As many businesses and communities take steps to prevent the spread of COVID-19, scientists are working as quickly as possible to learn all they can about the disease and its cause, the novel coronavirus. New studies are being published almost daily, including a recent study that suggests the virus may spread in a different way than originally thought by authorities.

Previously, scientists believed that people infected with the new coronavirus were most infectious when their symptoms (open in new tab) were pronounced. The virus is transmitted from person to person through particles, says Dr. Richard Kuhn, a professor of biological sciences at Purdue University. Particles are released when a person touches a surface after coughing, sneezing, or wiping his or her nose or mouth.

Thus, if someone sneezes, coughs, or has a fever, or otherwise looks ill, that person would be considered likely to transmit the illness to others. Current CDC guidelines clearly state that "people are considered to be most infectious when they are most symptomatic," and that "infection can spread before symptoms appear. (It also states, however, that "COVID-19 is a new disease and we do not yet know how it will spread, how severe it will be, or how likely it is to spread in the United States.")

A study published in MedRxiv on outbreaks in Tianjin, China and Singapore in January and February found that a significant number of infections were attributed to people who had not yet developed symptoms. (It is believed that 48% of the COVID-19 infections in Singapore that were studied came from people who had not yet developed symptoms. In Tianjin, China, the figure was 62%. [In a letter (opens in new tab) recently published in the New England Journal of Medicine (opens in new tab), the researchers report that two people recently returned to Germany from Wuhan, China, who appeared to be asymptomatic, had pharyngeal swab samples that were positive for COVID-19 (opens in new tab) The researchers point to another situation in which two people recently returned to Germany from Wuhan, China, who appeared to be asymptomatic, were positive for COVID-19 (opens in new tab). The researchers wrote in their letter, "We found that shedding of potentially infectious viruses can occur even in persons with no fever and no or only minor signs of infection."

Bill Gates also wrote a letter to the New England Journal of Medicine (opens in new tab) in February expressing similar concerns.

"COVID-19 infects very efficiently; COVID-19 infects very efficiently," he wrote. 'There is also strong evidence that it can be transmitted from people with mild illnesses, or even before symptoms develop.' This means that COVID-19 is much more difficult to contain than Middle East Respiratory Syndrome or Severe Acute Respiratory Syndrome (SARS), which were transmitted only by symptomatic people and were less efficient in transmission.

Although this new study contradicts the original thinking about this virus, Kuhn does not find this information so surprising. Many viral infections start before someone gets sick and starts producing new viruses," he says. It gives no hint that someone is infected and causes real problems." [15] [16] The new coronavirus is not the first disease that can infect someone who appears to be perfectly healthy. For example, one can have the flu and still pass it on to others without a cough or fever. [17] [18] "Even if you are perfectly healthy," he says, "if you have a virus and it is actively multiplying, just one cough or sneeze, or you wipe your nose and touch the counter, can transfer those viral particles. "This seems to be a fairly infectious virus, and it doesn't take very many viral particles to initiate infection. What this means is that this particular type of coronavirus seems to be particularly infectious and can be transmitted via only a small number of viral particles. According to Kuhn, even touching a door handle that has been touched by a person infected with the virus can result in person-to-person transmission.

Our understanding of the new coronavirus may be changing, but what experts have recommended as the best way to protect oneself from infection (opens in new tab) has not. In fact, this new study underscores how important it is to take precautions such as hand washing (opens in new tab) and social distancing (opens in new tab).

According to the CDC, social distancing means avoiding large gatherings and staying about 6 feet away from other people whenever possible; on Sunday, March 15, the CDC issued a new advisory to cancel more than 50 events across the U.S. for the next eight weeks.

Social distancing can help slow the speed at which the virus spreads and limit the likelihood of infecting at-risk populations. You may be a healthy adult and have no symptoms, but you are at risk of transmitting the new coronavirus to others whose immune systems cannot handle the virus.

Kuhn also points out that working from home and staying inside on weekends instead of going out may be disruptive, but it is essential for reducing the spread of the virus. He says that we should continue to take the necessary precautions and follow the CDC's recommendations, especially as scientists continue to do more research on this virus.