Widal test is a serological test, more appropriately an indirect agglutination test used for the diagnosis of Typhoid fever caused by the bacteria Salmonella typhi. It is used for the detection of antibodies that are produced...
What is the Widal test?
Widal test is a serological test, more appropriately an indirect agglutination test used for the diagnosis of Typhoid fever caused by the bacteria Salmonella typhi. It is used for the detection of antibodies that are produced as a response to salmonella infection by your body. The widal test was invented by Georges Fernand Widal and is named after him.
Typhoid fever, also known as enteric fever or undulant fever is a serious infection and can be life-threatening. It is endemic in many regions especially developing countries like India, Africa and south-east Asia. Humans are the host and carrier of salmonella typhi. It is usually transmitted from one person to another through food and water contaminated with salmonella. Upon ingestion, the bacteria multiply rapidly, enter circulation and spread through the bloodstream. The incubation period of salmonella typhi ranges between 6-30 days after which the signs and symptoms of typhoid fever appears clinically.
What are the uses of Widal test?
Widal test is used for the diagnosis of typhoid fever. It is indicated in the following situations:
- Typhoid fever
- To differentiate recent typhoid infection from past infections.
- H/o typhoid infection
- To evaluate cases of high fever
- Food poisoning
- Traveler’s diarrhea
- Evaluation of patients with the following symptoms and signs:
- Anorexia
- Fever with chills
- Body ache
- Abdominal pain
- Nausea and vomiting
- Diarrhea
- Constipation
- Rose spots: faint pink spots usually on the trunk region
- Headache
- Cough
- Weakness
- Fatigue
- In severe cases confusion and agitation
What are the complications of typhoid fever?
Severe complications of typhoid fever usually occur in patients with >2 weeks of illness or those who have either not received treatment or received improper treatment and accounts for approx. 10% cases. Case fatality rate of enteric fever ranges between 1-4% and is higher in untreated patients and children <4 years. Complications may include the following:
- Sudden fall in body temperature
- Shock
- Intestinal bleeding
- Intestinal perforation
- Blood in stools
- Pneumonia
- Cholecystitis
- Myocarditis
- Urinary retention
- Osteomyelitis
- Nephritis
- Thrombophlebitis
- Even psychosis.
What samples are required for Widal test?
Widal test is used for the evaluation of antibodies titer against the somatic antigen (O antigen) and the flagellar antigen (H antigen) of salmonella typhi present in blood/serum.
How do I prepare for Widal test?
Widal test doesn’t require any special preparation. However, these points should be kept in mind if you need a Widal test:
- Book an appointment: Fix your appointment in a diagnostic lab to avoid waiting on the day of the test.
- Food and medications: You can take your daily meals and medications unless otherwise specified.
- Fasting: Widal test can be performed on random blood sample. Fasting is not required for this test.
What is the procedure for Widal test?
The procedure of widal test includes the following steps:
- First a torniquet will be tied around your arm.
- Then a cotton soaked with 70% alcohol is used to disinfect the injection site before needle insertion.
- Then a small needle will be inserted in your vein and required amount of blood is withdrawn from it and collected in a test tube.
- Needle is removed and an adhesive sticker is placed on the puncture site to prevent it from infections.
- Sample collected is sent to a pathological lab for further processing and testing.
What are the methods of Widal test?
Widal test can be performed by two methods and rising titers of antibodies with time by either method points towards the diagnosis of typhoid fever.
- Slide widal test: Steps involved in the slide agglutination test includes the following:
- Blood sample is centrifuged to obtain serum.
- On a glass slide, a drop of serum is placed and a solution containing salmonella antigens is added to the slide.
- Using a glass rod the contents of the slide are mixed thoroughly.
- After 4-5 minutes agglutination occurs due to reaction between antibodies present in the serum sample and antigens in the solution.
- Now slide is examined under microscope to check for agglutination.
- If clumping is present then the test is considered positive.
- Tube agglutination test: Steps involved in the tube agglutination test includes the following:
- Collected blood sample is centrifuged first to separate the serum.
- Around 4 test tubes labelled with patient’s name and date is taken and antigen solution with serial dilution from 1:40 to 1:320 is added to each test tube.
