Mantoux Test Explained: Normal Range, Positive Result Meaning, TB Diagnosis & What to Do (India 2026) | मंटोक्स टेस्ट गाइड
Mantoux Test Explained: Positive Result, mm Reading, BCG Vaccine & TB Diagnosis (India 2026)
मांटौक्स टेस्ट (TB स्किन टेस्ट): पॉजिटिव रिजल्ट, mm रीडिंग, BCG वैक्सीन और टीबी निदान गाइड
Your doctor has recommended a Mantoux test — and you are not sure what to expect during the 2–3 days of waiting, what the millimeter reading means, or whether a positive result means you have TB. The Mantoux test (also called the Tuberculin Skin Test or PPD test) is the most commonly used TB screening tool in India — ordered for persistent cough, unexplained fever and weight loss, medical clearances (visa, job medicals, school admissions), and contacts of known TB cases.
This guide explains the Mantoux test from injection to reading — the procedure, how to read the mm result, the BCG vaccine problem, and exactly what a positive result means for Indian patients. For understanding other infection markers ordered alongside TB tests, see our guide on the Complete Blood Count (CBC) and our ESR test guide.
मांटौक्स टेस्ट (PPD टेस्ट) भारत में सबसे आम TB स्क्रीनिंग टूल है। यह गाइड इंजेक्शन से लेकर रीडिंग तक सब कुछ समझाती है — प्रक्रिया, mm परिणाम, BCG वैक्सीन की समस्या, और पॉजिटिव रिजल्ट का सटीक अर्थ।👁 Table of Contents / विषय सूची
How the Mantoux Test Is Done / मांटौक्स टेस्ट कैसे किया जाता है?
Unlike a standard blood test, the Mantoux test is a skin test — it involves injecting a small amount of tuberculin (PPD — Purified Protein Derivative) under the skin, waiting 48–72 hours for the immune system to react, and then measuring the reaction.
सामान्य ब्लड टेस्ट के विपरीत, मांटौक्स टेस्ट एक स्किन टेस्ट है — त्वचा के नीचे थोड़ी सी tuberculin (PPD) इंजेक्ट करना, 48–72 घंटे प्रतिरक्षा प्रणाली की प्रतिक्रिया का इंतजार करना, और फिर प्रतिक्रिया मापना।
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Step 1 — The injection (Day 1)
A healthcare worker injects 0.1 mL of tuberculin (PPD — Purified Protein Derivative) just under the skin (intradermally) of your inner forearm. This immediately creates a small, pale bump (called a wheal) about 6–10 mm in diameter. This initial bump is NOT the reading — it will disappear within 30 minutes. The injection site should not be rubbed, scratched, or bandaged.
एक स्वास्थ्य कार्यकर्ता आपकी आंतरिक बांह की त्वचा के ठीक नीचे 0.1 mL tuberculin (PPD) इंजेक्ट करता है। यह तुरंत एक छोटा, पीला उभार बनाता है जो 30 मिनट में गायब हो जाता है — यह रीडिंग नहीं है। -
Step 2 — The reading (48–72 hours later)
Return to the clinic exactly 48 to 72 hours after the injection. Do not come earlier than 48 hours (the immune response may not have fully developed) and do not come after 72 hours (the reaction starts fading and gives falsely low readings). The doctor will feel and measure the raised, firm bump (induration) in millimeters using a ruler. The reading is the size of this bump — not the red area around it.
इंजेक्शन के ठीक 48 से 72 घंटे बाद क्लिनिक वापस जाएं। 48 घंटे से पहले न आएं और 72 घंटे के बाद न आएं। डॉक्टर उभरे हुए, कठोर हिस्से (induration) को मिलीमीटर में मापेंगे।
Reading the mm Result / mm रीडिंग कैसे समझें
The Mantoux result is given in millimeters (mm) of the induration (raised bump). Crucially, the positive threshold is NOT the same for everyone — it depends on your risk factors and whether you are in a high-prevalence country like India. The interpretation follows CDC and Indian NTEP (National Tuberculosis Elimination Programme) guidelines.
