RIO DE JANEIRO, BRAZIL - Studies have shown that people who have contracted the novel coronavirus are more infectious when they present the initial symptoms, said Maria van Kerkhove, epidemiologist and World Health Organization (WHO) technical head for the pandemic, in a statement released on Tuesday.
She said a subgroup of people do not develop symptoms, but may still infect others, and up to 40 percent of transmissions can occur through asymptomatic cases.
This statement was made . . .