The correct answer is Widal Test.

  Key Points

•  Widal Test:-
  • The Widal test is a blood test used to diagnose typhoid fever.
  • It was developed by Carl Widal in 1896.
  • In the Widal test, the patient's blood is tested for antibodies that are produced against Salmonella typhi, the bacteria that causes typhoid fever. If antibodies are found in the patient's blood, this may be a sign of typhoid fever.
  • The Widal test can be used to diagnose typhoid fever, but it is not always accurate. A negative result does not mean that the patient does not have typhoid fever. In addition, a positive result does not mean that the patient currently has typhoid fever. A positive result may also indicate that the patient has recently recovered from typhoid fever.

  Additional Information

• C-reactive protein (CRP):-
  • The C-reactive protein (CRP) test is a blood test that measures the level of C-reactive protein in your blood.
  • CRP is a protein produced by your liver. The level of CRP in your blood increases when there is inflammation in your body. Inflammation is a natural response to injury or infection.
  • It helps your body heal and protect itself from further damage. However, chronic inflammation can be harmful and lead to health problems such as heart disease, stroke, and cancer.
• Vivax test:-
  • The Vivax test is a rapid diagnostic test (RDT) used to detect Plasmodium vivax, the most common species of malaria outside of Africa.
  • The test works by detecting antigens, which are proteins produced by the malaria parasite, in the patient's blood.