The spread of COVID-19 by someone who is not showing symptoms of the virus ‘appears to be rare’, the World Health Organization (WHO) said Monday, casting doubt on concerns made by some researchers that the disease could be difficult to contain due to asymptomatic infections.
Preliminary research into the coronavirus outbreak indicated that the deadly disease could be spread through person-to-person contact even if the carrier had no symptoms.
While WHO says asymptomatic spread can still occur, scientists believe it’s no longer the main way the virus is being transmitted.
‘From the data we have, it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual,’ said Maria Van Kerkhove, the WHO’s technical lead for COVID-19, during a press briefing Monday.
‘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 is very rare – and much of that is not published in the literature,’ she said
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‘From the data we have, it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual,’ said Maria Van Kerkhove, the WHO’s technical lead for COVID-19, during a press briefing Monday
As a result, Kerkhove advised that government responses should prioritize detecting and isolating infected people with symptoms, and tracking anyone who might have come into contact with them.
However Kerkhove conceded the findings are not yet conclusive.
‘We are constantly looking at this data, and we’re trying to get more information from countries to truly answer this question,’ she said. ‘It still appears to be rare that an asymptomatic individual actually transmits onward.’
If asymptomatic spread proves to not be the main catalyst of coronavirus transmission, the implications could be huge.
In April, the US Centers for Disease Control and Prevention cited the ‘potential for presymptomatic transmission’ as the main reason behind the need for social distancing.
‘These findings also suggest that to control the pandemic, it might not be enough for only persons with symptoms to limit their contact with others because persons without symptoms might transmit infection,’ the CDC reported.
But if WHO’s latest revelation is proven true, the ways in which the virus is currently screened and contained could change considerably.
‘What we really want to be focused on is following the symptomatic cases,’ Van Kerkhove said.
‘If we actually followed all of the symptomatic cases, isolated those cases, followed the contacts and quarantined those contacts, we would drastically reduce [the outbreak].’
If WHO’s latest revelation is proven true, the ways in which the virus is currently screened and contained could change considerably
In April, the US Centers for Disease Control and Prevention cited the ‘potential for presymptomatic transmission’ as the main reason behind the need for social distancing
However, Ashish Jha, director of the Harvard Global Health Institute, expressed some scepticism over Kerkhove’s claims.
Jha believes asymptomatic transmission is, in fact, an important source of spread and that some modeling shows as much as 40 to 60 percent of transmission comes from people without symptoms.
Jha said it’s possible the WHO is making a distinction between asymptomatic spread and presymptomatic spread, when someone eventually develops symptoms but spreads the virus before they do.
Globally, the coronavirus has killed over 400,000 people. In the U.S. infections are approaching two million, with more than 110,000 deaths.
The virus continued to ravage the likes of Brazil, which over the weekend stopped reporting a daily updated death toll after it surpassed 34,000 fatalities, the third-highest in the world, behind the United States and Britain.
‘More than six months into this pandemic, this is not the time for any country to take its foot off the pedal,’ the head of the WHO, Tedros Adhanom Ghebreyesus said during the same news conference. ‘This is the time for countries to continue to work hard.’