Advisers to the Centers for Disease Control and Prevention are concerned about a lack of data from China about the Wuhan coronavirus.
They say the dearth of information is curtailing international efforts to quell the outbreak.
Advisers commended the Chinese researchers for mapping the virus's genome in just a few weeks.
However, they said there's a glaring lack of basic epidemiological evidence about who's getting infected with the virus and how it's spreading.
This is Epi 101.