Impact of rare diseases in oral health.

BACKGROUND: Rare diseases (RD) are those that present a lower prevalence than 5 cases per 10.000 population. The main objective of this review was to study the effect on oral health in rare diseases, while the secondary objective of the study is theme upgrade. MATERIAL AND METHODS: Comparative observational case-control studies were analysed and a systematic review was conducted in PubMed. Each rare disease listed on the statistical data record of the Health Portal of the Ministry of Equality, Health and Social Policies Board of Andalusia was associated with "oral health". The variables studied included dental, oral mucosa and occlusion alterations, oral pathologies (caries, periodontal disease) and other alterations (mouth breathing, parafunctional habits, etc). A bias analysis of the variable caries was conducted. RESULTS: Six RD were selected through our inclusion and exclusion criteria (hypogammaglobulinemia, Rett syndrome, Marfan syndrome, Prader-Willi syndrome, cystic fibrosis and Cri du chat syndrome) in a total of 8 publications, of which four trials were classified as high risk of bias and one of them as medium risk. There were not trials with low risk of bias. CONCLUSIONS: The main statistically significant differences found by Syndrome compared to a control group were in Hypogammaglobulinemia with a greater tendency to enamel hypoplasia and dry mouth. The Rett syndrome had, as well, a greater tendency to an anterior open bite, ogival palate, bruxism, mouth breathing and tongue thrusting. Prader-Willi syndrome had a tendency of dental erosion, and Cri du chat syndrome showed a higher association to Tannerella forsythia.

Childhood vasculitis hospitalizations in Spain, 1997-2011.

The aim of this study is to describe the childhood vasculitis hospital burden in Spain (1997-2011), considering type of disease, hospitalization rates and time trends. Data were obtained from the National Discharges Basic Minimum Data Set (National Patient Data Base). Inpatient events of children younger than 15 years of age were analyzed. Principal diagnosis of vasculitis were selected according Ninth Revision of the International Classification of Diseases: Takayasu arteritis, Polyarteritis nodosa, Kawasaki disease, Wegener`s granulomatosis, Churg-Strauss syndrome, and Henoch-Schönlein purpura. A total of 14518 children hospitalizations related to vasculitis were identified in Spain from 1997 to 2011. The average hospitalization rate for children was 13.33±1.71 per 100,000. Henoch-Schönlein purpura and Kawasaki disease were the most common type of vasculitis, hospitalization rates were 11.00 and 3.97 per 100,000 children, respectively. Other vasculitis hospitalizations are much rare in childhood. Average length of stay was 6.04 days and estimated cost per inpatient hospital care was 2,847€. Hospital case fatality rate was 0.05% for overall vasculitis. In conclusion, epidemiological data of childhood vasculitis are useful both to health decision-making and to identify research priorities.

Public health research on rare diseases.

Despite the low prevalence of Rare Diseases (RD), over 30 million EU citizens suffer from these conditions. This paper summarizes some aspects of these life-threatening chronic and debilitating diseases that usually require long term specialist care and costly formal and informal surveillance. Epidemiology does have an important role to play in the field of RD, since it provides appropriate methods and tools for assessing exposures and health outcomes. In this regard, the utility of registries, biobanks and population-based surveillance systems are discussed. The lack of effective diagnoses and treatments in RD patients often underlies their shortened life expectancy and quality of life. Due to the limited number of patients and the scarcity of relevant knowledge and expertise, coordination at European level is probably the best way of pooling the very limited resources available and provides a very high added-value. RD require the combined efforts of health and social care professionals, politicians, managers and researchers to increase the availability of effective disease management tools to improve care and to extend both life expectancy and Health Related Quality of Life.

[Rare diseases. Concept, epidemiology and state of the question in Spain]. / Enfermedades raras. Concepto, epidemiología y situación actual en España.

Rare diseases are those whose prevalence is below 5 cases per 10,000 inhabitants in the European Community. Most cases are diagnosed during paediatric age due to their genetic origin, while some others are congenital malformations. Nevertheless, a higher prevalence is seen during adulthood as most of the former diseases are very severe and patients die during childhood. At the same time, higher survival rates are related to some chronic rare diseases in adults. The Spanish Network of Research Epidemiology for Rare Diseases (REpIER) developed the first atlas showing the geographical distribution of rare diseases in Spain, assessed the Spanish rare disease registries, contributed to the further development of regional plans on rare diseases, as well as to social and health actions, and established the real group of needs to be solved. These have been included in the Communication of the European Commission on Rare Diseases as well as in the Spanish Senate Presentation.

