Saturday, October 22, 2005

Reflecting on the Real Epidemic

I just took a break from the AWARES online conference http://www.awares.org/conferences/. I was thinking about some of the issues raised on the conference and I began to reflect on the Measles Mumps and Rubella vaccination’s theoretical link to autism. Specifically, I was thinking where we have been and where we are going. A lot has changed since the Wakefield, Murch, Anthony, Linnell, Casson, Malik, Berelowitz, Dhillon, Thomson, Harvey, Valentine, Davies, and Walker-Smith, (1998) research that began this issue.

I began to wonder if the scientific community (or anyone really) has the responsibility to speak up when they see a potential problem. So, do we?

I would answer “yes”. There are at least two reasons. The first is dedication to validity. In the absence of well controlled studies we have difficulty seeing how true a given proof is. And when there is no peer review it is hard for knowledgeable others to point out errors which could compromise our research.

The second reason is ethics. There is a guilt which comes, not from committing some transgression, but for failing to do something right. For scientists, this guilt tends to have a way of being felt when someone gets hurt from pseudo-science. I don’t wish to see someone hurt because I failed to do something.

This means I am free to keep an open mind and give other researchers a fair chance to show the merit of their work, but my mind doesn’t have to be so open that I accept theory in the absence of full experimental research.

Maybe it is especially our duty to speak up in treatments that have already hurt someone. If that is so, how have we fared?

The MMR debate has been heated at times; Wakefield et al. (1998) sparked a robust response from other members of the medical community, to say the least. The Lancet has had 26 replies/rejoinders on the issue since that time. Some of the criticisms were fairly serious and Lancet editors responded by expressing some regret that they were not aware of some of the problems in the study (Horton, 2004). The editors mention problems as diverse as threats to internal validity, ethics, and conflicts of interest.

Eventually, most the authors entered a retraction of their research Murch, Anthony, Casson, Malik, Berelowitz, Dhillon, Thomson, Valentine, Davies, and Walker-Smith (2004).

Since a considerable amount of time has been spent on what went wrong in this study, I would rather mention what went right. Beyond a doubt the fact that this research was submitted for peer review (and was subsequently taken to task by others) showed responsibility on the parts of the authors. The retraction also indicates responsibility on the part of some of the authors.

Anyone can be right, but it takes some integrity to admit to being incorrect. I have been told that part of being a scientist is looking stupid sometimes and that if one can not look stupid, one is not doing science. I don’t like the phrasing, but I agree. Looking stupid is emotionally difficult; I don’t envy Murch et al. (2004), but that is part of being a scientist; you agree that you were incorrect and why, and hope that you didn’t hurt anyone in the process, then you go home and laugh or cry a little about it.

Any time I hear others wonder about the necessity of peer review I simply think about Murch et al. (2004) and I am suddenly grateful for it.

I wouldn’t say this is a happy ending though. The scare produced by this research and subsequent promotion dropped the MMR vaccine usage in the United Kingdom. Measles cases rose, and the proper deployment of this vaccine is only now beginning to recover. This research is still considered valid in some portions of society on both sides of the Atlantic. In Montreal Canada, an autism society president claimed measles never killed anyone (Dawson, 2003). This is quite incorrect. The death rate for measles in developing countries is near 25% and while measles is rare in developed countries, it still kills 1-2 per 1000 cases (
http://www.cdc.gov/nip/publications/pink/meas.pdf#search='cdc%20measles%20death%20rate'). There was an undisputed US measles epidemic in 1989-1991, mostly among minority pre-school aged children who were not vaccinated. 123 deaths resulted (with the majority being children).

Dr. Wakefield, who was the lead author of the MMR study and continues to support it as valid, will face an inquiry this summer as to whether he is fit to practice medicine.

I wonder sometimes if future epidemics of infectious disease will be triggered by a current epidemic of irresponsibility.

Notes


The phrase "epidemic of irresponsibility" is taken from the subtitle of Dawson (2003) which is cited just below.

References

Dawson, M. (2003). September 3, 2003. Bettleheim’s worst crime.
http://www.sentex.net/~nexus23/md_01.html.
Accessed October 22, 2005.

Horton, R., (2004). A statement by the editors of the Lancet. Lancet, 363, 820-1.

Murch, S., Anthony, A., Casson, D., Malik, M., Berelowitz, M., Dhillon, A., Thomson, P., Valentine, A., Davies, S., & Walker-Smith, J. (2004). Retraction of interpretation, 363, 750.

Wakefield, A., Murch, S., Anthony, A., Linnell, J., Casson, D., Malik, M., Berelowitz, M., Dhillon, A., Thomson, M., Harvey, P., Valentine, A., Davies, S., & Walker-Smith, J. (1998). Heallymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children. Lancet, 351, 637-641.

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