitants of Yucatán.