Widal Test Positive Means, Normal Range, and More!
Medically Reviewed By
Dr. Geetanjali Gupta
Written By Sheena Mehta
on Dec 9, 2024
Last Edit Made By Sheena Mehta
on Dec 9, 2024
Did you know that the Widal test exists?
The Widal test helps detect typhoid fever and paratyphoid fever in the body. These conditions are called enteric fever, caused by consuming food or water contaminated with Salmonella bacteria.
Additionally, microorganisms such as Salmonella typhi and Salmonella Paratyphi A, B, and C are responsible for causing this type of fever, which is acute and can be life-threatening. Let's discover it in detail.
What is the Widal test?
The Widal test detects two different types of fever, which are caused by the consumption of contaminated water or food. Hence, it can make you ill. In the Widal test, doctors take a sample of your blood that contains antibodies that will react and agglutinate salmonella antigens.
Georges Ferdinand Widal first conducted the Widal test in 1896; thus, the test was named after him.
Additionally, the test is an advanced way to detect antibodies. Your body makes these antibodies against the salmonella bacteria that cause typhoid fever.
Nevertheless, a stool culture test, a bone marrow test, and other tests are available to detect typhoid infection in the body. However, the Widal test is the most effective method to check for antibodies against Salmonella typhi bacteria.
What are the main symptoms of a person with typhoid fever?
The onset of typhoid symptoms is anywhere from 5 to 14 days after your body comes in contact with S. Typhi. In case of typhoid fever, your body may experience tiredness, high fever, headache, diarrhea, or constipation. Other symptoms include:
- Abdominal pain
- Weight loss
- Red spots
- Blood in the stool
- Chills
- Loss of appetite
- Weakness
- Difficulty concentrating
- Irritation
- Hallucinations
What does the Widal test measure?
The Widal test measures the titers of antibodies against the salmonella bacteria that cause enteric fever. This bacteria is present in the animals' and humans' intestines and passes via feces and urine. The elevated levels of titers show a positive Widal test, indicating the presence of a recent or active infection.
Typhoid and paratyphoid fever are similar, but the latter is less severe.
Basically, a Widal test is a slide agglutination test that a healthcare professional suggests to find the antibodies in a blood test against the two antigens (O and H) of salmonella.
What is the purpose of the Widal test?
The Widal test aims to look for antibodies against somatic (O) and flagellar (H) antigens. The test analyzes the interaction between the antibodies and antigens in your blood sample.
If you are showing symptoms of typhoid fever, your healthcare provider may like to see your Widal test reports for better diagnosis.
What is the procedure for the Widal test?
The procedure of the Widal test is quick and simple. There is no need to fast before the test. During the test, the expert will insert a needle into the vein in your arm to draw a blood sample. Then, the expert will label it and send it to the laboratory for diagnosis.
Additionally, there are two methods to conduct a Widal test:
- Qualitative Test: In the qualitative method of Widal testing, the lab expert places one drop of undiluted serum on the slides in four reaction circles, i,e., O, H, AH, and BH. Then, he will mix the contents with a separate applicator and gently rock the slide for a minute. If there is any agglutination, your Widal test is positive.
- Quantitative Test: This method for Widal testing is a semi-procedure test that takes place after a positive qualitative test. It involves testing positive antigens with a blood sample to confirm the slide agglutination.
Note: In most cases, the S.typhi O and H are used to confirm you have an active fever. Only some people showed positive AH and BH during the qualitative test.
Also read: https://redcliffelabs.com/myhealth/lab-test/Widal-test-s-typhi-o-price-purpose-procedure-result/
Understanding the Widal Test Results and Range
Understanding the Widal test results and ranges typically depends on the titer value. To diagnose properly, the expert will include titers ranging from 1:20, 1:40, 1:60, 1:80, 1:160, and 1:200 and present a typhoid test report.
| Antigen | Titer | Interpretation |
| S Typhi normal range | > 1.160 | Indicates current or recent infection. |
| H-antigen | > 1.160 | Past infection or immunization |
| Rising titer | 1:40 to 1:80 to 1:160 | Recent infection |
A Widal test negative means O and H antigens are less than 1:160, and a value greater than 1.60 and 1:320 is considered positive.
Widal Test Positive in Detail
The Widal test positive means you have been infected with Salmonella enterica serovar Typhi bacteria. It is a crucial test result that needs to be taken seriously. It is because this bacteria is the main cause of typhoid fever.
When the Widal test range is equal to or more than 1:60 to 1:320 titer for antigens O and H, it shows positive results, indicating typhoid infection.
Furthermore, in a country like India, where typhoid is common due to inadequate sanitation and lack of clean drinking water, there is a possibility of fever from other cross-reactives due to malaria or non-typhoidal salmonella.
Do not worry; typhoid fever can be tackled through a specific diet and medication. Hence, discuss your Widal test reports with a healthcare professional to get the most suitable treatment and mitigate the negative consequences.
What are the limitations of the Widal test?
The Widal test is a quick, affordable, and effective diagnosis of typhoid fever. Like any other test, it has some limitations, including:
- The Widal test results can be falsely positive when diagnosed with a past S. typhi infection.
- A lot of time gets wasted during the Widal test. Treatment for typhoid fever cannot begin unless the diagnosis is made.
- Georges Ferdinand Widal’s test cannot differentiate between your past, present, or S. typhi vaccination.
- The Widal test results can be falsely positive in typhus, chronic liver disease, nephrotic syndrome, and chronic liver disease.
- Many factors can influence the Widal test results, making it less reliable to diagnose typhoid.
Book a Blood Test Online from Redcliffe Labs!
Download the Redcliffe Labs mobile app to book a blood test online for a Widal test. The Widal test price at Redcliffe Labs is just Rs 130. The phlebotomist will come with a blood sample collection kit, providing the convenience of a safe blood draw at home. Get the most accurate Widal test reports, typically within 12 hours.
Stepwise information on booking a blood test online from Redcliffe Labs.
- Visit the official Redcliffe Labs website: https://redcliffelabs.com/.
- Search for the specific test you need.
- Add the test to the cart.
- Complete the payment process online.
- You will receive confirmation through SMS and WhatsApp.
Note: A home sample collection facility for urine and stool culture tests is available with Redcliffe Labs.
Consult a doctor if you experience fever, tiredness, headaches, or vomiting symptoms. The doctor can suggest a Widal test to diagnose typhoid or enteric fever. The test requires blood and some reagents to check for infection.
Additionally, the specialist may suggest a blood test one week after the infection. Please do not skip his he gave, and thus, get treated as quickly as possible.
Frequently Asked Questions (FAQs)
1. Who should take the Widal test?
The Widal test is typically recommended for those individuals showing symptoms such as abdominal pain, gastrointestinal issues, high fever, and extreme fatigue, indicating typhoid.
2. How can I prepare for a Widal test?
No special preparation is required for a Widal test. You need not fast before the test, which means eating and drinking anything (except alcohol) is allowed.
3. How can you protect yourself from typhoid?
You can keep yourself protected from typhoid fever by getting access to clean water. Besides, adequate sanitation facilities, hygiene, and typhoid vaccination can help.
