Tuberculosis: Symptoms, Contagion, Diagnosis, and Treatment

Tuberculosis (TB): Symptoms, Transmission, Diagnosis, and Treatment

Tuberculosis is a respiratory infectious disease that remains common in Thailand. Many people misunderstand it as a hereditary disease or an incurable illness. In reality, tuberculosis is curable if detected early and medication is taken continuously as prescribed by a doctor. This article gathers essential information about tuberculosis, from its causes and symptoms to diagnosis, treatment, and prevention.

What is Tuberculosis?

Tuberculosis is not a hereditary disease; it is a contagious disease caused by a bacterium named Mycobacterium tuberculosis. This bacterium is rod-shaped and extremely small, invisible to the naked eye, requiring special staining methods and examination under a microscope to be seen.

TB bacteria can affect almost any part of the body, such as the intestines, kidneys, bones, skin, lymph nodes, and meninges. However, the most common location and the largest public health concern is pulmonary tuberculosis (TB in the lungs).

How is Tuberculosis Transmitted?

Tuberculosis spreads from person to person through the respiratory system. When a patient with bacteria in their sputum talks, coughs, or sneezes without covering their mouth, TB bacteria float out in sputum droplets. Larger droplets settle onto surfaces, while smaller droplets float in the air. People who inhale these droplets are at risk of infection.

However, not everyone who becomes infected will develop active tuberculosis because the body has multiple mechanisms to fight and control the bacteria. Only about 10% of infected individuals develop active TB disease.

How long does TB bacteria survive in the environment?

• In the air without sunlight, the bacteria can survive for 8–10 days.
• Sunlight destroys the bacteria within 5 minutes.
• Boiling water destroys the bacteria within 2 minutes.

Therefore, disposing of a patient's sputum should involve heat, such as burning, to completely eliminate the bacteria.

Symptoms of Pulmonary Tuberculosis

Key symptoms of pulmonary tuberculosis to watch for include:

• Coughing persistently for more than 2 weeks
• Dry cough, cough with phlegm, or coughing up blood-tinged sputum
• Chest pain, shortness of breath
• Low-grade fever in the late afternoon or evening
• Loss of appetite, weight loss, fatigue
• Unusual night sweats

These symptoms develop gradually and resemble common respiratory illnesses, so many patients delay seeking care until the infection spreads. If you have a chronic cough combined with weight loss, you should be evaluated promptly.

Who is at Risk for Tuberculosis?

• People living with untreated TB patients, such as household members or coworkers
• People living with HIV or AIDS patients
• Patients with chronic conditions such as diabetes, liver disease, or kidney disease
• Individuals on long-term immunosuppressive medications, such as steroids
• People living or working in continuously air-conditioned environments with poor ventilation, or in crowded communities
• Smokers, alcohol drinkers, or substance users
• Healthcare personnel caring for tuberculosis patients

When Should You Get Screened for TB?

You should get tested for tuberculosis if you experience the following:

• Coughing persistently for more than 2 weeks
• Low-grade fever in the late afternoon or evening
• Loss of appetite, weight loss, fatigue
• Abnormally heavy night sweats
• Having a relative or close contact diagnosed with pulmonary tuberculosis

For individuals without symptoms, regular annual health checkups are recommended. For immunocompromised individuals or those taking immunosuppressants—such as diabetic patients, substance users, or HIV-infected individuals—doctors may recommend more frequent screenings every 3–6 months.

Diagnosis of Tuberculosis

Microscopic Sputum Examination

This is a definitive method to confirm pulmonary tuberculosis because the bacteria in the sputum can be observed directly. Doctors typically collect two sputum samples to increase diagnostic accuracy.

Chest X-ray

Helps visualize lesions in the lungs; however, an X-ray alone cannot confirm tuberculosis and must always be combined with sputum testing.

Tuberculosis Culture

Used when doctors suspect TB but initial sputum smears are negative. This method provides high accuracy and can also identify drug-resistant strains, though it takes longer to yield results than other methods.

Treatment of Tuberculosis: Is It Truly Curable?

Tuberculosis is curable. Highly effective anti-TB medications are available today. If patients take their medication consistently and regularly, treatment takes only 6–8 months (compared to 1.5 to 2 years in the past).

The key to treatment is consistency. Incorrect treatment, missing doses, or failing to complete the course leads to drug-resistant tuberculosis, which is much harder to treat, requires longer treatment, and allows patients to transmit drug-resistant strains to others.

