Toxic-oil syndrome: case reports associated with the ITH oil refinery in Sevilla.

Toxic-oil syndrome (TOS), a new disease that occurred in epidemic form in Spain in 1981, has been associated with the ingestion of unlabelled oil bought principally from travelling salesmen. Chemical analysis of oils taken from ill families has shown them to consist of varying proportions of different vegetable oils and animal fats, often showing chemical evidence of prior treatment with aniline. We investigated the unusual circumstances surrounding the reported occurrence of three TOS cases in two families in Sevilla, a city located far away (approximately 300 km) from the group of 14 provinces in central and northwestern Spain where 99% of the TOS cases occurred. Each case we investigated fitted the clinical picture of TOS and was not consistent with any other diagnosis. Illness apparently occurred as a result of ingestion of oil taken from the ITH oil refinery in Sevilla, a plant in which rapeseed and grapeseed oils were refined for the distributing firm through which oil bearing the causative agent of TOS is thought to have entered the market. These data provide further strong support for the hypothesis that food oil was the vehicle by which the aetiological agent of TOS was transmitted. Because ingestion of refined denatured rapeseed oil was most closely associated with the illness in time, the TOS agent was probably contained initially in this type of oil. The agent very probably entered later oil mixtures through such contaminated rapeseed oil.