The World Health Organization is trying to clarify some confusion over the spread of the coronavirus by infected by asymptomatic people.
In a media briefing in Geneva on Monday (June 8), Maria Van Kerkhove, WHO’s technical lead for coronavirus response and head of its emerging diseases and zoonoses unit, said that “it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual.”
She also went on to explain that, in many cases, those who appear to be asymptomatic actually have a mild case of the disease.
“When we actually go back and we say how many of them were truly asymptomatic, we find out that many have really mild disease,” she said.
“They’re not quote-unquote Covid symptoms — meaning they may not have developed fever yet, they may not have had a significant cough, or they may not have shortness of breath — but some may have mild disease,” Maria added. “Having said that, we do know that there can be people who are truly asymptomatic.”
On Tuesday (June 9), she clarified her comment on the matter in a live Q&A, saying “this is a major unknown.”
“The majority of transmission that we know about is that people who have symptoms transmit the virus to other people through infectious droplets — but there are a subset of people who don’t develop symptoms, and to truly understand how many people don’t have symptoms, we don’t actually have that answered yet,” Maria said.
“We do know that some people who are asymptomatic, or some people who don’t have symptoms, can transmit the virus on,” she continued. “So what we need to better understand is how many of the people in the population don’t have symptoms and separately how many of those individuals go on to transmit to others.”
She added that the comments she made on Monday were based on some reports that followed a small group of asymptomatic individuals to study the rate of spread of infection with their contacts.
“That’s a very small subset of studies. So I was responding to a question at the press conference. I wasn’t stating a policy of WHO or anything like that,” she said. “Because this is a major unknown, because there are so many unknowns around this, some modeling groups have tried to estimate what is the proportion of asymptomatic people that may transmit.”
The public largely uses the word “asymptomatic” to describe infected individuals who have not shown symptoms of the disease. However, there are also “pre-symptomatic” carriers – infected people who have NOT YET shown symptoms – who can also spread infection.
In the same live Q&A, Dr. Mike Ryan, executive director of the WHO Health Emergencies Program, also says they’re still learning about how the disease spreads.
“Whatever proportion of disease is transmitting from asymptomatic individuals, as Maria said, that is unknown,” Dr. Ryan said.
“I’m absolutely convinced that that is occurring. The question is how much,” he said. “There’s much to be answered on this. There’s much that is unknown.”
According to top infectious diseases expert in the United States, Dr. Anthony Fauci, there’s evidence that about 25%-45% of infected people most likely don’t have symptoms.
“And we know from epidemiological studies they can transmit to someone who is uninfected even when they’re without symptoms,” he told Good Morning America in an interview Wednesday (June 10).
He also shared his concerns about the spread of coronavirus amid the reopening of the states and the ongoing protests happening in cities across the U.S..
“Masks can help, but it’s masks plus physical separation. And when you get congregations like we saw in the demonstrations…that’s taking a risk,” he said, urging the public to practice social distancing.
He also explained how everyone show continue to practice a degree of caution as states continue to lift restrictions.
“When you open, that doesn’t mean that everything is okay and you can just do whatever you want. You still have to practice a degree of caution and carefully go through the process of trying to normalize,” he said. “That means you still should be wearing a mask, you still should be trying as best as possible to have that physical distancing. You still need to wash your hands as often as you possibly can and avoid congregations in large numbers.”
