Culture AFB Test

Culture-AFB is the gold standard test for detecting the presence of tuberculosis causing microorganisms. Tuberculosis is caused by Mycobacterium tuberculosis, which is an acid fast bacillus. Your doctor may suggest this test if you show symptoms related to lung infection or pulmonary tuberculosis. Common symptoms include chronic cough which produces sputum with bloody streaks, loss of appetite, fever, night sweats, chills, chest pain and unexplained weight loss. The symptoms of tuberculosis or other mycobacterial infections vary depending on the part of the body that is affected, such as the spine or the bone marrow.

For this test, it is advisable to be prepared early in the morning before breakfast. Rinse your mouth thoroughly as you will have to give a sputum sample. There is no special preparation required. You may however check with your doctor if you have any specific measures to take before arriving for the test. If your doctor intends to take Gastric Lavage specimens, you may have to fast overnight. This type of specimen is taken if the patient has difficulty in coughing up sputum. Usually, specimen from children and infants is taken through Gastric Lavage.

This test helps identify which mycobacterium is causing disease in the patient. The test culture will also help identify which drugs may or may not work on the bacteria. A positive test after several weeks of treatment may indicate that the treatment is not effective and will have to be changed. A negative test means that you do not have an active mycobacterial infection. In case of latent infection, it is possible that you may not have any symptoms, but the test will show positive result. If you are undergoing treatment for tuberculosis, you doctor will order an AFB culture every month to monitor effectiveness of treatment.

For this test, you will have to cough up several times to collect sputum in a sterile cup. If you are not able to cough up enough sample, you will be asked to inhale a warm sterile solution that will make you cough. Even if this method does not work, a tube will be inserted via your mouth or nose into the stomach to collect swallowed sputum. If this also fails, a bronchoscope may be put into your lungs to remove tissue or sputum sample. This is done under anesthesia, so you won’t feel any pain.