Transmission Dynamics and Control of Infectious Disease Agents

Abstract

The concept of an infection's (or parasite's) basic reproductive rate, R0, is central to an understanding of the population biology of infectious disease agents. This parameter R0, measures the ability of an infection (or parasite) to give rise to secondary cases (or second generation parasites), and its value is determined by a variety of factors specific to the biology of the disease agent and that of its host. The condition, R0 = 1, defines a transmission threshold below which a disease is unable to maintain itself within the human community. The value of R0 can be estimated from horizontal or longitudinal epidemiological studies of the prevalence and intensity of infection in various age classes of the population. Measurement of this parameter provides a means of estimating the proportion of the community that must be immunized, or receive chemotherapeutic treatment, either to eradicate an infection or to reduce its prevalence to a defined level.