Estimation of infection rates in population of organisms using pools of variable size

A method is given for estimating the infection rate in a population of organisms when variably sized sample pools are analyzed, a common situation in practice but not one which can be dealt with by existing methodology. An example is given of estimating the infection rate of yellow fever virus in a mosquito population; there is a suggestion that larvae with a longer developmental period had a higher infection rate. The minimum infection rate (MIR) parameter is shown previously for studies with a constant pool size; the MIR is however an acceptable estimate if the true infection rate is small.