SATT recently prepared the following for several friends asking where and how regarding the virus.
But first, view How the Virus Got Out by New York Times
It’s believed COVID-19 started in a wet market in China. These markets are outdoor stalls squeezed together to form narrow lanes, live and dead animals and ripe produce are purchased. A stall selling caged chickens may abut a butcher counter, where meat is chopped. Wet markets put people and live and dead animals — dogs, chickens, pigs, snakes, civets, and more — in constant close contact. Poorly regulated, wet markets mixed with illegal wildlife create opportunity for viruses to spill over from wildlife hosts into the human population (Wildlife Conservation Society).
The following is from a UC Berkely study that explains COVID-19, which is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2)
A study of cultured bat cells shows that their strong immune responses, constantly primed to respond to viruses, can drive viruses to greater virulence. Modelling bat immune systems on a computer, the researchers showed that when bat cells quickly release interferon upon infection, other cells quickly wall themselves off. This drives viruses to faster reproduction. The increased virulence and infectivity wreak havoc when these viruses infect animals with tamer immune systems, like humans.
This makes bats a unique reservoir of rapidly reproducing and highly transmissible viruses. While the bats can tolerate viruses like these, when these bat viruses then move into animals that lack a fast-response immune system, the viruses quickly overwhelm their new hosts, leading to high fatality rates.”Some bats are able to mount this robust antiviral response, but also balance it with an anti-inflammation response,” said Cara Brook, a postdoctoral Miller Fellow at UC Berkeley and the first author of the study. “Our immune system would generate widespread inflammation if attempting this same antiviral strategy. But bats appear uniquely suited to avoiding the threat of immunopathology.”The researchers note that disrupting bat habitat appears to stress the animals and makes them shed even more virus in their saliva, urine and feces that can infect other animals.”Heightened environmental threats to bats may add to the threat of zoonosis,” (See Note definition below)
There is a term I use in teaching others about how trout differ. Stock,wild,native are categories related to the degree of change humans have made upon trout. The term is anthropogenic, which designates an effect or object resulting from human activity.
The study above states “the researchers note that disrupting bat habitat appears to stress the animals and makes them shed even more virus in their saliva, urine and feces that can infect other animals.” This means human activity including climate change distrupts bat habitats. Maybe we are the cause of COVID-19.
Note: “Animals can sometimes carry harmful germs that can spread to people and cause illness – these are known as zoonotic diseases or zoonoses. Zoonotic diseases are caused by harmful germs like viruses, bacterial, parasites, and fungi. These germs can cause many different types of illnesses in people and animals, ranging from mild to serious illness and even death. Animals can sometimes appear healthy even when they are carrying germs that can make people sick, depending on the zoonotic disease. Zoonotic diseases are very common, both in the United States and around the world. Scientists estimate that more than 6 out of every 10 known infectious diseases in people can be spread from animals, and 3 out of every 4 new or emerging infectious diseases in people come from animals. Because of this, CDC works 24/7 to protect people from zoonotic diseases in the United States and around the world.”
