Professor Philip Nolan has outlined why tests for Covid-19 can sometimes fail to detect cases of the virus. He also revealed that a close contact of an infected person has "about a one in 10 chance" of having contracted the disease.
The chair of the National Public Health Emergency Team (NPHET) Irish Epidemiological Modelling Advisory Group said on Twitter that there are two reasons why tests may not detect Covid-19. "First, at any given time, about 30% of infected people are in the latent period, the three to five days after they have been infected, where the virus is multiplying inside their cells and is not yet detectable. "Second, even when they start to shed the virus, a sensitivity of 70% to 90% means the test will fail to detect the