However, a team from the London School of Hygiene and Tropical Medicine estimated that 80 percent of infections are caused by only 10 percent of carriers.
End quote
That may number wise,correlate somewhat to the psychopath descriptive trait.
"Psychopathy is a condition characterized by the absence of empathy and the blunting of other affective states. Callousness, detachment and a lack of empathy enable psychopaths to be highly manipulative."