MTB Susceptibility – Ethambutol Test: Booking, Price, and Results
About MTB Susceptibility – Ethambutol Test: Booking, Price, and Results
| Field | Value |
|---|---|
| Also Known As | Ethambutol Drug Susceptibility Test, EMB DST, MTB Antibiogram – Ethambutol, Ethambutol AFB Sensitivity Test |
| Sample Type | Aspirate, Bronchoalveolar Lavage (BAL), Bile, Bone Marrow, Bronchial Fluid, Catheter Tip, Corneal Scraping, Cerebrospinal Fluid (CSF), Endotracheal Secretion, Gastric Fluid, Hair Clipping, Liver Abscess Fluid, Nail, Pericardial Fluid, Peritoneal Fluid, Pleural Fluid, Sputum |
| Fasting Required | No |
| Report Time | 29 days |
| Recommended For | All genders and ages; patients with confirmed or suspected TB infection |
| Price | Starting at ₹2,200 |
What Is an MTB Susceptibility – Ethambutol Test?
The MTB Susceptibility – Ethambutol test checks whether the bacteria that cause tuberculosis (Mycobacterium tuberculosis) respond to the antibiotic ethambutol. It is also called the Ethambutol Drug Susceptibility Test or EMB DST. Doctors order this test to guide TB treatment decisions for patients with confirmed or suspected TB or for those whose current treatment is not producing the expected response. The sample can be sputum, bronchial lavage fluid, a pure culture isolate or several other clinical specimens depending on the patient's condition.
What Does an MTB Susceptibility – Ethambutol Test Measure?
This test evaluates how the TB bacteria respond to ethambutol under laboratory conditions. The results guide treatment decisions by showing whether the drug is effective against the specific strain of bacteria present. The key areas assessed are listed below.
| Parameter | What It Tells You |
|---|---|
| Ethambutol susceptibility | Whether ethambutol can inhibit or kill the TB bacteria |
| Growth inhibition (phenotypic method) | Whether TB bacteria grow in the presence of ethambutol at a critical concentration of 5 µg/mL |
| embB gene mutations (molecular method) | Whether gene-level changes linked to ethambutol resistance are present |
Why Is an MTB Susceptibility – Ethambutol Test Done?
This test is performed to ensure patients receive the right anti-TB drugs. Testing helps prevent ineffective treatment, reduces transmission, and lowers the risk of further drug resistance developing.
Common Symptoms That May Require This Test
The following symptoms often lead a doctor to investigate TB and order susceptibility testing.
- Persistent cough lasting more than three weeks
- Fever and chills
- Night sweats
- Unexplained weight loss
- Loss of appetite
- Fatigue and general weakness
- Coughing up blood or discoloured sputum
Conditions This Test Can Help Detect
Doctors use the MTB Susceptibility – Ethambutol test to identify or guide the management of several TB-related conditions.
- Ethambutol-susceptible tuberculosis, where the drug can be included in the standard first-line regimen
- Drug-resistant tuberculosis, where ethambutol is no longer effective
- Multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB)
- Treatment failure or relapse cases requiring a fresh review of the drug regimen
MTB Susceptibility – Ethambutol Test for Chronic Disease Monitoring
For patients undergoing TB treatment, this test helps doctors confirm that the chosen drug regimen is appropriate. In cases of MDR-TB, cultures are typically performed monthly throughout the course of treatment. Repeat susceptibility testing may be ordered to track treatment response and detect any newly emerging resistance.
How to Prepare and What to Expect
No special preparation is required for the MTB Susceptibility – Ethambutol test procedure, but following a few practical steps ensures a good-quality sample.
Do You Need to Fast?
No fasting is required for this test. There are no dietary restrictions before giving the sample. However, if a sputum specimen is needed, it is best collected in the early morning, before eating, drinking, smoking or brushing your teeth.
Practical Tips Before Your Test
The following steps help ensure the sample is suitable for testing.
- Bring a detailed clinical history including your symptoms, previous test results and relevant medical records, as well as your full address and mobile number, as these are required for this test
- Inform the doctor or technician about all medications you are currently taking
- If sputum is the sample type, rinse your mouth with clean water before collection
- Ensure you cough deeply from the lungs when producing a sputum sample, not just from the throat
- Avoid strenuous physical activity before the appointment
Step-by-Step Procedure
The sample collection method varies depending on the site of infection. The steps below cover sputum collection, the most common approach, though other specimen types such as BAL, CSF or tissue may be collected by a healthcare professional at the centre.
- Arrive at the Lupin Diagnostics centre and hand over your clinical history and any prior test reports.
- For sputum collection, rinse your mouth with water. Take a deep breath, hold it for five seconds, breathe out slowly, then take another deep breath and cough hard to bring up phlegm from deep in the lungs.