मांटौक्स परिणाम induration (उभरे हुए उभार) के मिलीमीटर में दिया जाता है। पॉजिटिव सीमा सभी के लिए समान नहीं है — यह आपके जोखिम कारकों पर निर्भर करती है।| Induration Size / उभार | Result in India | Who this applies to |
|---|---|---|
| 0 – 4 mm | Negative / सामान्य | No TB infection likely. No further investigation needed in an asymptomatic person. |
| 5 – 9 mm | Positive (high-risk groups only) | Positive threshold for: HIV patients, organ transplant recipients, recent close contacts of confirmed TB case, and patients on immunosuppressants (steroids, TNF inhibitors). |
| 10 mm or above | Positive (India — general population) | Positive for most adults in India (high TB prevalence country). Healthcare workers, laboratory workers, prisoners, children below 5 years, and those from other high-prevalence regions. |
| 15 mm or above | Positive (low-risk individuals) | Positive threshold for adults with no known TB risk factors in low-prevalence settings (e.g., visa medicals for travel to low-prevalence countries may use this threshold). |
Latent vs Active TB — The Critical Difference
Mantoux: Positive. Symptoms: None. The TB bacteria are dormant (asleep) inside your body, contained by your immune system. You feel completely well, have no cough, no fever, no weight loss. You cannot spread TB to others. However, if your immunity weakens in future (HIV, steroids, diabetes, old age), latent TB can reactivate. About 10% of people with LTBI develop active TB in their lifetime without preventive treatment.
Mantoux: Positive. Symptoms: Present. The bacteria are multiplying and causing disease. Symptoms: persistent cough (especially coughing blood or blood-stained sputum), unexplained weight loss above 10%, prolonged fever (especially low-grade in the evenings), night sweats, and extreme fatigue. Active TB is contagious — you can spread it to others through coughing. Requires urgent 6-month antibiotic therapy under NTEP/DOTS.
| Feature | Latent TB | Active TB |
|---|---|---|
| Mantoux result | Positive | Positive |
| Chest X-ray | Usually normal | Abnormal — shadows, cavities |
| Symptoms | None | Cough, fever, weight loss, night sweats |
| Contagious? | No | Yes — until 2 weeks of treatment |
| Sputum test | Negative | May be positive |
| Treatment needed? | Preventive therapy in selected cases | Yes — 6-month DOTS regimen |
BCG Vaccine & False Positives / BCG वैक्सीन और झूठी पॉजिटिव
This is the most common source of confusion for Indian patients with a positive Mantoux result. Almost all Indians receive the BCG (Bacillus Calmette-Guérin) vaccine at birth under the Universal Immunisation Programme. This vaccine contains a weakened form of a related mycobacterium — and the Mantoux test cannot always distinguish between immunity from the BCG vaccine and immunity from actual TB infection.
यह भारतीय रोगियों के लिए सबसे आम भ्रम का स्रोत है। लगभग सभी भारतीयों को जन्म पर BCG वैक्सीन मिलती है। यह वैक्सीन एक संबंधित माइकोबैक्टीरियम का कमजोर रूप है — और मांटौक्स टेस्ट हमेशा BCG वैक्सीन से प्रतिरक्षा और वास्तविक TB संक्रमण से प्रतिरक्षा के बीच अंतर नहीं कर सकता।BCG-related reactions typically produce a smaller induration (5–14 mm), tend to wane over time (a BCG-induced reaction often becomes negative 10–15 years after vaccination), and are more common when BCG was given after infancy. If you have a Mantoux reading of 10–14 mm with no risk factors, no symptoms, and were vaccinated with BCG in childhood, BCG-related reaction is one possible explanation — but cannot be assumed without further evaluation.
A very large induration (15 mm or above) is very unlikely to be due to BCG alone. A large reaction in someone with TB symptoms, known TB contact, or immunocompromise must be taken seriously regardless of BCG history. BCG does not explain a positive Mantoux decades after vaccination — the immune response from BCG fades significantly over time.
Mantoux vs IGRA (TB Gold Test) / IGRA से तुलना
When a Mantoux result is positive but the doctor is unsure whether it is due to BCG vaccination or true TB infection, the next step is often an IGRA (Interferon-Gamma Release Assay) — also marketed in India as the TB Gold test or QuantiFERON-TB Gold.
