Fig. 1.

Schematic representation of disease states in a model of a measles outbreak in Cox’s Bazar. Individuals are either susceptible to measles (S), infectious with measles (I), or recovered from and immune to measles infection (R), either due natural immunity from infection or prior vaccination. β represents the transmission coefficient, γ is the recovery rate, and μ is the birth and death rate. The model starts with one infected (and infectious) measles case (i.e., I (0) = 1) The number of recovered individuals at time = 0 was calculated as R(0) = N − S (0) − I (0). The model tracks the number of individuals that move between the compartments each day and is run for one year using the ordinary differential equations (1)–(3).