Readers still have questions about COVID-19

Many of you continue to have questions about the novel coronavirus.

“If a sneeze can spread the virus, can exhaling also spread the virus?” a reader asked. “So many times I see people with their mask under their nose and want to say something, but do not because I do not want to get into a fight.”

It's important to remember that we're still in the earliest stages of learning about the novel coronavirus. Emerging research suggests that, in addition to respiratory droplets from a cough or a sneeze, the virus may also be present in the microdroplets expelled during breathing and speech. What isn't yet clear is whether or not these are a major source of infection. We will keep an eye on that research and update any new findings.

When it comes to wearing a mask, you're correct on two points. First, the mask should indeed cover both the nose and the mouth. It should also have a snug fit around the perimeter. And we think you're wise not to comment on how someone else wears his or her mask. Unfortunately, this practice, which we engage in to protect each other, has become a hot-button issue. Better to move at least 6 feet away from that individual and go about your day.

What about burps?

And speaking of transmission: “Why aren't belching and expectorating mentioned as vehicles for spreading the coronavirus?” a reader asked. “If I can smell the belched air, surely it's possible for the virus to be suspended in it.” The act of spitting or emitting a large and sustained belch can send respiratory droplets into the air. Although it's possible that these can spread the virus, they are not known to be a major means of transmission.

Is reinfection possible?

A reader who recently survived COVID-19 wrote to ask about the likelihood of becoming infected again. “I contracted COVID-19 on July 1, became ill and tested negative on July 21,” he wrote. “My symptoms were coughing, muscle aches and fatigue. Pneumonia ensued for two weeks. I then tested positive for antibodies on July 23. How concerned should I be about contracting it again?”

Unfortunately, the answer isn't clear yet. Researchers in Hong Kong recently identified what appears to be the first known case of reinfection 4½ months after a patient's initial illness. This reinfection, with a slightly different strain of the virus, occurred when the young man traveled to Spain. Genomic testing revealed differences in the two variants of the virus, which researchers say proves this is indeed a reinfection rather than prolonged viral shedding. The young man had no symptoms, and researchers believe existing antibodies helped his immune system fight off the second infection. Still, the wisest course is to continue practicing all precautions to protect yourself and those around you.

• Dr. Eve Glazier is an internist and associate professor of medicine at UCLA Health. Dr. Elizabeth Ko is an internist and assistant professor of medicine at UCLA Health. Send your questions to askthedoctors@mednet.ucla.edu.