Autism, the big unkown.

Autism is a common disorder of childhood. Yet, it often remains unrecognized and undiagnosed until or after late preschool age because appropriate tools for routine developmental screening and screening specifically for autism have not been available. Paediatricians have an important role in early recognition and evaluation of autism spectrum disorders because they usually are the first point of contact for parents. It is important that paediatricians are able to recognize the signs and symptoms of autism spectrum disorders and have a strategy for assessing them systematically. But paediatricians have also a role in chronic management of these disorders. The objective of this paper is to show a general view of the autism spectrum disorders (ASD) state of knowledge nowadays as well to stress the need of early detection and treatment of these disorders in order to improve better evolution and prognosis.

[Huntington's disease mortality in Spain in the period 1981-2004]. / Mortalidad por la enfermedad de Huntington en Espana en el periodo 1981-2004.

INTRODUCTION: Huntington's disease (HD) is an autosomic dominant neurodegenerative disease characterized by neuromuscular, cognitive and psychiatric symptoms. AIM: To analyze the mortality trend for HD from 1981-2004 in Spain. PATIENTS AND METHODS: Both crude and specific rates adjusted to the European population were used to show the evolution of mortality. Rates are showed by age and gender per million of inhabitants. Joinpoint regression model was used to analyze mortality trends. RESULTS: 866 deaths under HD codes were recorded in Spain during the study period (452 males and 414 females). Adjusted rates ranged from 0.64 in 1981 to 1.65 in 2004 in males and from 0.40 in 1981 to 1.16 in 2004 in females. The trend of the mortality rates in both genders followed a slight and steady increase during the whole period and dramatic changes were not detected. The average yearly percentage of this increase was 3.76% in males and 3.67% in females. CONCLUSIONS: The study has showed a yearly age adjusted mortality rates increase close to 4%. No differences have been seen between males and females. The follow up of this trend should be monitored to test if it stabilizes or it rises.

[Good practice guidelines for the treatment of autistic spectrum disorders]. / Guia de buena practica para el tratamiento de los trastornos del espectro autista.

INTRODUCTION: Due to the inexistence of an aetiology-based intervention for autistic spectrum disorders (ASD) families and professionals are exposed to diverse and sometimes conflictive recommendations when they have to decide the most adequate alternative for treatment. AIM: To elaborate treatment guidelines agreed by consensus at the ASD Study Group of the (National) Institute of Health Carlos III. DEVELOPMENT: Information about treatment of ASD was searched and gathered through available evidence based medical (EBM) databases. The data generated was complemented with practice parameters published elsewhere, reports from prestigious international institutions, focus oriented searches in PubMed and, finally, the opinion and experience of a multidisciplinary Study Group with extensive experience in treating ASD in Spain. Most popular treatment methods were reviewed as well as the common elements to be considered in successful support programs. CONCLUSION: No simple treatment algorithm can be produced at this time, and the level of available evidence based recommendations are in the weaker degrees of EBM classifications. Nevertheless, there is widespread agreement to stress that education, with special incidence in the development of communication and social competence, with the addition of community support are the main means of treatment. They can be complemented, depending on individual needs, with medication, behavioural approaches and cognitive-behavioural therapy for associated psychological problems in persons with higher cognitive level. Support to families and community empowerment are essential elements for the quality of life of persons with ASD.

Social/economic costs and health-related quality of life in patients with juvenile idiopathic arthritis in Europe.

OBJECTIVE: The aim of this study was to determine the economic burden from a societal perspective and the health-related quality of life (HRQOL) of patients with juvenile idiopathic arthritis (JIA) in Europe. METHODS: We conducted a cross-sectional study of patients with JIA from Germany, Italy, Spain, France, the United Kingdom, Bulgaria, and Sweden. Data on demographic characteristics, healthcare resource utilization, informal care, labor productivity losses, and HRQOL were collected from the questionnaires completed by patients or their caregivers. HRQOL was measured with the EuroQol 5-domain (EQ-5D-5L) questionnaire. RESULTS: A total of 162 patients (67 Germany, 34 Sweden, 33 Italy, 23 United Kingdom, 4 France, and 1 Bulgaria) completed the questionnaire. Excluding Bulgarian results, due to small sample size, country-specific annual health care costs ranged from €18,913 to €36,396 (reference year: 2012). Estimated direct healthcare costs ranged from €11,068 to €22,138; direct non-healthcare costs ranged from €7837 to €14,155 and labor productivity losses ranged from €0 to €8715. Costs are also shown to differ between children and adults. The mean EQ-5D index score for JIA patients was estimated at between 0.44 and 0.88, and the mean EQ-5D visual analogue scale score was estimated at between 62 and 79. CONCLUSIONS: JIA patients incur considerable societal costs and experience substantial deterioration in HRQOL in some countries. Compared with previous studies, our results show a remarkable increase in annual healthcare costs for JIA patients. Reasons for the increase are the inclusion of non-professional caregiver costs, a wider use of biologics, and longer hospital stays.

