New methods were presented to estimate both the individual and household reproduction number during an epidemic. The new method presented for estimating the individual reproduction number relates closely to earlier work [12, 27, 30] , but provides an alternative and possibly simpler solution to the problem of incomplete observations during an unfolding epidemic [29] . It also provides an alternative and perhaps more satisfying solution than the incidence-to-prevalence ratio method [37, 38] to the problem of long generation time distribution infections such as HIV, where epidemiological circumstances can change substantially within the course of a single infection, and thus the case reproduction number represents too much of an average to convey secular changes in behaviour and transmission.