Total reported cases of the coronavirus rose to 40,645 this week, more than 40,000 of them in China. And while there are some cases in California, there are no suspected or confirmed cases of coronavirus in Siskiyou County, the Siskiyou County Department of Public Health stressed Monday.

A virus is often described as “a piece of bad news wrapped in an envelope.”

Transmission within certain animal species is not uncommon. Parvovirus, for example, originated with dogs and eventually decimated gray fox populations in parts of northern California and Siskiyou County.

But what is troubling for scientists studying the recent coronavirus outbreak in Wuhan, China, is the concern that it has spread from animals to humans.

It is not the first time.

From bats to snakes to camels, viruses have a unique ability to jump a species and then mutate depending on the host. Once established they can be deadly. The 1918 Spanish flu pandemic killed an estimated 50 million people worldwide. That was before a virus could travel the planet in a single day on an airplane.

Total reported cases of the coronavirus rose to 40,645 this week, more than 40,000 of them in China. And while there are some cases in California, there are no suspected or confirmed cases of coronavirus in Siskiyou County, the Siskiyou County Department of Public Health stressed Monday.

Dr. Christian Walzer, executive director of the Wildlife Conservation Society, said part of the problem stems from live animal markets, which “provide ideal conditions for the emergence of new viruses.” He believes the coronavirus started in just such a manner.

“If these markets persist, and human consumption of illegal and unregulated wildlife persists, then the public will continue to face heightened risks from emerging new viruses, potentially more lethal and the source of future pandemic spread,” he said.

Other viruses that have spilled over to humans from wildlife include severe acute respiratory syndrome (SARS) and Ebola fever. The process is known as “host switching.”

In a study completed by the American Society for Microbiology, researchers stated that it is rare for a virus to spread efficiently within a new host that was not previously exposed or susceptible. But when it does the results can be devastating.

HIV virus, also known as AIDS, is believed to have started with chimpanzees. It eventually infected hundreds of millions of people worldwide.

“We likely know only a small fraction of the viruses infecting wild or even domesticated animals,” the authors of the study state.

There are other human induced changes that can create conditions for viruses to mutate and spread. They range from social and demographic behaviors such as population growth and intravenous drug use to environmental factors such agricultural practices and deforestation.

Complicating the issue is that scientists still do not completely understand how a virus transfers from wildlife to humans. Normally there are multiple barriers to transmission. Such an event is extremely complex and requires the virus to mutate in multiple ways at exactly the right time.

Sometimes it is just the luck of the draw.

All cells in the human anatomy have something called a “host cell receptor.” It is a protein on the surface of cells that viruses bind to and then invade. When humans share the same receptor with wildlife – bats are commonly cited – there is a risk that a virus poses a threat.

How easily a virus is transmitted is another key factor.

HIV requires direct contact with bodily fluids such as blood or semen. West Nile virus is carried by mosquitoes and enters the human body via puncture wound. But when a virus can be transmitted simply through airborne particles it becomes exponentially more efficient.

Siskiyou practitioner: ‘Prevention is key’

Jeanne Yalon-Owens, chief medical officer with Shasta Cascade Health Centers, said much is still unknown about the coronavirus because it is so new. But she said a virus can live on shared surfaces such as keyboards, door handles and faucets for up to three days. Items in a grocery store are another potential source of contamination such as magazines at the check stand.

“I could spread a virus by coughing, by sneezing, or touching my eyes, mouth and nose and then touching a surface and leaving it behind,” she said “Germs can also spread through raw foods such as salads (or) a rare burger. Or the food could have been prepared by dirty hands.”

Incubation period is another issue. Many people may not know they are sick because they are not yet symptomatic. Or their symptoms can be misdiagnosed. According to multiple reports, more than a dozen hospital workers in Wuhan, China, became infected because a single patient presented with severe abdominal pain and coronavirus was not initially suspected.

That supports the term “super-spreaders” where one person can spread a virus indefinitely. The term “Typhoid Mary” comes from a single individual who allegedly spread the disease throughout New York City in the early 1900s.

Yalon-Owens said coronavirus is not all that different from the common flu. Similar precautions are recommended. Some are common sense such as wiping down the Stairmaster at the gym. Maintaining a healthy immune system and eating well or reducing stress are important factors. Washing hands with soap is preferable to hand sanitizer.

“Illness can hit you at any time. Prevention is the key factor,” she said. Once someone does become sick it is “important to respect the virus.”

“Many people get sicker than others … because they continue to work, eat poorly and stay on their screen until midnight and do not sleep well,” she said. “If people would support their immune system at the very first sign of illness, they would do much better throughout its course.”