- Now, patients’ serum in fixed proportion is added to each of the test tubes and mixed thoroughly.
- Finally, test tubes are incubated at 37 degrees Celsius for 24 hours.
- After 24 hours, tubes will be examined for agglutination. Presence of clumping demonstrate a positive result.
How to check Widal test report?
Widal test results need careful evaluation and interpretation taking into account for various considerations such as Typhoid vaccination, past history of typhoid fever and level of antibodies in endemic regions of world. Reports can be illustrated as given below:
|
Description |
Antibody titer |
Interpretation of result |
|
O antigen- also known as the somatic antigen. |
>1:160 |
Acute infection |
|
H antigen- also known as the flagellar antigen. |
>1:160 |
*Recovery stage or *Remote/past infection or *Immunized state |
|
Vi antigen- Vi stands for virulence and is capsular antigen. |
Positive |
Carrier state |
Normal range for Widal test?
When the titers for O (Somatic) and H (Flagellar) antigens is <1:160, the result is considered negative and or within normal limits. However, a high titer may also be detected due to infection in past or post typhoid vaccination.
What is the risk/side effects of Widal test?
Widal test is a safe tool for detection of typhoid fever or ruling out enteric fever with usually no side effects. However, some individuals may experience some side effects including:
- Pain at injection site.
- Hematoma due to multiple punctures to locate vein in those where veins are not easily assessable.
- Bleeding at puncture site, especially patients having bleeding or clotting disorders or those on anticoagulant therapy.
What are the other tests used for the diagnosis of typhoid fever?
Typhoid fever or enteric fever can be diagnosed with the help of following tests:
- Widal test
- IgM antibody test
- Typhidot
- Blood culture
- Urine culture
- Stool culture
- Bone marrow examination.
When do I get Widal test report?
Reports may be available on the same day or the next day.
Cost of Widal test in Delhi?
Price of Widal test depends upon many factors such as with city and locality and method of widal test. Different diagnostic labs charges according to the quality of machines they have and various offers that they are providing to their customers.
Ganesh Diagnostic and Imaging centre (GDIC), Rohini also known as GDIC is currently offering 50% discounts on various tests including Widal test. Our centers are NABH and NABL accredited and equipped with modern, highly expensive machines with latest cutting-edge technologies and highly skilled Radiologists and Pathologists.We follow strict aseptic conditions to prevent transmission of infections.
Prices of various test used for the diagnosis of Typhoid fever at Ganesh Lab (GDIC) are as following:
Typhidot IgM and IgG, Rapid Card
To avail free online consultation with Pathologist. Click here!
To know more about our services. Click here!
Best diagnostic centre for Widal test in Delhi?
Ganesh Diagnostic and Imaging center (GDIC) is the best diagnostic center for Widal test in Rohini, North-East Delhi.
We have many branches in different locations of Delhi including Hari Nagar, Yamuna Vihar, Nangloi, Derawal Nagar and Mangol puri. Ganesh Diagnostic and Imaging center is now considered one of the most popular and affordable Diagnostic centers in Delhi.
We provide high standard quality services to our patients. Our labs are NABH and NABL certified. Genuine reporting and Patient satisfaction are our top priority. We offer seamless integration between diagnosis and treatment planning.
Currently, we are offering 50% discount on Various types of Blood tests.
We are open 24x7 and 365 days. You can also avail free Consultation with our Pathologist regarding any blood or imaging test.
We also offer facilities of online reporting, free home sample collection and free Ambulance services in Delhi, NCR. We are empanelled with various departments and organizations. So, you can get the services at panel rate too.
Our empanellment with different departments and organisations:
- DAK
- ESIC
- CGHS NHA
- ECHS
- NDMC
- DELHI JAL BOARD
- RAILWAYS
- NDMC
- DGEHS
- BSES YAMUNA / RAJDHANI POWER LTD
- TATA POWER LTD
- SANJAY GANDHI HOSPITAL
- BABA SAHEB AMBEDKAR HOSPITAL
- BJRM HOSPITAL
- BHAGWAN MAHAVIR GOVERNMENT HOSPITAL
To know details about our empanellment with different organisations. CLICK HERE!
For more details visit your nearest Ganesh Diagnostic and Imaging center (GDIC) today or call us now!
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