Got Asthma? Thought About Inviting A Few Hookworms To Move In?
- Is it the right time?
- Is anyone watching?
- Does your partner even want to?
- Is your breath fresh?
- Then you lean in and just go for it!!!
- What's the hygiene hypothesis?
Chronic infestation with helminths may also confer protection, but short-lived episodes of infestation may exacerbate atopic disorders.Now, there was an interesting sidelight on the hygiene hypothesis earlier this year with the Increased Levels of IgE and Autoreactive, Polyreactive IgG in Wild Rodents study which is well summarised in From Good Hygiene Comes Bad Allergies. We also learned that Weinstock and his colleagues experimented with treating people with active Crohn's Disease with a solution of pig whipworm in Gatorade. The treatment did bring about remission suggesting that:
it is possible to downregulate aberrant intestinal inflammation in humans with helminths.I reported that I gave myself the horrors by recalling this on a recent sleepless night. I had the idle and frivolous thought that some hapless helminth for which I have a specie-ist revulsion might down-regulate aberrant airway inflammation in humans (e.g., asthma). I doubt it - but, as I admitted at the time, I have nothing on which to base that doubt apart from prejudice.
I was intrigued and repulsed in equal measure when I came across an anecdote by Luckbeaweirdo who claimed to have cured his severe asthma and hayfever by using hookworm. He didn't pull any punches about what happens during infestation:
Walking barefoot in soil contaminated with feces (the source of hookworm eggs/larvae) is the most common method of exposure. The other is inadvertent ingestion of contaminated feces. Note that the hookworm cannot proliferate in your gut, you can only increase your infestation level by coming into skin contact with larvae or ingesting contaminated feces. After skin penetration, the venous circulation carries larvae to the pulmonary bed, where they lodge in pulmonary capillaries. Within 3-5 days, the larvae break through into alveoli and travel up the ciliary escalator from the lungs into the bronchi, the trachea, and the pharynx. This often causes a violent cough such as I experienced. It woke me up, continued for about two hours and was so violent at its peak that I vomited into my mouth. Upon reaching the pharynx, larvae are swallowed and gain access to the GI tract. Once in the GI tract, worms attach to the wall of the lower intestine and begin to feed on the blood of the host. They are intestinal leeches.He helpfully describes the practical method that he has devised to reinfest himself without having to return to Cameroon. I have refrained from quoting any of the most gruelling parts of this interesting piece but thought at the time that few people would be desperate enough to run the risk of collateral infestations and infections from acquiring hookworms, almost literally, in the field.
Now, the BBC has publicised a call for volunteers for a hookworm study in the UK. Researchers are trying to find out if they can use the hookworms or their products to lesson the impact of allergies, asthma or hayfever. I have previously wondered if the rise in the prevalence of asthma and allergies in Africa is linked to improved sanitation and less exposure to helminths. Professor John Britton is leading the research and has previously reported that, in Ethiopia, people living in the countryside are less likely to have allergies but more likely to have parasites.
We found higher levels of asthma in the towns and we believe this was partly down to a lower number of people carrying parasites.The hygiene hypothesis and its variations suggest that people in industrialised countries do not encounter enough challenges to their immune systems to encourage its robust development or maintenance. It is logical to consider that if we co-evolved with parasites, and they contributed to our adaptation to our environment, then ridding ourselves of them over too short a time-period to allow for necessary adaptation can cause further problems. However, I must still confess to queasiness in the matter, despite the rationality. We have to use helminths to distract an over-sensitive immune system? We can't just play it show tunes and smile fetchingly?
The mechanism by which the hookworms are thought to 'distract' the immune system is not well-understood but I can understand why people who have life-threatening allergies or asthma would consider what seems like extreme measures.