The World Health Organization (WHO) on Tuesday, June 9, issued a clarification on their statement that coronavirus transmission from asymptomatic carriers was "very rare."
It is still "unclear how readily the novel coronavirus is spread by people who don't develop symptoms," WHO's Maria Van Kerkhove says a day after she said such transmissions are "very rare." https://t.co/NsxD5XD94E pic.twitter.com/TYlL43dmPo— Bloomberg (@business) June 10, 2020
Maria Van Kerkhove, WHO's technical lead for coronavirus response had said earlier that, "We have a number of reports from countries who are doing very detailed contact tracing. They're following asymptomatic cases, they're following contacts and they're not finding secondary transmission onward. It's very rare."
Transmission of the coronavirus by asymptomatic people is "very rare," says the WHO's Maria Van Kerkhove, contradicting a widely held belief among health officials and researchers— Bloomberg (@business) June 9, 2020
More: https://t.co/IWulYT7aZ3 pic.twitter.com/RSonv1slKO
The WHO official had told that it seemed to be rare that an asymptomatic person would actually transmit the infection onward to a secondary individual, following a social media uproar she clarified that while 6-41 per cent COVID infected people may not show symptoms, many might transmit the disease.
However, Kerkhove clarified on her statement saying: "What I was referring to yesterday in the press conference were very few studies - some two or three studies that had been published that actually try to follow asymptomatic cases, so people who are infected, over time, and then look at all of their contacts and see how many additional people were infected."
She explained that she earlier referred to a very "small subset of studies" while responding to a question at the press conference. She asserted that she was not stating a policy of the WHO.
"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," she added.
1/2@WHO recently published a summary of transmission of #COVID19, incl. symptomatic, pre-symptomatic and asymptomatic transmission— Maria Van Kerkhove (@mvankerkhove) June 8, 2020
See page 2 of👇https://t.co/2OJ2pLT5Iu
In this summary, we state: "Comprehensive studies...
2/2 ... on transmission from asymptomatic individuals are difficult to conduct, but the available evidence from contact tracing reported by Member States suggests that asymptomatically-infected individuals are much less likely to transmit the virus than those who develop symptoms— Maria Van Kerkhove (@mvankerkhove) June 8, 2020
additional points:— Maria Van Kerkhove (@mvankerkhove) June 8, 2020
In these data, it is impt to breakdown truly asymptomatic vs pre-symptomatic vs mildly symptomatic
also to note that the % reported or estimated to be "asymptomatic" is not the same as the % that are asymptomatic that actually transmit