The Mantoux test is a diagnostic skin test used in the diagnosis of tuberculosis (TB). It is also known as a Pirquet test or tuberculin sensitivity test (TST). The Mantoux test helps assess the immunological response exhibited on the skin when a patient has been exposed to the tuberculosis carrier germs. Tuberculosis is a serious bacterial infection that affects the lungs and can also impact the brain, kidneys, and spine. It spreads through coughing, sneezing, and from an organ donated by an already infected individual.

Many people infected with tuberculosis don't experience any symptoms because the bacteria may be dormant. This is known as "latent TB infection." Some people may develop active tuberculosis as a result of latent TB infection. The Mantoux test helps determine if a person has been infected with the tuberculosis bacteria.

When should I get the Mantoux Test?

The Mantoux test may be recommended by a healthcare provider if:

• A person exhibits symptoms of active tuberculosis
• A person is at risk of developing tuberculosis
• Someone who has been exposed to an already infected person without their knowledge
• A person has a medical condition which weakens their immune system (immuno-compromised individuals)
• Someone who has recently travelled to a region where tuberculosis is endemic.

Procedure for Mantoux /Tuberculin Sensitivity Test (TST)

The Mantoux test procedure is typically administered by a phlebotomist, who injects a small amount of protein extracted from dead tuberculosis bacteria beneath the upper layer of the skin on the forearm. A sterile disposable needle is used for this purpose. Before inserting the needle, the area is properly sterilised to prevent any interference or infection.

After the injection, a bump may appear at the injection site, which may disappear within 20 minutes. A small bump may gradually develop at the injection site over the next few days. It is important to visit a doctor's clinic or a certified healthcare provider for an assessment of the lump. The size of the lump needs to be measured to determine if the person has a tuberculosis infection.

Please note:

• Do not scratch or rub the area of the injection.
• Do not cover the site of the lump.
• If blisters develop, use a cool compress.

Uses of Mantoux /Tuberculin Sensitivity Test (TST)

A Mantoux test is performed to determine if a person has latent tuberculosis. It is often recommended for healthcare workers before they start working in the healthcare sector and for individuals who have travelled to regions where tuberculosis is common.

How to prepare for the Mantoux /Tuberculin Sensitivity Test (TST) 

Before the Mantoux test is done, it is important to let the doctor or healthcare provider know if:

• There has been a previous treatment for tuberculosis
• The Mantoux test has been performed before
• There was an episode of viral infection within the last week before the test
• The patient is immuno-compromised
• The patient is taking any medications that affect the immune system
• Any vaccination was received within the last month before the test

Why the ESR test is done

The ESR (erythrocyte sedimentation rate) test is a non-specific blood test that measures the rate at which red blood cells settle at the bottom of a tube over a specified period of time, usually one hour. The test is conducted by placing a blood sample in a vertical tube, and the rate of sedimentation is measured in millimeters per hour (mm/hr). The ESR test is not a diagnostic test on its own, but it can provide valuable information to healthcare professionals in the context of a broader clinical assessment.

The main reasons why the ESR test is done include:

• Inflammation Detection: The ESR is often used as a marker of inflammation in the body. In various inflammatory conditions, such as infections, autoimmune diseases, and certain cancers, the level of inflammation can cause changes in the proteins in the blood, leading to an increased sedimentation rate.
• Monitoring Disease Activity: The test may be used to monitor the progression or activity of certain inflammatory conditions, such as rheumatoid arthritis or temporal arteritis.
• Diagnostic Aid: While the ESR is not specific to any particular disease, abnormal results can prompt further investigation and help healthcare professionals narrow down potential causes of symptoms.
• Infection Screening: In some cases, an elevated ESR may indicate the presence of an infection, although it is not specific to any particular type of infection.

Mantoux Test Results

The Mantoux test result is based on the reaction of the injection on the skin. The reaction should be checked by a doctor or medical professional within 48 to 72 hours of injection. The lump formed on the skin has to be measured on a scale of millimetres without considering the surrounding redness of the skin. The lump has to be measured across the forearm. 

The interpretation of the Mantoux test result depends on different factors such as :

• The age of the patient
• Medical history of the patient
• Whether there has been a previous TB infection
• Whether the person has received a BCG vaccine

Classification of Mantoux Test Result

Here is a reference to the Mantoux test normal range.

Mantoux Test Positive Result

Mantoux test positive means a likely exposure to TB bacteria but does not imply that the person has active TB. If there are no TB symptoms, it means the person is not currently at risk for spreading the bacteria, but they may develop the disease in the future. The decision about treating latent TB should be made by a doctor who can assess the person's risk factors for developing active TB. The doctor may also recommend additional diagnostic tests to confirm TB.

Mantoux Test Negative Result

A negative result on the Mantoux skin test suggests that the person is unlikely to have been exposed to tuberculosis bacteria. A negative result is interpreted when there is no skin reaction. However, a doctor or healthcare provider may recommend further tests to definitively rule out tuberculosis, especially if there are symptoms of TB.

Conclusion

Tuberculosis testing and screening are essential for public health and safety. If left untreated, tuberculosis may turn deadly. Both active and latent tuberculosis require medical treatment to prevent spreading and complications in the infected person.    

FAQs 

1. What is a positive Mantoux test?

A positive Mantoux test may indicate that the person has been exposed to TB bacteria and has a latent form of TB.

2. Who needs a Mantoux test?

The Mantoux test may be recommended for those who: 

• Have travelled to endemic regions
• Have had a previous TB test
• Are healthcare workers starting in the healthcare sector
• Have been recently exposed to the bacteria
• Are immunocompromised
• Are candidates for receiving the BCG vaccine

3. Can the Mantoux test cause fever?

Yes, it is possible to develop a fever after taking the Mantoux test. However, such side effects are rare. This can be managed with medication under the direction and supervision of a doctor.

4. Is the Mantoux test confirmatory for TB?

A positive or negative response to the Mantoux test may indicate the presence or absence of TB bacteria, whether in the active or latent form. Additional tests may be recommended to diagnose or rule out tuberculosis.