On autism, antibiotics, and vaccination.

Judy Wilyman writes:

On the 27th August 2012, the ABC ran a story on Four Corners titled ‘The Autism Enigma – is it genetics or the environment?   Autism Spectrum Disorders (ASD), the fastest growing developmental disorder in the western world, is a genetic condition which can be ‘switched on’ by environmental factors – often a chemical. Hence this condition was very uncommon in the early 20th century but has become an ‘epidemic’ in the 21st century. So what is the environmental factor that children are being universally exposed to in the western world?

Gernsbacher, Dawson and Goldbacher, Current Directions in Psychological Science, 14:2, pp. 55–58, April 2005, write:

According to some lay groups, the nation is experiencing an autism epidemic—a rapid escalation in the prevalence of autism for unknown reasons. However, no sound scientific evidence indicates that the increasing number of diagnosed cases of autism arises from anything other than purposely broadened diagnostic criteria, coupled with deliberately greater public awareness and intentionally improved case finding.

Further, Judy writes:

Four Corners suggested one factor causing this neurological damage might be the use of antibiotics.

A researcher at the Olga Tennison Autism Research Centre, La Trobe University, writes:

In speaking with the Four Corners researcher, on behalf of the Australasian Society for Autism Research, my first note of caution was that this is but one theory among many others put forward to explain the enigma that is autism. Indeed the impact of coverage of one theory, in isolation, is not helpful in informing the public who are indeed concerned about the increased prevalence of ASDs. To their credit, at our behest, the program removed some of the more wildly controversial and unsubstantiated claims. Despite these changes, The Autism Enigma’s main research findings, while of genuine interest, are sorely in need of independent replication. Some children with an ASD appear susceptible to gastrointestinal (GI) conditions. Indeed, Autism Speaks, the US based organization, funded the development of evidence-based guidelines for physicians to use to screen, assess, and treat GI conditions in children with ASD, recognising that their treatment can improve the quality of life for these children and their families.

However, it is important to recognise that the research presented on the PBS program is in the early stages, with the findings to date providing no evidence thus far that gut bacteria and their by products cause ASDs, even a subgroup of them, or that treating the gut can alleviate the specific symptoms of ASD.

I thus expressed disappointment that research in the early phases of discovery is receiving recognition (from a credible program like Four Corners) prior to the much needed replication from other laboratories.

Like the discredited MMR vaccine theory, the gut theory presented in this program targets those cases of ‘regressive’ autism, whereby young children develop symptoms after a period of seemingly typical development. Regression most commonly occurs between 15- to 20-months of age, and these children tend to have more severe symptoms. Whether these are the children who are most vulnerable to GI problems remains to be determined. One would assume, on the basis of the claims made in the program, that this would be one of the first questions addressed by those promoting the ‘gut theory’ Certainly, the argument made in the program that it is the gut microflora that causes the brain changes associated with ASDs cannot be addressed without ascertaining this connection, such that this relationship and the theory remain largely unsubstantiated.

Further, Judy writes:

Four Corners suggested one factor causing this neurological damage might be the use of antibiotics. A source of antibiotics for children is childhood vaccines. The antibiotics Neomycin and Polymyxin are present in many of the 12 vaccines that are given to children before 1 year of age and the mercury compound Thiomersal (a neurotoxin) is present in ‘trace’ amounts in the Hepatitis B vaccine given to infants from day 1 after birth. It is also present in some influenza vaccines. Scientists have not established a safe level of mercury in humans (this would be unethical) and it is known that even chemicals in very low doses can cause serious health effects – particularly when combined with other antibiotics and preservatives e.g. aluminium hydroxide/phosphate or Borax (in Hib and HPV vaccines) etc.Whether this source of antibiotics is a major or a minor source is debatable. Consider the following factors:

• Children are receiving not 1 or 2 vaccines but many doses of 12 – 13 vaccines in the first year of life
• Infant body systems are still developing during the first year of life and chemicals are many times more toxic in an infant’s body than in an adult’s body
• Chemicals injected into the human body bypass all the natural defense mechanisms

Barbara E Eldred, Angela J Dean, Treasure M McGuire and Allan L Nash, The Medical Journal of Australia, 184:4, pp. 170–175, write:

A recent study assessed whether multiple vaccinations can lead to mercury accumulation.6 In full-term infants exposed to vaccines containing thiomersal, mercury concentrations detected in blood (range, 2.85–20.55 nmol/L) were well below the level thought to be associated with adverse effects. Additionally, ethylmercury appears to be eliminated via the gastrointestinal tract soon after exposure (estimated half-life, 7 days).6Because the developing fetus and low birthweight babies are more vulnerable to toxic effects of mercury, it has been suggested that exposure to vaccines containing thiomersal at time of birth may pose some risk in very low birthweight premature infants.6 To minimise any potential risk, all vaccinations in the Australian Standard Vaccination Schedule for children younger than 5 years are now thiomersal-free or contain only trace amounts.7

Also relevant, is the fact that ethyl mercury is different to mercury is different to methyl mercury, in the same way that sodium is quite different chemically to sodium chloride, with obviously different effects from consuming them. Of course it is unethical to give someone mercury in levels to test toxicity, however our knowledge of mercury (and various other mercury-containing chemicals) comes from studying those who’ve accidentally ingested it, animal proxies, in vitro studies, etc. (and I note the limitations of inferring from in vitro and animals to humans). Of course, ethyl mercury wouldn’t be used if it wasn’t safe, and as discussed above the amounts that were used in the past are known to be at safe levels, for a typical vaccination schedule, and we’re now going above and beyond that in using trace amounts.

On the use of antibiotics in vaccinations, Eldred et al. write:

Antibiotics such as neomycin and polymyxin B are often used to prevent bacterial contamination during vaccine manufacture;5 they may contribute to systemic allergic reactions, including anaphylaxis, or local skin reactions.13 Previous skin reactions to neomycin are not considered a risk factor for anaphylaxis and are not a contraindication for use of neomycin-containing vaccines.13 Neomycin concentrations may vary between vaccines, but most contain only residual amounts.14

i.e. it’s not debatable as to the amount used, it’s very low (and particularly if you consider the amount in relation to the doses given in a typical course of antibiotics).

Judy further writes:

Governments have not funded the studies that would prove combining vaccines in infants is safe therefore it is essential that this medical procedure should remain completely voluntary: government’s (sic) should not link this procedure with financial incentives or require conscientious objector’s forms (sic) to be signed by a doctor to refuse any vaccine

Whether Eldred et al. received any Government funding is not stated in their paper, they only state no competing interests (though given they’re researchers in Australia, it is probable that they receive indirect funding by virtue of working in academia), their study does consider combinations of vaccines.

It is still voluntary, despite financial incentives (which are still given to conscientious objectors). I would have thought that requiring conscientious objectors’ forms be signed by a doctor, after an opportunity to receive information on vaccinations from someone medically trained, to be quite sound.

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