<prompt> Which of the following can cause an increase in the prevalence of the disease -Immigration of healthy personsIncreased cure rate of diseaseLonger duration of illnessDecrease in population  <response>: Derived Factors that increase Prevalence Prevalence increases with addition of diseased people immigrationPrevalence increases with subtraction of healthy people emigrationPrevalence increases with prolongation of life in chronic diseasesPrevalence increases with decreased death rate amongst diseasedDerived Factors that decrease Prevalence Prevalence decreases with addition of healthy people immigrationPrevalence decreases with subtraction of diseased people emigrationPrevalence decreases with increased cure ratesPrevalence decreases with increased death ratesPrevalence decreases with preventive programs such as immunization which prevent new cases from occurring. 