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We have had a lot of excitement the last couple of weeks, what with Halloween and the midterm election.  Let’s relax a little bit with [checks notes] the horrifying story of a dare gone wrong which lead to the tragic death of a young man? What?? Who chooses this content? Gah!

Well, anyway, this story comes from Australia where, in 2010, teenager Sam Ballard was hanging out with his mates (which is what Australians call friends) and drinking some wine when a small garden slug crawled across his friend’s patio.  In a manner instantly recognizable to anyone familiar with teenage boys, the young men jokingly dared one another to eat the tiny mollusk, and, to show them up, Sam gulped down the tiny creature.  This proved to be an irreversible, fatal error.  Soon Sam’s legs began to hurt and then he fell into a coma for more than a year.  Sam regained consciousness but he was paralyzed and subject to a host of dreadful ailments which ultimately killed him a few days ago.

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There may be a moral to this sad horror story (particularly in the States where, in 2016, 46.4% of the electorate made a seemingly trivial– albeit disgusting–choice which is paralyzing and killing our nation), however there is certainly a scientific explanation.  Slugs can carry rat lungworm disease which is caused by a parasitic nematode called Angiostronjilus cantonensis (crustaceans and frogs can carry the worm as well).  In the happy normal course of existence, the slugs, crabs, and frogs (and thus the nematodes) are eaten by rats which develop lungworm infection in, you know, their lungs.  They excrete droppings infected with lungworms which in turn are eaten by slugs and small invertebrates which are then eaten by rats and frogs. This nematode was originally indigenous to Southeast Asia and nearby Pacific Islands, however as the climate changes and humans move around (taking rats and nematodes with us, apparently) the microscopic worms have spread to Australia, Africa, the Caribbean, and the United States.

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I enjoy nature and have a deep appreciation of ecosystems and all of their diverse inhabitants, yet somehow the preceding paragraph makes me want to burn away rats, frogs, slugs, and nematodes with cleansing fire and live like Howard Hughes.  Speaking of fire, if you must eat rats, frogs, garden slugs, small invertebrates, or nematodes,  you should thoroughly cook them first.  I guess that is a really useful and ancient pro tip for success in life.

There is a bigger reason I am telling this upsetting story though.  Strange microscopic bits of one ecosystem have a way of getting into other ecosystems and causing complete havoc. Rat lungworms don’t even really have anything to do with humans, but when mistakenly consumed by us, they do not end up in our lungs but instead in our brains (btw, this is bad news for the nematodes too, which are unable to complete their natural revolting nightmare life-cycle).

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Paleontologists have long speculated that this sort of mix-up is a factor in many mass die-offs and other large scale extinction events.  Fossil evidence for such things however is exiguous, so they have to look for analogous situations in the modern world (like the case of poor Sam Ballard) or go digging in the genomes of modern living organisms.  These genomes often do carry information about a long strange history of fighting off weird viruses, pathogens, and microscopic invaders, but it is not easy to figure out the specifics within the Rube Goldberg-style world of immune cell epigenetics. Zookeepers and stockpeople (and their veterinary pathologists), however, know all about these sorts of dark misconnections from horrible sad incidents which happen all the time in farms and zoos.  I suppose I am bringing this up because I suspect that climate change, near instant international travel, and modern supply chains, will continue to amplify the problem (I have touched base concerning this in my essays about parasitoid wasps, but these may be a touch abstract, so I am telling Sam Ballard’s story).

We could spend more time and money understanding biology properly to get ahead of these trends (which will be greatly magnified in any synthetic ecosystems which we build on Earth or beyond), or we could continue with our current choice of giving all of our resources to corrupt billionaires to hoard.  While we ponder that choice, let us extend our deepest condolences to the Ballards for their terrible loss.  I am also going to clean my kitchen with bleach and maybe take a shower.

 

Yesterday’s post concerned smallpox, one of the most dreadful scourges to ever afflict humankind.  I shied away from writing about the physiological aspects of the disease–which is caused by two viruses, Variola major and Variola minor–because the symptoms are absolutely horrible (as I can fervently attest after some internet research involving photographs which were apparently taken in the cruelest depths of hell).  Smallpox was badly named.  It should have been called “deathrash” or “bloodskin” or “face-melt-fever”, but apparently Roman stoicism came to the fore and the Latin name merely means “spotted” or “pimple.”  Not only did smallpox effectively kill off the native population of the new world (and later of Australia, which experienced a similar plague), but for thousands of years it regularly culled a sizable hunk of humanity from Africa, Asia, and Europe.  Like influenza, the smallpox co-evolved in response to our immune reactions to it, so, even in parts of the world where people had inherited some resistance, the pestilence sometimes flared into a full scale pandemic.

