Prevalence/Prevalans?
1. If 20 cows in a herd of 200 cows were lame on a particular day, what would prevalence be?
2. Belirli bir günde yapılan araştırmada, 300 sığırlık bir popülasyonun 30’nda tüberküloz saptanırsa, prevalansı kaç olur?
■ Prevalance= number of individuals having a disease at a particular point in time
number of individuals in the population at risk at that point in time
1. 20/200= 0.1 2. 30/300= 0.1
Cumulative incidence/Kümülatif insidens?
1. If 20 animals in a cattery develop feline viral rhinotracheitis during a week, and there are 100 healthy cats in the cattery at the beginning of the week, then, the CI for the week?
2. Bir köpek çiftliğindeki 10 köpekte 1 hafta içinde pnömoni gelişirse ve bu çiftlikte hasta başında toplam 50 köpek varsa, o hafta için
kümülatif insidens?
■ CI = number of individuals that become diseased during a particular period
number of healthy individuals in the population at the beginning of that period
1. 20/100= 0.2 2. 20/50= 0.4
Morbidity/ Mortality?
1. If there are 200 animals in a flock of sheep and 50 of them have brucellosis, then morbidity?
2. If there are 1000 animals in a flock of sheep and 200 of them die because of enterotoxemia, then mortality?
■ Morbidity= number of diseased animals x 100
number of total animals
■ Mortality= number of deaths x100
number of total animals
1. (50/200)x100= 25%
2. (200/100)x100= 20%