- Spit the sputum into the sterile container provided. A minimum of 5 ml is needed. At least three specimens are typically required, collected at 8 to 24-hour intervals, with at least one collected early in the morning.
- The container is sealed, labelled and stored under refrigerated conditions (2 to 8 degrees Celsius) for transport to the laboratory.
- In the laboratory, the sample is processed using an automated method. The bacteria are cultured and exposed to ethambutol.
- Results are prepared and dispatched within 29 days. You will receive your report digitally.
Factors That Can Affect Accuracy
Several factors can influence the reliability of results.
- Poor sample quality (saliva instead of lung sputum)
- Starting anti-TB therapy before sample collection
- Delayed transport or inadequate refrigeration of the specimen
- The narrow difference in minimum inhibitory concentrations between resistant and susceptible strains, which can affect reproducibility
- Variation in results across different testing methods (such as MGIT, agar proportion or microdilution)
Understanding Your MTB Susceptibility – Ethambutol Test Results
Results are reported as either 'sensitive' or 'resistant'. Your doctor will review these findings alongside your full clinical picture before making any treatment decisions.
| Result | Interpretation |
|---|---|
| Sensitive | TB bacteria respond to ethambutol; the drug can be included in the treatment regimen |
| Resistant | TB bacteria do not respond to ethambutol; alternative or second-line drugs are needed |
These ranges are general guidelines. Your doctor will interpret your results based on your age, health history and other factors. Always consult a qualified healthcare professional for personalised medical advice.
Results During Special Conditions
Certain factors can make result interpretation more complex:
- The bacteriostatic nature of ethambutol and the narrow gap between susceptible and resistant strain thresholds can make test reproducibility challenging.
- Differences in results across testing methods (MGIT, agar proportion and microdilution) are well documented for ethambutol and should be considered when interpreting findings.
- Prior anti-TB therapy may also inhibit bacterial growth and affect the outcome.
How to Maintain Healthy Levels
The following general wellness steps support a better outcome during TB treatment:
- Complete the full prescribed course of TB treatment without skipping doses.
- Follow infection control practices, such as covering your mouth when coughing, to prevent transmission.
- Attend all scheduled follow-up appointments so your doctor can monitor your response to treatment.
- Maintain good nutrition and rest to support your immune system during treatment.
Lupin Diagnostics MTB Susceptibility – Ethambutol Test Price
The MTB Susceptibility – Ethambutol test cost at Lupin Diagnostics starts at ₹2,200. This test requires a visit to a Lupin Diagnostics centre; home collection is not available.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 2200 |
| CHENNAI | 2200 |
| HYDERABAD | 2200 |
| KOLKATA | 2200 |
| NAVI MUMBAI | 2200 |
| PUNE | 2200 |
Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
MTB Susceptibility – Ethambutol test online booking is available through the Lupin Diagnostics website. Follow these steps.
- Select the MTB Susceptibility – Ethambutol test on the Lupin Diagnostics website.
- Choose your city and preferred centre location.
- Visit the centre at your scheduled time for sample collection.
- Receive your report via email or WhatsApp within the stipulated turnaround time.
Frequently Asked Questions
The MTB Susceptibility – Ethambutol test checks whether the TB bacteria (Mycobacterium tuberculosis) in your body can be inhibited or killed by the antibiotic ethambutol. The result tells your doctor whether ethambutol is a suitable drug for your treatment plan.
The MTB Susceptibility – Ethambutol test is ordered for patients with confirmed or suspected TB. Doctors order it to make sure the anti-TB drugs prescribed are actually effective against the specific strain of bacteria causing your infection. Without accurate drug susceptibility results, treatment may fail, and resistance can develop further.
A wide range of specimens can be submitted, including sputum, bronchial fluid, bronchial alveolar lavage, pure culture isolates, tissue, urine, pus, swabs and several other clinical specimens. Your doctor will advise which type is appropriate in your case.
The report for this test is delivered within 29 days. Culture-based susceptibility testing takes time because the bacteria must be grown and then exposed to the antibiotic under controlled laboratory conditions.
A resistant result means that ethambutol can no longer effectively kill the TB bacteria in your body. This does not mean treatment is not possible; it means your doctor will need to consider alternative or second-line TB medications.
No. Due to the specialised collection requirements and infection control considerations for TB samples, this test must be done at a Lupin Diagnostics centre. You can book your appointment through the Lupin Diagnostics website.
You must bring a detailed clinical history, including your symptoms, previous test results and any relevant medical records. Your complete address and mobile number are also required at the time of sample collection.
MTB Susceptibility – Ethambutol Test: Booking, Price, and Results
