<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi Doc, I was having continuous fever for the last 2 weeks and when got the blood test done, it was S-Typhi positive with the dilution rate of 1:160. am on medication since last 10 days... Wanted to know the normal and critical dilution rate just for my own satisfaction  <response>: Hi as per the history provided by you with fever last 2 weeks and S.type positive for 1:160 it seems that the cause of your fever is infection with Salmonella type. Now the value in your history 1:160 dilution rate is the title of the antibody produced by your body in trying to protect you from the organism S type in your case. Now the title dilution rate of 1:160 is significant and suggestive of S type infection. The normal title dilution rate is below 1:80 in endemic regions of India that is value below this title doesnt signify infection and this much value we get in normal people also. 