Death and the Child (Sebald Beham, woodcut, early 16th century)

But smallpox is gone (almost)!  Humankind joined together and beat one of the most horrible things we have ever faced.  Today the last remaining live smallpox viruses are imprisoned in laboratories in Atlanta and Koltsovo, Novosibirsk Oblast.

In grade school, we were taught that this stunning victory came about when an English physician named Edward Jenner realized that milkmaids who contracted a mild rash called cowpox became immune to smallpox.  By deliberately giving people cowpox, Jenner found a way of protecting them from the fatal smallpox.  Jenner thus invented immunology, one of the most useful and inexpensive forms of medicine.  His great work was taken up by subsequent generations of immunologists and physicians in allied fields who improved upon his findings.  Together they used national and international resources to immunize the world.  Smallpox was officially proclaimed to be eradicated in 1979.

Yet Jenner had antecedents who were not well appreciated because of the preconceptions and prejudices of the day, (also, by necessity, he worked with human subjects whose bravery went unheralded).  Jenner’s greatness is not diminished by looking back at the others who were involved in an epic struggle against history’s greatest killer.  There are descriptions of smallpox avoidance techniques in ancient Sanskrit texts from India dating back to 1000 BC, however scholars do not agree on whether these texts describe inoculation or not.  What is certain is that a medical text from Ming dynasty China does indeed describe an effective inoculation process.  The Douzhen xinfa  published in 1549 was written by Wan Quan, a pediatrician who believed that sunlight and fresh air were good for children (and that overfeeding and overmedicating were bad). Wan Quan described a method of variolation—by which means a healthy person was purposely infected with Variola minor, the less dangerous o the two forms o smallpox.  By the time of the Lonquing Emperor who reigned from 1567–1572 (and was the son of the addled Jiajing emperor) variolation was widespread–powdered smallpox scabs were blown up the noses of healthy children so that they would contract Variola minor.  This was effective in preventing smallpox, but it had a fatality rate of .05% to 2%–a dreadful margin (though nothing like the 30%+ mortality rate of smallpox pandemic).

Variolation gradually spread through the Chinese empire and through the Turkish and Islamic world, but it did not reach the attention of western medicine until the early 18th century.  Lady Mary Wortley Montagu was the wife of the British ambassador to the Ottoman Empire from 1716 to 1717 (as well as a sort of feminist pioneer, poet, and adventurer). After losing a brother to smallpox (and being disfigured by the disease) Lady Mary was eager for a means to protect her children from the scourge.  In 1718, the embassy surgeon inoculated her son and, based on the success of this procedure, she arranged for her daughter to be inoculated in 1721 (when the family was back in England).  The procedure attracted the attention of the medical establishment and the royal family.  Although many doctors were aghast at an “Oriental” procedure (which was being popularized by a woman, no less) the royal family intervened directly in the controversy when a smallpox epidemic swept England in the 1720s.  In order to fully test the safety of the inoculation, the King offered a full pardon to six (or seven?) condemned prisoners in exchange for undergoing variolation.  Not surprisingly the condemned prisoners chose an unknown medical procedure instead of the hangman’s rope, and when they survived they were duly freed.  Variolation was also tested on six orphan children–who also survived.  After these human tests, the royal children were inoculated against smallpox.

Lady Mary Wortley Montagu with her son, Edward Wortley Montagu, and attendants (Jean Baptiste Vanmour, ca. 1717, oil on canvas)

Inoculation spread quickly among the rich and powerful of Europe, but it was staunchly opposed by reactionaries and by churchmen (who believed it was contrary to God’s will).  Against such a background, came Jenner’s discovery of a cowpox based vaccine which was vastly safer than using live smallpox.  But even with the much safer vaccine, it was a long time before the immunologists started to win over many ignorant and superstitious people to the life-saving virtues of the vaccine (and nearly two hundred more years before they stomped out the loathsome blight of smallpox).

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