Here are the facts you probably haven’t heard…

Since the new coronavirus began hopscotching from Wuhan, China, to other countries—including the US—public health officials have scrambled to keep up with the ­potential threat that it poses to millions of people around the world.

This virus, called the “novel coronavirus,” or COVID-19, has proven to be a formidable opponent. Each day, the number of people sickened by it climbs, along with the death toll (estimated at more than 2,000 at press time).

What does this mean for you and your family? And do you know all you need to know to stay safe from this and other life-threatening viruses? To give you the full story on the dangers posed by this virus, we spoke to Miryam Wahrman, PhD, a microbiologist and expert on how to reduce the risk from communicable diseases.

How could a new virus such as this spread so quickly? COVID-19 isn’t entirely new. It is the latest member of a family of viruses called human coronaviruses that were first discovered in the 1960s. Seven types can infect humans. Four types can cause common colds.

For the most part, coronaviruses typically infect animals. The genetic material of the viruses can evolve, though, and infect humans and then spread among humans. For example, Severe Acute ­Respiratory Syndrome (SARS) was caused by a coronavirus that jumped from animals to humans in 2002. With SARS and COVID-19, this is believed to have happened in one of China’s live-animal markets.

Much like what is occurring today with COVID-19, SARS spread outside of China via air travelers who were infected. The SARS virus eventually sickened about 8,000 people and killed nearly 800 who succumbed to pneumonia (mostly in mainland ­China). Largely because of effective public health measures, only eight people in this country tested positive for a SARS infection.

A coronavirus that was first identified in Saudi Arabia in 2012 originated in camels and then jumped to humans. This virus led to an illness called Middle East Respiratory Syndrome (MERS). MERS also caused pneumonia and was even deadlier than SARS, killing three out of every 10 people who were infected. Isolated ­cases continued after the initial outbreak, with about 860 deaths being reported. Only two people in the US ever tested positive for MERS.

How contagious is COVID-19? It will take more time to know exactly. In ­China, health authorities know that it can spread from person to person because individuals who have had no contact with animal markets have become infected. A novel virus can be more hazardous than one that has been around for a while because people have not developed immunity, making them more susceptible to the disease. Newborns and infants could be at high risk for serious infections from COVID-19 because mothers (who are not immune) can’t pass on antibodies through the placenta during pregnancy or through mother’s milk after birth.

Assuming that COVID-19 is found to be similar to SARS, for example, it may require “close contact” to spread. Examples of this include kissing or hugging…sharing eating utensils or drinking vessels…touching someone ­directly…and talking to someone within three feet (you can breathe in droplets that a sick person coughs or sneezes or simply exhales near you).

Coronaviruses also can be transmitted by touching an infected surface. Say an infected person sneezes or coughs into his/her hand and then touches an ­elevator button or doorknob. If you touch that spot and then touch your mouth, nose or eyes, you can become infected. The SARS and MERS coronaviruses, which may be similar to COVID-19, were found to persist on surfaces, such as metal, glass or plastic, for up to nine days, according to an analysis of 22 studies published in The Journal of Hospital Infection.

Note: Scientists in China have detected “virus genetic material” in stool samples of patients, suggesting a possible fecal-oral transmission route for COVID-19.

Is COVID-19 worse than the flu? Like the flu, it causes coughing, fever, fatigue and, in rare cases, diarrhea. In China, most people seem to get a mild infection from COVID-19 and recover at home with standard self-care, such as over-the-counter medication, fluids and rest.

However, some people—for reasons we don’t yet understand—get much sicker and may die (reportedly, COVID-19 may be up to 20 times more lethal than the flu). When the illness progresses, it does so relatively quickly, leading to pneumonia. Patients who have pneumonia-like symptoms should immediately seek medical assistance so their condition does not become life-threatening.

Scientists still are investigating the profiles of those who have become ill from COVID-19. In general, people who are very old or very young or who have compromised immune systems typically are at higher risk for complications from infectious diseases.

But we must keep COVID-19 in perspective. It is believed to have killed more than 2,000 people (at press time), but during a typical flu season in the US, 10 million to 45 million people are sickened, with as many as 61,000 deaths, according to the CDC.

What’s the best way to avoid the new coronavirus? There is no vaccine, so proper hand-washing is your best first line of defense. This advice is so simple that some people tend to tune it out or become careless. But washing your hands with water and plain soap (not antibacterial soap—it may contribute to antibiotic resistance) is key.

Important: Be sure to rub your hands together vigorously, lathering and scrubbing the palms and backs of the hands and between the fingers for a full 20 to 30 seconds. In public ­restrooms, dry your hands with a ­paper towel, if available, as warm air or jet dryers can spread germs.

If you can’t wash your hands, use ­alcohol-based hand sanitizer. Most people use too little hand sanitizer, so be sure to use a large enough quantity to cover all surfaces—palms, backs of hands, fingers and in between fingers. Then, do not wipe it off…let it air dry.

Another option is to wear a mask. This is most effective when the sick person dons the mask, but that’s not always possible. A caretaker should wear gloves and a surgical mask when tending to ­someone with an infectious disease. You can buy surgical-style masks in the drugstore. To get the most protection from this type of mask, be sure that your mouth, nose and chin are covered, and mold the metallic strip to your nose. Change the mask each day, and wash your hands after disposing of it.

When using public transportation, where there is a risk that infected people may be present, wearing a mask may make sense. At least carry one when flying in case you are seated next to someone who appears sick. Wash your hands before eating or touching your eyes, nose or mouth, and carry hand sanitizer for when soap and water are not available. If you know someone who has been to an affected area, be cautious about contact with him until you can be confident that he is disease-free and past the presumptive incubation period.

For updates on COVID-19, check the CDC site.