Cardiac abnormalities in the toxic oil syndrome, with comparative observations on the eosinophilia-myalgia syndrome.

Early in the course of studies of the Spanish toxic oil syndrome it was recognized that vascular lesions were a major problem, most logically attributable to endothelial damage by the toxic oil. However, most clinical attention has been directed to the pulmonary complications and the evolution into a scleroderma-like illness later. In this study of 11 victims of the toxic oil syndrome careful postmortem studies of the coronary arteries and conduction system and neural structures of the heart demonstrated major injury to all those components of the heart. Obliterative fibrosis of the sinus node in four cases resembled findings in fatal scleroderma heart disease, and in eight the cardiac lesions resembled those of lupus erythematosus. The more impressive pathologic features involved the coronary arteries and neural structures, which were abnormal in every heart. The arterial disease included widespread focal fibromuscular dysplasia, but there was also an unusual myointimal proliferative degeneration of both small and large coronary arteries in five patients, four of whom were young women. In two hearts, portions of the inner wall of the sinus node artery had actually detached and embolized downstream. Coronary arteritis was rarely found. Inflammatory and noninflammatory degeneration of cardiac nerves was widespread. Fatty infiltration, fibrosis and degeneration were present in the coronary chemoreceptor. In most respects these cardiac abnormalities resemble those described in the eosinophilia-myalgia syndrome caused by an altered form of L-tryptophan. In both diseases there is good reason to anticipate more clinical cardiac difficulties than have so far been reported, and even more basis for future concern, especially relative to coronary disease and cardiac electrical instability.

Toxic oil syndrome: a current clinical and epidemiologic summary, including comparisons with the eosinophilia-myalgia syndrome.

In the spring and summer of 1981, an epidemic of a new illness now referred to as the toxic oil syndrome occurred in central and northwestern Spain, resulting in some 20,000 cases, 12,000 hospital admissions and greater than 300 deaths in the 1st year of the epidemic. The initial onset of illness was usually acute, and patients presented primarily with a respiratory syndrome involving cough, fever, dyspnea, hypoxemia, pulmonary infiltrates and pleural effusions. While approximately 50% of patients recovered from this acute phase of the illness without apparent sequelae, the remaining patients developed an intermediate or chronic phase, or both, of illness involving severe myalgia, eosinophilia, peripheral nerve damage, sclerodermiform skin lesions, sicca syndrome, alopecia and joint contractures, among other findings. Epidemiologic and analytic chemical studies have clearly linked the toxic oil syndrome to the ingestion of oil mixtures containing rapeseed oil denatured with aniline. However, the precise identity of the etiologic agent within this oil has never been determined. Aniline itself did not cause the illness, but the causal agent may be a reaction product of aniline with some oil component. Although many aspects of disease activity in the involved patients have lessened with time, the ultimate consequences of their disease are not clear and are the subject of ongoing study. The recently described eosinophilia-myalgia syndrome in the United States clinically resembles the toxic oil syndrome.

[Best practice guidelines for the early detection of Autistic Spectrum Disorders (I)]. / Guía de buena práctica para la detección temprana de los trastornos del espectro autista (I).

INTRODUCTION: The interest in early detection of Autism Spectrum Disorders (ASD) lies in the accumulated evidence of the fact that an early customized intervention for children with an ASD and their families leads to an improvement of the child's prognosis in most cases. OBJECTIVE: To establish criteria and procedures for early identification of children at risk of ASD and to facilitate full diagnostic assessment and prompt referral leading to adequate support. Early detection of ASD is extremely important, since early specific individualized treatment for the child and his or her family leads to long-term improvement in many children' prognosis. DEVELOPMENT: Firstly, a critical appraisal of the situation of early detection of ASD in Spain is made after reviewing the scarce bibliography available on current screening and diagnostic practices in the country. Data generated by questionnaires received from 646 Spanish families is also taken into account. Secondly, the Study Group of the Instituto de Salud Carlos III recommends the screening and early diagnosis process to be followed, describing the necessary steps, the public services involved and the available screening and diagnostic tools. CONCLUSIONS: The Study Group draws the main conclusions regarding the situation of ASD early detection in Spain, and makes a consensus proposal for the detection procedures, including routine developmental surveillance and identification of children at risk for ASD by using sensitive and specific assessment tools.