जब मांटौक्स परिणाम पॉजिटिव हो लेकिन डॉक्टर BCG टीकाकरण या वास्तविक TB संक्रमण के बारे में अनिश्चित हों, तो अगला कदम अक्सर IGRA (QuantiFERON-TB Gold) होता है।| Feature | Mantoux (TST) | IGRA (TB Gold) |
|---|---|---|
| Type of test | Skin test (2 visits needed) | Blood test (1 visit, lab processes) |
| Affected by BCG vaccine? | Yes — BCG can cause false positive | No — not affected by BCG |
| Reading window | Must return in 48–72 hours | Result in 1–2 days from blood draw |
| Specificity for TB | Lower (BCG interference) | Higher in BCG-vaccinated populations |
| Cost in India | ₹150–400 (very affordable) | ₹2,500–5,000 (significantly higher) |
| Availability | Available at any clinic/hospital | Requires NABL-accredited lab, not universally available |
| Best used for | Initial TB screening, mass screening, children | Resolving BCG-related false positives, visa medicals for developed countries, immunocompromised patients |
What to Do After a Positive Mantoux Result
The most important next step after a positive Mantoux. A chest X-ray reveals whether there are any active lung changes — infiltrates (patches), cavities, hilar lymphadenopathy, or old healed TB lesions. A normal chest X-ray with a positive Mantoux strongly suggests latent TB, not active disease. An abnormal X-ray warrants sputum examination and specialist evaluation.
If you have cough for more than 2 weeks, blood in sputum, unexplained fever, or weight loss — provide sputum samples for AFB smear microscopy and GeneXpert (CBNAAT). GeneXpert is now available at all government District TB Centres in India under NTEP — it is highly sensitive, specific, and provides drug resistance information simultaneously. It is free at government hospitals.
Doctors typically order an ESR and CBC alongside TB workup. Active TB typically causes a markedly elevated ESR (often above 100 mm/hr), anaemia of chronic disease (low haemoglobin), and a relative lymphocytosis (increased lymphocytes on differential count). A completely normal ESR and CBC makes active TB much less likely.
A positive Mantoux alone never requires TB treatment. A pulmonologist or NTEP-registered physician evaluates: symptom history, contact history, immune status, Chest X-ray and IGRA findings, and sputum results — before deciding whether treatment is needed and which regimen (active TB treatment or latent TB preventive therapy). Treatment decisions should never be made on blood or skin test results alone.
✅ Book Mantoux Test or TB Screening — Home Collection Available
If you have been advised a Mantoux test, TB Gold (IGRA), or full TB screening panel, you can book with home sample collection for blood-based tests and lab visits for the Mantoux skin test:
Affiliate link: I may earn a small commission at no extra cost to you. Prices as of April 2026. Home sample collection available across India for blood-based tests.
यदि आपको मांटौक्स टेस्ट, TB गोल्ड (IGRA) या पूर्ण TB स्क्रीनिंग पैनल की सलाह दी गई है, तो आप यहां बुक कर सकते हैं।Related Tests / संबंधित जांचें
These tests are commonly ordered alongside or after the Mantoux test for TB workup:
TB मूल्यांकन के लिए मांटौक्स टेस्ट के साथ या बाद में ये जांचें अक्सर करवाई जाती हैं:Frequently Asked Questions / अक्सर पूछे जाने वाले सवाल
A positive Mantoux test — 10 mm or more in India for most adults — means your immune system has been exposed to TB bacteria at some point in your life. It does NOT confirm that you currently have active, infectious TB. Most people with a positive Mantoux in India have latent TB — the bacteria are dormant, you have no symptoms, and you cannot spread it to others. To determine if you have active TB, your doctor will need a Chest X-ray, symptom assessment, and possibly sputum examination. Never start TB medication based on a positive Mantoux alone.
उत्तर: पॉजिटिव मांटौक्स — भारत में अधिकांश वयस्कों के लिए 10 mm या अधिक — का मतलब है कि आपकी प्रतिरक्षा प्रणाली किसी समय TB बैक्टीरिया के संपर्क में आई है। इसका मतलब सक्रिय TB नहीं है।Yes — you can bathe normally. Water exposure does not affect the Mantoux test reaction. However, during the 48–72 hour waiting period, do NOT scratch, rub, or scrub the injection site on your arm, do NOT apply any lotion, cream, or ointment to the area, do NOT cover it with a bandage or plaster, and do not apply ice or heat. Simply pat the area gently dry with a towel after bathing. Scratching or rubbing the site can cause false inflammation that makes the reading inaccurate.
