A positive test result for tuberculosis (TB) means the Mycobacterium tuberculosis bacteria are present in your body. This result initiates a medical and public health process designed to determine the state of the infection and ensure proper treatment. Understanding the next steps is the best way to manage this diagnosis and move toward recovery.
Confirming the Diagnosis: Latent vs. Active TB
Following a positive screening test (such as TST or IGRA), the primary step is determining if you have Latent TB Infection (LTBI) or Active TB Disease. The initial positive result indicates exposure, not necessarily active illness. Most positive results are LTBI, where the bacteria are dormant, contained by the immune system, and not causing symptoms.
A person with LTBI is asymptomatic and cannot spread the bacteria. Active TB Disease occurs when the bacteria multiply, overcoming immune defenses and causing illness. Active disease typically causes symptoms such as a persistent cough, unexplained weight loss, night sweats, and fever.
To rule out Active TB Disease, healthcare providers use additional tests. A chest X-ray is performed to look for abnormalities in the lungs characteristic of active infection. If the X-ray is concerning or symptoms are present, a sputum sample is collected for laboratory analysis.
The sputum is examined via a smear test and a culture. If follow-up tests are negative and the patient is asymptomatic, the diagnosis is confirmed as LTBI. Treatment protocols differ significantly between the two forms.
The Treatment Protocol and Adherence
The treatment regimen depends on whether the infection is latent or active. Treating LTBI is a preventive measure intended to kill the dormant bacteria and stop progression to active disease. LTBI treatment often involves a shorter course, such as a three- or four-month rifampin-based regimen, or a longer course of isoniazid for six to nine months.
Active TB Disease requires more intensive, multi-drug regimens to eliminate multiplying bacteria and prevent drug resistance. The standard initial phase of therapy typically utilizes four different medications: isoniazid, rifampin, pyrazinamide, and ethambutol. This intensive phase usually lasts for two months.
The continuation phase often reduces the medication to a combination of two drugs, generally isoniazid and rifampin, for an additional four to seven months. The entire course of treatment for Active TB often spans six to nine months, depending on the severity and site of the infection. Regular monitoring is performed throughout this process to check for potential side effects, such as signs of liver toxicity.
Completing the full course of therapy is necessary to cure the infection and prevent drug resistance, even after symptoms subside. To ensure adherence, Directly Observed Therapy (DOT) is often recommended, especially for active disease. DOT involves a healthcare worker watching the patient swallow every dose of medicine.
DOT significantly improves treatment completion rates compared to self-administered therapy. It also allows the healthcare team to check for side effects and address barriers the patient may face. Failure to complete the prescribed regimen can result in a relapse of the infection with a form of the bacteria that is much harder to treat.
Protecting Others and Public Health Reporting
Active TB Disease is a nationally reportable condition, requiring your healthcare provider to notify the local public health department upon diagnosis. This initiates control measures necessary to limit the spread of infection within the community. The public health department manages the case from a community perspective.
Contact tracing begins immediately to identify individuals who shared air space with you during the infectious period. Investigators will interview you to establish a list of close contacts and sites of exposure, including household members, friends, and coworkers.
These contacts are notified, tested for TB infection, and offered LTBI treatment if positive. The goal is to quickly treat infected persons to break the chain of transmission. To protect your privacy, the health department will not disclose your name to the people being contacted.
If you have Active TB, you must follow specific infection control guidelines to prevent airborne transmission. This typically involves temporary isolation until you are no longer infectious, confirmed by decreased symptoms and negative sputum test results. Guidelines include staying home, avoiding public transportation, covering your mouth and nose when coughing or sneezing, and wearing a mask when around others.