[Best practice guidelines for the diagnosis of autistic spectrum disorders]. / Guía de buena práctica para el diagnóstico de los trastornos del espectro autista.

INTRODUCTION: The autism spectrum disorder (ASD) diagnostic process requires expertise both in the knowledge of autism as in teamwork strategies with different professionals, often working in different clinic services, and with parents. AIM: To recommend a consensus diagnostic procedure for ASD, that has been designed by the Study Group of the Instituto de Salud Carlos III. DEVELOPMENT: The reports emphasize the need to obtain a complete clinical history, covering personal, family and psychosocial antecedents; detailing the basic areas affected in ASD--social interaction, communication and restricted patterns of behaviour, activities and interests. Diagnostic tests to be used as a routine in all cases are described and analysed--including both psychoeducational and biomedical tests. Also, tests indicated in cases with suspected identifiable physical disorders are covered, as well as those medical tests to be used for research purposes only. CONCLUSION: The diagnostic procedure requires the implementation of a coordinated interdisciplinary assessment strategy, that needs to ensure the participation of professionals from very different fields in active collaboration with the family. Their role culminates in the preparation and delivery of a personalized report. Every diagnostic procedure needs to be accompanied by an action plan that includes immediate support to the person with ASD, as well as information to the family on resources and community initiatives in their living area.

[Best practice guidelines for research in autistic spectrum disorders]. / Guía de buena práctica para la investigación de los trastornos del espectro autista.

INTRODUCTION: Achieving a better knowledge of autism and other pervasive developmental disorders known as autistic spectrum disorders (ASD), poses a major scientific challenge. These disorders are some of the earliest and most severe psychopathological disorders in infancy; they include an heterogeneous group of conditions; its prevalence rate seems to be continually increasing and they generate a significant social impact. AIMS AND DEVELOPMENT: Nowadays, there is a current international agreement on the general requirements to be fulfilled by research projects and the priority areas to be considered when developing ASD high quality research. In Spain, although there are some established research groups with broad experience and expertise in these disorders, public funding opportunities and research development are still scarce. For this reason, the Study Group of the Instituto de Salud Carlos III has generated by consensus some Good Practice Guidelines for Research in ASD. CONCLUSIONS: After comparing priorities and recommendations from international reference documents with the results obtained after having carried out an exhaustive bibliographic revision of articles published in autism in the last 30 years by Spanish authors, methodological and ethical recommendations are established. Finally, structural deficiencies to be corrected and emerging research initiatives to be supported are identified.

Pharmacogenetic profile of xenobiotic enzyme metabolism in survivors of the Spanish toxic oil syndrome.

In 1981, the Spanish toxic oil syndrome (TOS) affected more than 20,000 people, and over 300 deaths were registered. Assessment of genetic polymorphisms on xenobiotic metabolism would indicate the potential metabolic capacity of the victims at the time of the disaster. Thus, impaired metabolic pathways may have contributed to the clearance of the toxicant(s) leading to a low detoxification or accumulation of toxic metabolites contributing to the disease. We conducted a matched case-control study using 72 cases (54 females, 18 males) registered in the Official Census of Affected Patients maintained by the Spanish government. Controls were nonaffected siblings (n =72) living in the same household in 1981 and nonaffected nonrelatives (n = 70) living in the neighborhood at that time, with no ties to TOS. Genotype analyses were performed to assess the metabolic capacity of phase I [cytochrome P450 1A1 (CYP1A1), CYP2D6] and phase II [arylamine N-acetyltransferase-2 (NAT2), GSTM1 (glutathione S-transferase M1) and GSTT1] enzyme polymorphisms. The degree of association of the five metabolic pathways was estimated by calculating their odds ratios (ORs) using conditional logistic regression analysis. In the final model, cases compared with siblings (72 pairs) showed no differences either in CYP2D6 or CYP1A1 polymorphisms, or in conjugation enzyme polymorphisms, whereas cases compared with the unrelated controls (70 pairs) showed an increase in NAT2 defective alleles [OR = 6.96, 95% confidence interval (CI), 1.46-33.20] adjusted by age and sex. Glutathione transferase genetic polymorphisms (GSTM1, GSTT1) showed no association with cases compared with their siblings or unrelated controls. These findings suggest a possible role of impaired acetylation mediating susceptibility in TOS.

