Key Facts About Tuberculosis
Tuberculosis (TB) is a potentially serious infectious disease that mainly affects the lungs. It has impacted human health for millennia and still poses a significant global health threat. Understanding the key fundamentals of TB is important for diagnosis, treatment and prevention.
How TB Spreads
TB is an airborne disease caused by the bacteria Mycobacterium tuberculosis. It spreads through the air when someone sick with TB coughs, sneezes or speaks. Prolonged exposure to the bacteria is usually needed for transmission.
TB Primarily Affects the Lungs
In most cases, TB causes infection in the lungs (pulmonary TB). The bacteria can also spread to other sites like the kidneys, spine and brain (extrapulmonary TB). When active, TB disease can be serious and lead to respiratory failure if left untreated.
Latent TB Infection is Possible
Not everyone infected with TB bacteria becomes sick. People can harbor latent TB infection where they test positive but don't have active symptoms. About 10% of latent cases eventually progress to active, contagious TB disease.
Multidrug-Resistant TB is an Emerging Concern
Standard antibiotics can treat most uncomplicated TB cases. But multidrug-resistant TB (MDR-TB) has evolved and does not respond to first-line meds. Treating MDR-TB is challenging, requiring extended, specialized regimens.
Signs and Symptoms of Active TB Disease
Recognizing symptoms consistent with active pulmonary TB aids early intervention to treat infection and curb transmission. Signs usually develop slowly and may include:
Persistent Cough
A cough lasting 3 or more weeks is a hallmark symptom, occasionally producing blood-tinged mucus. The prolonged cough results from lung inflammation and irritation.
Fever and Chills
Low-grade fever commonly accompanies active TB. Drenching night sweats from fever spikes also occur. General chills, fatigue and appetite loss often coincide with the fever.
Unintentional Weight Loss
When fighting active TB infection, the metabolism revs up. This fuels weight loss of over 1.5 pounds weekly without intentional dieting. Wasting signals TB severity.
Chest Pain
Advanced lung TB leads to painful coughing. The infection itself also causes chest soreness from inflamed lung tissue and membranes. Back pain can result from coughing fits.
Other Varied Symptoms
Symptoms depend on where TB bacteria spread outside the lungs. This includes night sweats, headache, vision changes or loss, nausea, abdominal pain, enlarged lymph nodes, joint swelling and more.
Testing Methods to Diagnose TB
Accurately diagnosing TB involves assessing infection likelihood based on risk factors plus utilizing various tests to detect presence of TB bacteria and disease activity.
Risk Assessment
Exposure history through work/travel in high-prevalence regions or contact with someone having active TB raises infection chances. Underlying health conditions also increase susceptibility.
Tuberculin Skin Test
Injecting PPD tuberculin extract under the skin checks for immune sensitivity signaling latent or active TB. Some limitations exist with false negatives/positives.
IGRA Blood Tests
Tests like QuantiFERON check immune cells reaction to TB proteins. This also diagnoses latent TB. IGRA avoids false positives associated with BCG vaccine.
Chest X-Ray
Imaging often shows lung damage from active TB like masses, nodules and scarring not visible on basic chest X-rays early on. Useful for monitoring treatment efficacy.
Microscopic Sputum Analysis
Checking sputum samples for TB bacteria under a microscope provides confirmation of active pulmonary TB. Allows assessing bacterial load and drug resistance patterns.
NAAT Testing
Rapid diagnostic nucleic acid amplification tests like Xpert MTB/RIF identify TB DNA in sputum samples. Also detects genetic resistance markers for precision treatments.
Treating Active and Latent TB Infection
Medication Regimens
Treatment for active TB uses antibiotic combinations like isoniazid, rifampin, ethambutol and pyrazinamide via daily dosing for at least 6 months to eliminate bacteria.
Multidrug-Resistant TB Therapy
Resistant TB strains require customized therapy with special second-line injectables like amikacin plus other intensive regimens lasting up to 2 years.
Latent TB Antibiotic Treatment
Those with latent TB unlikely to progress get preventive antibiotic therapy - usually isoniazid for 3-9 months. This eliminates lingering bacteria and lowers reactivation odds.
Directly Observed Therapy
Health professionals directly monitor patients taking oral antibiotics to ensure compliance essential for preventing resistance and cure. This DOT approach improves outcomes.
Stopping the TB Epidemic
Eliminating TB worldwide requires comprehensive strategies like:
Bacillus Calmette-Gurin (BCG) Vaccination
The BCG vaccine protects against disseminated TB in children. Immunity wanes by adulthood but helps prevent severe disease.
Targeted Testing and Treatment
Focusing detection and effective treatment in at-risk populations and places with higher TB rates restricts spread and resistance.
Airborne Infection Controls
Healthcare facilities use special ventilation to isolate those with suspected TB. This reduces nosocomial outbreaks to protect wider public health.
FAQs
How does someone get infected with TB?
TB is an airborne disease. You can get infected by inhaling TB bacteria suspended in the air, usually by spending prolonged time exposed to someone with active pulmonary TB who coughs or sneezes. Less commonly, you can get TB from bacteria that spreads to other body parts.
What’s the difference between latent TB and active TB disease?
Those with latent TB are infected with TB bacteria but don’t show symptoms and aren’t contagious. About 10% reactivate later as active disease. Active TB causes chronic cough, fever, chest pain and other symptoms from multiplying bacteria.
Why does multidrug-resistant TB develop?
TB bacteria can mutate over time and evolve the ability to “resist” and survive standard antibiotics. This leads to multidrug-resistant strains that require intensive, costly specialty antibiotic regimens lasting up to 2 years to treat.
What are the most effective ways to stop the global TB epidemic?
Strategies to curb TB transmission focus on vaccination, targeted testing/treatment of at-risk groups, and improved airborne infection controls in healthcare settings. But better funding for TB research to improve diagnostics, medicines and patient care is vital.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.
Add Comment