Widal test

Widal test

Principle: It is an agglutination test which detects the presence of antibodies against salmonella in the blood flow flowing typhoid and parathyphoid fever.

Types:Its is antibodies detected uncle titer in healthy population:

  1. TO-1:80(Somatic antibody of S.typhi)
  2. TH-1:80(Flagellar antibody of S.typhi)
  3. AH-1:40(Flagellar antibody of S.para typhi A)
  4. BH-1:40(Flagellar antibody of S.para typhi B)


  1. ‘O’antibody is Ig M.Which increase in recent infection and short lasting and ‘H’antibody is Ig type which is long lasting.
  2. Antibodies begin to appear in serum after 10 days.
  3. Single titer is not diagnostic,rising titer is significat(rising titer means ther is increase in titer between two samples at 4-5 days interval)
  4. Fold rise of normal titer is also significant.
  5. Local titer various froms region to region.
  6. Anamenstic reaction due to cross reaction their transient rise of ‘H’antibody titer.
  7. Titer in vaccinated persons depends on duration.
  8. Carrier may be positive in health carries.

Leave a Reply

Need help? e-Mail us here! Chat With Us Now!

← Prev Step

Thanks for contacting us. We'll get back to you as soon as we can.

Please provide a valid name, email, and question.

Powered by LivelyChat
Powered by LivelyChat Delete History