A World Health Organization Official has clarified her comments on the coronavirus after saying it was “very rare” for people who were asymptomatic to pass on the virus.
But Dr Maria Van Kerkhove, the WHO’s technical lead for Covid-19, told a press briefing on Monday that data from countries which had carried out detailed tracking and following up of contacts showed there was little evidence of true asymptomatic spread.
“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 onwards – it’s very rare,” she said.
However, after experts called her comments into question she told a live question and answer session the following day that her comments on asymptomatic spread were based on small number of studies of contact tracing and cluster investigations. She added that modelling estimates suggest that up to 40 per cent of transmission was by asymptomatic carriers.
“I was referring to some detailed investigations – cluster investigations, case contact tracing – where we had reports from member states saying that it is very rare – and I use the phrase very rare – that we find secondary transmission from asymptomatic cases,” Dr Van Kerkhove said on Tuesday.
However, the fact that contact tracing shows little evidence of asymptomatic spread may go some way to reassuring head teachers who are reluctant to reopen schools over fears that children may be asymptomatic carriers of coronavirus and could pass it on to teaching staff.