उत्तर: हां — सामान्य रूप से नहा सकते हैं। 48–72 घंटे की प्रतीक्षा अवधि में: खरोंचें या रगड़ें नहीं, लोशन या पट्टी न लगाएं। बस तौलिये से धीरे से सुखाएं।Yes — the BCG vaccine given at birth in India can cause a false positive Mantoux reaction, typically producing an induration of 5–14 mm. This is one of the most important clinical considerations in India, where virtually everyone has received BCG. However, BCG-induced reactions tend to wane over time (often becoming negative 10–15 years after vaccination), and a very large induration (above 15 mm) is unlikely to be due to BCG alone. If your doctor suspects a BCG-related false positive, they will recommend a TB Gold test (IGRA — Interferon-Gamma Release Assay), which is a blood test that is NOT affected by BCG vaccination and more accurately reflects true TB infection.
उत्तर: हां — BCG वैक्सीन से झूठी पॉजिटिव प्रतिक्रिया हो सकती है, आमतौर पर 5–14 mm induration। डॉक्टर IGRA (TB Gold) का सुझाव दे सकते हैं, जो BCG से प्रभावित नहीं होता।The Mantoux test (TST) is a skin test that requires two visits (injection + reading after 48–72 hours) and costs ₹150–400. It can give false positives in BCG-vaccinated people. The IGRA (Interferon-Gamma Release Assay) — marketed as TB Gold or QuantiFERON-TB Gold — is a blood test requiring only one visit, costs ₹2,500–5,000, and is NOT affected by BCG vaccination. IGRA is more specific for true TB infection in BCG-vaccinated populations. Doctors in India typically use IGRA when: the Mantoux result is equivocal, the patient has a strong BCG history, visa medicals for low-prevalence countries are required, or the patient is immunocompromised. IGRA is not routinely available in all government facilities but is available in major urban private labs.
उत्तर: मांटौक्स: स्किन टेस्ट, 2 विज़िट, ₹150–400, BCG से प्रभावित। IGRA/TB Gold: ब्लड टेस्ट, 1 विज़िट, ₹2,500–5,000, BCG से प्रभावित नहीं। IGRA BCG-टीकाकृत आबादी में अधिक विशिष्ट।Yes — a false negative Mantoux test is possible. The Mantoux test can be falsely negative (negative despite TB infection) in: HIV patients (weakened immune response — cannot mount a skin reaction), severe malnutrition, the very elderly, recent TB infection within the last 8–10 weeks (the immune response hasn't developed yet), patients on immunosuppressive drugs (steroids, chemotherapy, TNF inhibitors), overwhelming active TB (immune system is overwhelmed), viral infections (including COVID-19, measles), or if the injection was given incorrectly. In high-clinical-suspicion patients with a negative Mantoux, doctors do not rule out TB — they proceed with IGRA, Chest X-ray, and sputum examination.
उत्तर: हां — झूठी नेगेटिव संभव है। HIV रोगियों, गंभीर कुपोषण, बहुत बुजुर्गों, इम्यूनोसप्रेसिव दवाओं पर, या हाल ही में (8–10 सप्ताह के भीतर) TB संपर्क में आए लोगों में मांटौक्स गलत तरीके से नेगेटिव आ सकता है।The Mantoux test always requires two visits. Visit 1: the tuberculin injection is given. You must wait exactly 48–72 hours. Visit 2: the doctor measures the induration (raised bump). You cannot skip Visit 2 or read the result yourself — accurate measurement requires a trained healthcare professional. If you miss the 48–72 hour window (come earlier than 48 hours or later than 72 hours), the result may be inaccurate and the test may need to be repeated. The Mantoux test cannot be done at home or from a simple blood draw — unlike the IGRA/TB Gold test which requires only a single blood draw.
उत्तर: मांटौक्स टेस्ट हमेशा दो विज़िट की आवश्यकता है। विज़िट 1: इंजेक्शन। 48–72 घंटे प्रतीक्षा। विज़िट 2: डॉक्टर induration को मापते हैं। यदि 48–72 घंटे की खिड़की छूट जाए तो परिणाम अमान्य हो सकता है।⚠️ Medical Disclaimer / चिकित्सा अस्वीकरण
This article is for educational purposes only. A positive Mantoux test requires clinical evaluation by a pulmonologist or infectious disease specialist to determine whether further investigation or treatment is necessary. Never self-diagnose or start TB medication based on a skin test or blood test result alone.
यह लेख केवल शैक्षिक उद्देश्यों के लिए है। पॉजिटिव मांटौक्स टेस्ट आने पर हमेशा एक योग्य पल्मोनोलॉजिस्ट से परामर्श लें। केवल स्किन टेस्ट के आधार पर TB की दवा कभी न शुरू करें।
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