Tuesday, June 30, 2020

THINKING ABOUT VIRUSES

Many years ago after reading about a scientist who was interested in the many and complex variations on the gene codes we call “viruses” who have escaped the machinery of cells by invading pre-existing entities, and who had dedicated himself to acquiring samples from jungle hunters, I proposed a sort of vending machine at the beginning of each trail.  The idea was that the person emerging by that trail would pause enough to stick his (or her) finger into a hole that would take a blood sample.  Then the machine would spit out some kind of valuable token for exchange or wanted as an object, a bullet or a food.  Even a condom.

Everyone thought this was a ridiculous idea because no one worried about viruses that much.  The reason was that they didn’t realize how much they permeate our lives and how fluid they are.

I’m trying to understand viruses, but no sooner do I figure out one thing than they discover some new aspect.  For instance, I had learned about the four nucleic acids, than it turns out that RNA (single strand nucleic acids) has a different fourth nucleic acid than DNA (double strand nucleic acids).

Nucleic acids are the biopolymers, or small biomolecules, essential to all known forms of life. The term nucleic acid is the overall name for DNA and RNA. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. If the sugar is a compound ribose, the polymer is RNA (ribonucleic acid); if the sugar is derived from ribose as deoxyribose, the polymer is DNA (deoxyribonucleic acid).Nucleic acids are the most important of all biomolecules. “  (Britannic instead of Wikipedia)


Pictures in the website linked above.  I’ve always thought of viruses as little flecks hardly big enough to have “structure” but I could not have been more wrong.  They are zoomorphic, inventive, invasive attempts at life that went wrong, or maybe primitive life that couldn’t quite get it together.  Or maybe they’re jokes or caught in transit, merely becoming instead of being.  The scientists have a sense of humor about it.  The very largest ones are called “Mimiviruses” or “Pandoraviruses.”  I imagine Mimi and Pandora were not amused.

The point is that they are not necessarily jungle hunters in the traditional sense.  Today’s mega-city IS a jungle and both Mimi and Pandora live there.


Comments from this website follow.

“Ebola, sars, Zika and Rift Valley fever. But it also included “Disease X”.  This illness, caused by a pathogen never before seen in humans, would, the panel said, emerge from animals somewhere in a part of the world where people had encroached on wildlife habitats. It would be more deadly than seasonal influenza but would spread just as easily between people. By hitching rides on travel and trade networks, it would journey beyond its continent of origin within weeks of its emergence. It would cause the world’s next big pandemic, and leave economic and social devastation in its wake.”
. . . . . . . . .  

“The first layer is a worldwide effort to find and track the hundreds of thousands of as-yet-unseen pathogens that might threaten human health. The second is the monitoring of blood samples and other indicators from people living in places where new diseases are most likely to emerge. The third is a concerted programme that employs all the data thus collected to get a head-start in the development of drugs and vaccines that might be used to meet an emerging disease halfway.”

. . . . . . . 

“In 2004, however, a highly pathogenic strain emerged and began to spread across South-East Asia, killing tens of millions of birds. By the middle of 2005 this version of the virus had infected wild geese, which took it into Europe, India and Africa. That year, 98 people were infected, and 43 of them died—a death rate severe enough for David Nabarro, then co-ordinator of the un’s response to influenza, to issue a warning that an unchecked h5n1 outbreak could kill up to 150m people. In 1968 a less pathogenic strain of flu, which had originated in the same area, killed 1m people when it spread around the world. In 1957 a still-earlier relative killed 1.1m. h5n1 was considerably more lethal than either.”

. . . . . . . . . .

“PREDICT ran for just over a decade. Scientists working with local teams in 30 countries collected around 170,000 samples from people and wild animals, mainly non-human primates, bats and rodents. In the process they discovered 1,200 new viruses belonging to families known to have the potential to infect people and cause epidemics. Among these were more than 160 potentially zoonotic coronaviruses.”

 . . . . . . . 

“Among other things, having a registry of such risks might make it possible to identify hotspots where an unhealthy number of the conditions for zoonoses coexist. The predict programme’s risk registry includes virological, ecological and sociological factors. Viruses which store their genes as rna, for example, are categorised as more risky than dna viruses, because of their increased ability to mutate. Viruses already found in more than one host are also flagged up. They clearly have an adaptive knack. And being adapted to a species reasonably close to Homo sapiens matters too. A virus able to reproduce in the cells of one species will, other things being equal, have a better chance of adapting to life in a related species than an unrelated one. siv did not have to change all that much to become hiv. Reptile viruses, by contrast, are less of a threat.”

. . . . . . .

“Besides being the original reservoirs of sars-cov and sars-cov-2, bats also harbour another coronavirus, mers-cov, which causes Middle Eastern respiratory syndrome, an illness first detected in 2012. They are also the source of the virus which causes Ebola and of the hendra and nipah viruses which, over the past three decades, have led to small outbreaks of deadly respiratory and brain infections in Australia and South-East Asia.”

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