Endemic (epidemiology)

Every year, there are a few cases of malaria reported in the UK, but these do not lead to sustained transmission in the population due to the lack of a suitable vector (mosquitoes of the genus Anopheles).

Assuming a completely susceptible population, that means that the basic reproduction number (R0) of the infection must equal one.

This takes account of the probability of each individual to whom the disease may be transmitted being susceptible to it, effectively discounting the immune sector of the population.

An infection that starts as an epidemic will eventually either die out (with the possibility of it resurging in a theoretically predictable cyclical manner) or reach the endemic steady state, depending on a number of factors, including the virulence of the disease and its mode of transmission.

[5] If a disease is in an endemic steady state in a population, the relation above allows the basic reproduction number (R0) of a particular infection to be estimated.

Human alphaherpesvirus 3 virion − a herpesvirus known to infect humans. It causes chickenpox (varicella) , a disease most commonly affecting children, teens, and young adults, and shingles (herpes zoster) in adults.