Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Flow diagram for measles. The population is divided into four compartments: S, susceptible; E, exposed and infected but not yet infectious; I, infectious; R, recovered and immune. Births enter S at the rate μBS(t), and all individuals have a mortality rate μSD = μED = μID = μRD = m. The case reports, C, count infected individuals with probability ρ. Since diagnosed cases are treated with bed-rest and hence removed, infections are counted upon transition to R.
