- In a coronavirus update press briefing on Monday, the World Health Organization revealed that the latest data shows that asymptomatic spread of the novel virus is “very rare.”
- WHO emerging diseases and zoonosis unit head Dr. Maria Van Kerkhove believes that we should focus on symptomatic cases, as asymptomatic carriers aren’t likely to transmit the virus.
- This could impact the way that we reopen countries or close them back down going forward.
In the early stages of the coronavirus pandemic, the most frightening aspect of the virus was its seeming ability to be spread by asymptomatic patients. If you could potentially become infected and never show any symptoms, how could it be possible to control the spread of the virus without locking everyone indoors?
Our understanding of the novel coronavirus is evolving on a daily basis, and much of what we thought we knew in March is no longer true today. But, in what might be one of the most significant reversals of the pandemic, the World Health Organization now says that asymptomatic spread of the virus is “very rare.” If this is indeed the case, it could fundamentally change the way we approach the virus and reopening going forward.
“What we really want to be focused on is following the symptomatic cases,” said Dr. Maria Van Kerkhove, the head of the WHO’s emerging diseases and zoonosis unit, at a press briefing on Monday. “If we followed all of the symptomatic cases — because we know that this is a respiratory pathogen, it passes from an individual through infectious droplets — if we actually followed all of the symptomatic cases, isolated those cases, follow the context and quarantined those contexts, we would drastically reduce [the spread].”
She then added, in regards to the threat of asymptomatic individuals: “From the data we have, it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual.”
The reason countries were so quick to shut down, and the explanation for these strict social distancing guidelines, is that health experts told us we could be infected and contagious without ever knowing it. Speaking with the press, Dr. Van Krekhove said that many countries are doing “detailed contact tracing” on asymptomatic cases, and are finding that transmission by those patients is “very rare.” That’s not to say that an asymptomatic carrier can’t transmit the virus, but as more data comes in, the likelihood of that happening appears to be minimal.
It’s worth noting that as part of its COVID-19 Pandemic Planning Scenarios, which are meant to help modelers and public health officials prepare community mitigation efforts, the CDC shows that the infectiousness of asymptomatic individuals relative to symptomatic individuals is estimated to be anywhere between 50% and 100%.
UPDATE | 6/9 at 10:06 a.m. ET: The WHO has backtracked on much of what it said yesterday: