Expert questions effectiveness of coronavirus airport screening
Medical staff at airports trying to screen for carriers of the newly discovered coronavirus face a major problem. Its exact impact inside a human is still not known.
Related: No screening for new Sars-like virus at UK airports – yet
“At an airport, the thing you are screening for is temperature,” said Dr Jeremy Farrar, director of the Wellcome Trust. “A camera is used to identify if a person has a fever. If so, they may be infectious.”
But in many conditions – such as influenza – a person often becomes infectious before their temperature starts to rise and they develop other symptoms. As a result, screening for such conditions at airports may miss infectious individuals and that means the technique has limited value.
“You use up a lot of resources for only marginal benefit,” said Farrar. “The point is that we do not know yet if a person who has been infected with this new virus will have a high temperature when they are at their most infectious and ready to pass on the virus. They may have. It is equally possible they may not have. We urgently need to know that information. The answer will tell us whether screening at airports has any value or not.”
On the other hand, screening at airports is a highly visible sign that somebody is doing something about a disease outbreak, Farrar acknowledged. “It can be reassuring. It suggests authorities are doing their best to contain an outbreak. So, to that extent, screening has some value. On balance, I think it is perfectly reasonable the UK has decided at this stage not to screen at airports.”
As to the source of the new disease, Farrar said he thought bats would probably prove to be the final vector that brought the virus out of the animal kingdom to infect humans. “Bats are sold in many markets across Asia as a delicacy and food, and they also have this ability to host viruses and not get sick. They are a remarkable source of viruses that can jump into humans, as we have seen with Sars, Ebola and Nipah fever in recent years. There are huge populations of them and they come into close proximity with humans.”
