We detected influenza virus RNA in the exhaled breath of 33% of subjects with laboratory-confirmed influenza.  …  In the present study, we measured generation rates of <192 and 1200 influenza virus RNA copies per hour for subjects with detectable influenza virus RNA in their breath. … This implies that the quantum generation rate we measured in our subjects is 10-fold higher than the Rudnick and Milton estimate for a “superspreader”.1

—  Fabian P, McDevitt JJ, DeHaan WH, Fung ROP, Cowling BJ, et al. (2008) Influenza Virus in Human Exhaled Breath: An Observational Study. PLoS ONE 3(7): e2691. doi:10.1371/journal.pone.0002691

  1. However, … the generation rate of infectious viruses may be as little as 1/300th of the total number determined by PCR and the resulting estimates of quantum generation rate (<0.64 to 4 quanta/h) from our data are lower than those estimated for a superspreader by Rudnick and Milton.”[]