Toxic oil syndrome: survival in the whole cohort between 1981 and 1995.

BACKGROUND AND OBJECTIVE: In 1981, toxic oil syndrome (TOS) appeared in Spain, affecting more than 20,000 persons and causing over 2500 deaths to date. Previous studies have addressed mortality only by gender and age. We analyzed possible prognostic factors in the survival of the cohort. METHODS: The study period was 1 May 1981 to 31 December 1995 (31 December 1995 was the cut-off date for survivors). The study population consisted of the entire cohort. Overall mortality and TOS-related deaths were studied. Kaplan-Meier method and Cox regression were used in the analyses. RESULTS: Among the 20,084 subjects in the cohort, 12,164 (60.6%) were women, and 7917 (39.4%) were men. Of the 1799 deaths, 958 (53.3%) were women, and 841 (46.71%) were men; of the 356 TOS-related deaths, 234 (65.7%) were women, and 122 (34.3%) were men. TOS was the leading cause of death among subjects <40 years of age. Among the TOS-related deaths, the shortest survival times were for women and subjects <40 years of age. The major disease manifestations had the highest relative risks (RR) (liver disease, RR 3.83; pulmonary infection, RR 1.54; motor neuropathy, RR 2.24; pulmonary hypertension, RR 3.19; and eosinophilia, RR 1.14.). CONCLUSIONS: The major clinical manifestations showed worse prognosis for overall and TOS-related mortality. Application of these results to the survivors will help clarify the validity of these conclusions.

Health status measurement in Toxic Oil Syndrome.

Toxic Oil Syndrome (TOS) is a previously unreported condition which affected more than 20,000 people in Spain in 1981 and whose natural history is unknown. In 1993-94, a stratified random sample of 1400 survivors was drawn to measure their health status through clinical examination and their self-perception of well-being through the Nottingham Health Profile Questionnaire (NHPQ). Two-thirds of the sample population responded; indirect estimates suggest that selection bias was limited. Clear and intermediate signs of neuropathy were found in one-fifth and one-half of the patients, respectively. One-fourth and one-sixth showed some degree of scleroderma and contractures. All conditions were more frequent in women than in men and in age >50 than in younger ages. Although no concurrent control group was included in the study, prevalences of these conditions are well above expectations and are largely attributable to TOS. NHPQ scores increased with age in both sexes up to age 50, after which they reached a plateau (with values around 48 in men and 62 in women). Scores were associated to the occurrence of peripheral neurological changes, contractures, and scleroderma-like conditions. A multivariate analysis indicated age, sex, and severity of neurological conditions as major determinants of the NHPQ scores. This overall pattern of findings is peculiar to TOS and differs from the typical post-disaster nonspecific syndrome.

Mortality among people affected by toxic oil syndrome.

The authors conducted a mailed questionnaire survey of a 5% sample of the cohort of 20,643 people officially recognized by the Spanish government as having had toxic oil syndrome, a previously undescribed illness that was epidemic in Spain in 1981. After three mailings of a letter and questionnaire, responses for only 66% of the sample had been received. Nevertheless, responses were obtained from virtually all remaining patients (or surrogates for them in the cases of patients that had died) when they were sought by telephone. In 1981, there was clear-cut excess mortality in the cohort (standardized mortality ratio [SMR] 6.51; 95% confidence interval [CI]: 3.92-10.17). During the period January 1982 through 7 March 1988, there was no statistically significant overall mortality excess except during the period 1982-1983 among people aged < 65 years (SMR 2.26; 95% CI: 1.03-4.29). Toxic oil syndrome substantially altered the patterns of mortality among affected people. Analysis of deaths by cause among the TOS cohort will be useful for further evaluation of the long-term impact of the TOS epidemic.

Toxic oil syndrome mortality: the first 13 years.

