The following extract from the published literature clearly reinforces the authorís assertions that scientists need to adopt a holistic approach when investigating oilseed rape allergy syndrome.
The catalogue of failures in previous oilseed rape scientific studies and the poor media information handling and reporting is remarkably similar to the problems encountered during the initial research investigations into Toxic Oil Syndrome.
Toxic Oil Syndrome: Lessons Learned
The toxic oil syndrome epidemic shares many important features with other public health crises. Thus, we can refer to the way this epidemic transpired to apply the lessons learned from toxic oil syndrome to other mass illness situations in the future.
An adequate initial hypothesis is fundamental to abort an epidemic quickly. Although symptoms seen early in the epidemic may be limited to only one organ system, such as the lung in toxic oil syndrome, it is important to keep an open mind with regard to possible routes of exposure. This was a prominent contributing factor to the direction followed by the first case-control study carried out in Spain in 1981. Few questions were asked about foods or other items that might have been ingested, as the focus was primarily on respiratory and infectious agents. Thus, while a new disease or outbreak may initially appear to result from a specific cause (such as infectious, as was believed initially in toxic oil syndrome), the possibility of another etiologic agent (such as environmental) should not be excluded without thoughtful consideration. Failure to carefully weigh all possible causes when studying a disease of unknown origin can lead to delays in implementing preventive measures and treatment.
In a crisis situation such as the toxic oil syndrome epidemic, a case-control study design is the best method to assess the likely cause of the epidemic, because of the relatively short length of time required to perform one compared with other study designs, and because of the ease with which several hypotheses can be explored in the same study. Another important consideration when conducting a case-control study in this type of situation is to anticipate more than the usual amount of recall bias. Publicity was heightened during the toxic oil syndrome episode, and the public was bombarded with correct and incorrect information about the new disease, thus making it difficult in the long run for epidemiologists to recruit study subjects who were not somehow already biased. In the cases of both toxic oil syndrome and eosinophilia-myalgia syndrome, however, the strength of the association was so high that we do not believe even a larger than ususal recall bias would have changed the final result. In view of this, epidemiologists should do whatever possible to test their hypotheses before official announcements regarding a cause are made, thus avoiding this kind of bias as much as possible.
Another major problem in an epidemic such as toxic oil syndrome is to accurately determine the exposed population. As was the case with the toxic oil, some exposures may be very widespread, or their extent may not be determined before investigators identify the source or vehicle of exposure. Thus, when public authorities attempt to intervene, important epidemiologic information or evidence may be destroyed or damaged, leading to problems for subsequent investigators.
The crisis atmosphere that surrounds episodes such as toxic oil syndrome may also affect the quality of information collected during and after the acute phase of the epidemic. For a variety of reasons people who should be included in the cohort or patient registry may not be. Our experience with toxic oil syndrome suggests that the best solution to this problem is the establishment of only one centralized case register. Nevertheless, some misclassification is unavoidable. The total spectrum of the disease may not yet be evident, thus excluding legitimate cases, while in other instances some persons may be tempted to take advantage of a situation that they believe will be profitable by feigning subjective symptoms. To mitigate this effect, all possible patients should initially be registered, and enough information should be collected so that future attempts to categorize these patients have a better chance for success.
Collaboration across multidisciplinary lines is also an important issue when dealing with an outbreak of an unknown disease. Decisions regarding follow-up of sick or exposed people should be made contemporaneously with the epidemic, as this may prove one of the most crucial considerations for future research and treatment. In most cases, however, decisions that could affect future studies are not made in a systematic manner and, since the long-term evolution of the disease is not known, long-term follow-up of the cohort may not be an initial consideration unless a specific group of researchers takes on this responsibility independently.
Epidemiologists play a fundamental role throughout an epidemic. Teamed with clinicians, toxicologists, and specialists in other areas such as infectious disease, epidemiologists should take a lead in the development of a working hypothesis and in the design of the initial epidemic studies. The epidemiologistís role also includes defining both the possible exposures and the exposed population in detail, as well as providing advice on biologic and environmental sample collection. Later, continued collaboration between epidemiologists and scientists from other disciplines is central for development of additional study designs, assessment of biologic and environmental sample validity, selection of study subjects, and data analysis.
A little recognized role of epidemiologists in crises such as toxic oil syndrome, in addition to assisting public health authorities and advising in all phases of the investigation, is to make every effort to ensure the accuracy of data and other pertinent information, as situations of this type often have legal repercussions lasting well beyond the near term public health issues. Additionally, in spite of the complexity of crises such as toxic oil syndrome and the participation of scientists and others from many disciplines, comprehensive responsibility for the epidemic must be handled by only one group, typically the pertinent public health officials, including epidemiologists. Finally, while decisions to fund longterm research and follow-up activities may fall to political authorities, input from epidemiologists is essential to provide accurate information on which to base critical future health care decisions, including estimates of future health care system needs.
(Toxic Oil Syndrome: The Perspective After 20 years., Manuel Posada de la Paz., Epidemiologic Reviews, Vol. 23, No. 2. 2001)
Author - Armitage; copyright 2007