DOT: Directly Observed Treatment

DOT (Directly Observed Treatment) involves a designated treatment supporter overseeing the patient's care with the following responsibilities:

• Observing and supervising the patient taking their medication, and recording every dose
• Encouraging the patient to complete the prescribed treatment duration
• Advising on self-care during treatment and offering guidance if side effects or allergic reactions occur
• Reinforcing healthy habits, such as avoiding alcohol and smoking
• Maintaining patient confidentiality and not disclosing treatment details to others
• Reporting patient information to doctors or public health officers, including medication adherence, general condition, and issues encountered during treatment

Supporters should have a basic understanding of TB, including symptoms, transmission, treatment protocols, and prevention.

Signs That Treatment is Working

• Decreased coughing
• Reduction in fever
• Weight gain

Can You Stop Medication When Symptoms Improve?

Never stop medication on your own. TB patients will still have lesions and remaining bacteria in their lungs. Even if symptoms improve within 2 weeks after starting medication, the bacteria in the lungs are not completely gone. Stopping treatment early or missing doses can lead to drug resistance, making it harder to treat or even incurable. Medication must be continued until a doctor instructs you to stop.

Side Effects of Anti-Tuberculosis Medications

Mild Side Effects

Mild rash, loss of appetite, nausea, vomiting, numbness in hands and feet, joint pain. Most are not dangerous; doctors will provide symptomatic treatment while patients continue taking their TB medication.

Severe Side Effects (Stop Medication and See a Doctor Immediately)

Severe raised red rash over the entire body, hearing loss or ringing in the ears, unsteadiness when walking, jaundice (yellow skin and eyes due to hepatitis), blurred vision, confusion, or psychiatric symptoms such as depression.

How to Care for Yourself During Illness and Treatment

• Take prescribed medications in the exact type and dosage specified by your doctor consistently, and attend all follow-up appointments until instructed to stop.
• Symptoms will improve after about 2 weeks of medication, but do not stop taking it, as this can cause drug resistance.
• Cover your mouth and nose with a tissue or cloth whenever you cough or sneeze to prevent spreading the infection.
• Avoid alcohol, tobacco, and all addictive substances.
• Spit phlegm into a covered container or cup, then dispose of it in a toilet, bury it, or burn it.
• Maintain a well-ventilated living space exposed to sunlight, and air bedding out in the sun regularly.
• Eat a well-balanced, nutritious diet and get adequate rest.
• Have household contacts and close relations, especially young children, evaluated at a hospital or health center.

How Tuberculosis and HIV Are Related

• HIV infection weakens the immune system, causing infected individuals to develop active TB faster and more severely than non-HIV-infected individuals.
• Tuberculosis is an opportunistic infection that serves as the leading cause of death among AIDS patients.
• HIV-infected individuals who develop TB have a higher mortality rate than those who do not develop TB.

For these reasons, people living with HIV should undergo regular tuberculosis screening as advised by their physician.

Tuberculosis Prevention

• Get an annual health checkup and chest X-ray at least once a year.
• Ensure newborns receive the BCG vaccine at a hospital or nearby public health service center.
• If suspicious symptoms occur, seek medical evaluation immediately.
• Maintain good health through regular exercise and a nutritious diet.
• Avoid high-risk behaviors for HIV infection, which weakens immunity and increases vulnerability to TB.
• Avoid overcrowded, poorly ventilated spaces.
• Young children and the elderly should avoid close contact with active TB patients.
• If someone in your home has TB, support them in taking their medication consistently until the full treatment course is completed.

Frequently Asked Questions About Tuberculosis

Is tuberculosis a hereditary disease? No. Tuberculosis is a bacterial infection and is not passed down genetically.

Can tuberculosis be completely cured? Yes, it can be cured completely if medication is taken as prescribed for the full 6–8 month duration.

Does everyone infected with TB bacteria get sick? No. Only about 10% of infected individuals develop active tuberculosis disease.

What should you do if you live with a TB patient? Get screened, especially young children and immunocompromised individuals, and ensure the home is well-ventilated and exposed to sunlight.

Consult a Medical Specialist

Internal Medicine Center, G Floor, Piyavate Hospital Building. Open daily, Monday – Sunday, 08:00 – 19:00. Tel. 061-397-9275