Infectious disease specialists have called on epidemiologist Maria van Kerkov of the World Health Organization that the transmission of Covid-19 by asymptomatic carriers is “very rare”, warning that the directive will create problems for governments that are trying to block it.
Maria van Kerkhove, a technician in charge of treating coronavirus pandemic at the WHO, said many countries that apply contact tracking have identified asymptomatic cases but have not found that they cause further transmission of the virus. “It’s very rare,” he said.
“I was very surprised by the statement from the World Health Organization,” said Liam Smeeth, a professor of clinical epidemiology at the London School of Hygiene and Tropical Medicine, adding that he had not seen the data on which Maria van Kerkoff’s statement was based.
“It contradicts my findings to date from science, according to which asymptomatic people – who never show symptoms – and pre-symptoms are an important source of infection for others.”
Officials at the World Health Organization were not available today to comment on the matter, while Van Kerkov herself will answer questions on social media within the day.
Liam Smith and other scientists say understanding the risks of infection between people with mild or no symptoms is critical as governments begin to relax the lockdown measures they have taken to control the spread of the epidemic and progressively replace them with trace systems. and isolation.
“This has a serious impact on the tracking/locating/isolating measures introduced in many countries,” said Babak Javid, a consultant for Cambridge University Hospitals.
Some experts say that it is not uncommon for people with coronary heart disease to have no symptoms.
What research shows
Underestimated by a similar study in Germany in May, based on data from 919 people in the Heinzberg region – one of the deadliest death tolls in the country – one in five people infected with the virus showed no symptoms.
But there is little evidence of how these individuals transmit the disease.
The head of the anti-coronation committee in Singapore told Reuters yesterday that there had been cases of transmission of asymptomatic organisms among people living in close contact with other people.
China said last week that 300 Covid-19 asymptomatic carriers in the city of Uhan, the epicentre of the pandemic, had not been found to be contagious.
Keith Neal, a professor of infectious disease epidemiology at the University of Nottingham in Britain, said that while answering the question of how important the role of asymptomatic bodies is in transmitting the disease is unclear, it is certain that people with symptoms are responsible for most of the spread of the disease.
“This reinforces the importance of the directive that any person with any of the symptoms of Covid-19 should seek to have the test performed as soon as possible and isolated until they receive the test results.”