question regarding 'infectious doses'

[AliceT]

Hi,

 

i cant seem to find anywhere on the internet a clear answer to a question that i have, i believe (with very little knowledge) the term infectious dose (ID50) is the number of organisms that will cause disease (morbidity) in 50% of test animals (correct??)

 

so my question is what does a low (ID50) indicate about an organism?

 

i hope this question makes sense!

 

thanks,

 

Alice

[CharonY]

Your definition is quite correct and basically you already got the answer there. Think about it for a second. A low ID50 means that a low number of organisms are required to cause the diseases (in 50% of test subjects). So what does it mean if you compare it to a disease with a high ID50?

[AliceT]

Thankyou very much for your response, you have made it clearer for me to understand now. (sorry for the delay in thanking you, i didnt realise anyone had replied)

 

Thanks again!!