How is Typhoid Detected?

Typhoid Detection Explained: Medical History, Cultures & PCR Testing 

Around 11-21 million people worldwide are affected by typhoid every year. Typhoid fever generally manifests as high fever with flu-like symptoms and diarrhoea that can last for weeks, making a patient weaker with time.

It is caused by a bacterium named Salmonella typhi, which can become life-threatening if not treated with proper antibiotics. Hence, it is essential to have a prompt diagnosis and start the treatment as soon as possible.

Keep scrolling to learn more about the diagnostic procedures to detect typhoid fever. 

What are the Different Diagnostic Tests to Detect Typhoid Fever?

Several diagnostic tests are necessary to detect typhoid fever. Listed below are a few of those diagnostic tests:

1. Examination of Medical History

At first, the healthcare professional will ask for a proper medical history to examine the following:

• How long have you been experiencing symptoms such as fever, weakness, abdominal pain, or diarrhoea
• If you’ve consumed water or food from any unknown or contaminated source
• If you have rashes on your chest region
• If you’ve had direct or indirect contact with any person suffering from or recovering from typhoid fever
   

 2. Blood Culture

The blood culture test is considered the gold standard typhoid test. In this test, the bacteria responsible for typhoid, Salmonella typhi, are isolated from the blood sample. The most accurate timing of sample collection is the first week of the illness.

 3. Serological Tests

The serological test consists of 2 tests: the Widal Test and the Typhi Dot Test. In the Widal test, antibodies against Salmonella typhi are detected in the blood sample. The Typhi Dot also detects antibodies against Salmonella typhi, but much faster.

However, it is not advisable to completely rely on these tests, as the Widal Test sometimes shows false-positive results.

 4. Urine and Stool Cultures

Although urine and stool samples are also collected to detect typhoid, they are much less reliable than the blood culture test. In this test, the causative bacteria is detected in the urine and stool samples. However, it is challenging to detect in the early stages of infection.

5. Bone Marrow Culture

This test is done when all the other tests mentioned above show inconclusive results. The bone marrow culture test is highly useful for detecting Salmonella typhi bacteria. In this process, a skilled and efficient healthcare professional extracts a sample of bone marrow through a iliac crest aspiration.

6. Rapid Diagnostic Tests

The mechanism of action is similar to that of Typhi Dot, which provides results within an hour. 
Note: Rapid diagnostic tests cannot reliably distinguish between current and past infection and should not be used alone to guide treatment decisions.

7.  Polymerase Chain Reaction

This is a molecular test that detects Salmonella typhi DNA, which results in early detection. Drug-resistant strains are also identified through this test.

Since typhoid is a life-threatening disease, it is essential to get it diagnosed as soon as possible. The gold standard test for typhoid is the blood culture test, which detects the growth of Salmonella typhi in the blood sample. Specific other tests include the Widal Test, the Typhidot Test, and urine and stool culture.

Reader Information: This article is intended for general informational and educational purposes only and does not constitute medical advice, diagnosis, or treatment. Diagnostic tests and treatment decisions for typhoid fever should always be made by a qualified healthcare professional based on clinical evaluation, laboratory findings, and current medical guidelines. Readers are advised to seek timely medical attention if they experience symptoms suggestive of typhoid fever or any other illness. 

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