Since the outbreak of the epidemic there was a great confusion about its causes. The early pulmonary symptoms made suspect of a respiratory infection. Even those researchers who thought of a non infectious etiology believed that a possible exposure via respiratory tract could be the cause. This error in the initial hypothesis originated delays in the discovery of the real cause of the disease and lateness in public health action to prevent that more people were affected.

Tabuenca JM. Discovery of toxic oil as the cause of the epidemic. In: World Health Organization, editor. Toxic Oil Syndrome: mass food poisoning in Spain. 1 ed. Copenhagen: World Health Organization, Regional Office for Europe; 1984. p 39-46.