Widal Test

About The Test

The Widal Test is a serological test used to help diagnose typhoid fever (and paratyphoid fever), which are caused by Salmonella enterica serotypes:

• Salmonella Typhi (causes typhoid)
• Salmonella Paratyphi A, B, and C (cause paratyphoid)

The test detects antibodies (agglutinins) in the patient's blood against the O (somatic) and H (flagellar) antigens of Salmonella.

Why Consider this test ?

If you are experiencing symptoms such as:

• Persistent high fever
• Abdominal pain
• Constipation or diarrhea
• Headache
• Loss of appetite
• Weakness and fatigue
• Sometimes a rash (rose spots) on the abdomen

Who should consider this test ?

1.    Patients Who Have Had Fever for More Than 5 Days

2.      Individuals Being Monitored for Rising Antibody Titers

People Living in or Returning From Typhoid-Endemic Regions

Typhoid is more common in:

• South Asia (India, Pakistan, Bangladesh)
• Southeast Asia
• Sub-Saharan Africa
• Parts of Latin America

More About this test :

The test detects two main types of antibodies:

Antigen Tested	Antibody Detected	Indicates
O antigen (somatic)	Anti-O antibody	Active infection (early)
H antigen (flagellar)	Anti-H antibody	Past infection or immunization
AH antigen	Anti-Paratyphi A antibody	Paratyphoid A