BACKGROUND: The toxic oil syndrome (TOS) epidemic that occurred in Spain in the spring of 1981 caused approximately 20000 cases of a new illness. Overall mortality and mortality by cause in this cohort through 1994 are described for the first time in this report. METHODS: We contacted, via mail or telephone, almost every living member of the cohort and family members of those who were known to have died in order to identify all deaths from 1 May 1981 through 31 December 1994. Cause of death data were collected from death certificates and underlying causes of death were coded using the International Classification of Diseases, 9th Revision. RESULTS: We identified 1663 deaths between 1 May 1981 and 31 December 1994 among 19 754 TOS cohort members, for a crude mortality rate of 8.4%. Mortality was highest during 1981, with a standardized mortality ratio (SMR) of 4.92 (95% confidence interval [CI]: 4.39-5.50) compared with the Spanish population as a whole. The highest SMR, (20.41, 95% CI: 15.97-25.71) was seen among women aged 20-39 years during the period from 1 May 1981 through 31 December 1982. Women <40 years old, who were affected by TOS , were at greater risk for death in most time periods than their unaffected peers, while older women and men were not. Over the follow-up period, mortality of the cohort was less than expected when compared with mortality of the general Spanish population, or with mortality of the population of the 14 provinces where the epidemic occurred. We also found that, except for deaths attributed to external causes including TOS and deaths due to pulmonary hypertension, all causes of death were decreased in TOS patients compared to the Spanish population. The most frequent underlying causes of death were TOS, 350 (21.1%); circulatory disorders, 536 (32.3%); and malignancies, 310 (18.7%). CONCLUSIONS: We conclude that while on average people affected by toxic oil syndrome are not at greater risk for death over the 13-year study period than any of the comparison groups, women <40 years old were at greater risk of death.

Toxic oil syndrome: traceback of the toxic oil and evidence for a point source epidemic.

Rapeseed oil denatured with aniline was the vehicle of the causal agent of the toxic oil syndrome (TOS) epidemic that occurred in Spain in 1981. Although the precise aetiologic agent remains unknown, researchers established that increasing concentrations of oleyl anilide and other fatty acid anilides were associated with an increased risk for disease. To examine the hypothesis that 5-litre plastic containers of rapeseed oil associated with TOS, and which contained oleyl anilide had a characteristic shape, we measured fatty acid, sterol and fatty acid anilide levels in oil from containers of different shapes. We identified 1673 bottles of oil that had been collected during the Spanish Government's oil exchange programme and linked these bottles to people with TOS as reported in the official government census of patients with TOS. Although rapeseed oil (identified by the presence of brassicasterol) was found in 798 (47.7%) of the 1673 bottles examined, contamination with fatty acid anilide occurred in only 329 (19.6%) of the 1673 bottles and 319 (97%) of the 329 were oil containers of the shape sold by RAELCA, an oil company in Madrid. The first aniline-denatured oil that RAELCA had purchased to be refined specifically for distribution was refined at the ITH refinery of Seville, and this oil has been most directly associated with the epidemic. Previous work has shown that the only toxic oil linked to a specific refinery was that associated with rapeseed oil from the ITH refinery in Seville, and the epidemic began shortly after this oil was delivered to RAELCA for retail sale. On the basis of these findings, we conclude that oil refined by ITH and distributed by RAELCA was the principal, and probably the only, oil responsible for the TOS epidemic. Information about the history and treatment of this oil may yield important clues towards identifying the aetiologic agent of TOS.

Manufacturing processes at two French rapeseed oil companies: possible relationships to toxic oil syndrome in Spain.

The toxic oil syndrome (TOS) epidemic that occurred in Spain in spring 1981 has been associated with the consumption of rapeseed oil that was denatured with aniline for industrial use but diverted for human consumption. The precise aetiologic agent in the oil responsible for the outbreak has not been identified. To learn more about possible contaminants and how the contamination might have occurred, we visited two French companies that process rapeseed oil and that were identified in Spanish administrative and judicial records as the ones exporting aniline-denatured rapeseed oil to Spain in 1981. With the apparently full and voluntary co-operation of personnel at both companies, we reviewed the processes involved in manufacturing, treating and transporting rapeseed oil, and we have summarized the information provided to us. Of particular importance is the finding that oil exported to Spain was taken from stock, the rest of which was sold for human consumption in the French domestic market, apparently without any adverse health effects. The differences between the oil exported to Spain and the oil sold as food in France were that aniline equivalent to 2% of the weight of the oil was added to most of the Spanish oil but not to that sold in France, and that contamination of the Spanish oil may have occurred in the tank trucks used for transportation to Spain, which had previously carried industrial chemicals. There is no assurance that the trucks were cleaned appropriately for transporting a food product before the oil was loaded for the journey to Spain. Since the clinical manifestations of TOS are not those of aniline toxicity, we conclude that the aetiological agent of TOS is likely to be one of the following: (1) a contaminant in the aniline, (2) a contaminant introduced during transportation, (3) a reaction product of normal oil components or materials used in refining with either aniline or the potential contaminants mentioned under (1) or (2) above.