Learn how an AFB test diagnoses tuberculosis. Understand the sputum test process, benefits, and how results guide your treatment. Explore more here!
| Category | Details |
|---|---|
| What are AFB tests? | AFB tests detect Acid-Fast Bacillus bacteria, causing tuberculosis (TB) and other mycobacterial infections like leprosy. |
| Types of AFB Tests | – AFB Smear: Sputum sample smeared on a slide and viewed under a microscope (results in 1-2 days).- AFB Culture: Sputum sent to lab to grow bacteria (results in 6-8 weeks).- Molecular Test (NAAT): Detects TB and resistance to rifampicin (results in less than 2 hours).- Susceptibility Test: Determines which antibiotics are most effective for treatment. |
| Purpose of AFB Tests | – Diagnose active TB.- Identify other AFB infections (e.g., leprosy, Mycobacterium avium).- Monitor treatment progress for people already diagnosed with TB. |
| Symptoms of Active TB | – Pulmonary TB: Cough lasting 3+ weeks, chest pain, coughing up blood or sputum.- Other Symptoms: Chills, fever, night sweats, fatigue, unexplained weight loss, back pain (spinal TB), headache (TB meningitis), joint pain, abdominal pain. |
| Risk Factors | – Recent TB infection.- Weakened immune system (e.g., HIV, diabetes, substance use, organ transplant, cancer treatments).- Contact with someone with TB.- Living/working in high-risk areas (e.g., homeless shelters, prisons). |
| Test Procedure | – Sample Collection: Cough into a sterile container to provide sputum. If needed, a saline mist or bronchoscopy (tube inserted into airways) may be used to collect sputum. |
| Preparation | No special preparation required. |
| Risks | – No risk from coughing sputum.- Minor risks from bronchoscopy: sore throat, small risk of infection or bleeding. |
| Test Results | – Negative Smear/Culture: Likely no active TB, or not enough bacteria to detect.- Positive Smear: Likely TB or other infection, needs culture confirmation.- Positive Culture: Confirms active TB or another AFB infection.- Positive NAAT: Confirms TB.- Susceptibility Test: Identifies effective antibiotics. |
| Treatment | TB can be cured with antibiotics, but treatment takes 6-12 months. Follow the treatment plan fully to avoid relapse. |
| Important Notes | TB can be deadly if untreated. After a few weeks of antibiotics, TB is no longer contagious, but you must complete the full course to cure it. |