Bounds on R for different probabilities of human transmission, θ.

Current estimates of R (i.e. highest probability R – ML R; and posterior mean R) for human H5N1 avian influenza, obtained from new case time series for Vietnam and Indonesia. “R min” and “R max” denote the lower and upper bounds of the 95% credible intervals, respectively. θ is the probability of human-to-human transmission (see Methods). Analysis of reported cases from Thailand, China, and Turkey lead to similar or lower R estimates, but display wider bounds due to smaller case numbers.