Tuberculosis (TB) is a chronic infectious disease caused by the bacterium Mycobacterium tuberculosis, primarily affecting the lungs but can also involve other organs. This disease has high transmissibility and public health significance globally, posing a greater threat in resource-limited areas. According to data from the World Health Organization, millions of people are affected by this disease each year, highlighting the urgency of prevention and control efforts.
Tuberculosis can be categorized into two forms: "latent infection" and "active infection." Individuals with latent infections do not exhibit symptoms and are not contagious, but they may progress to active cases when their immune system weakens. Active tuberculosis causes noticeable symptoms and can be transmitted to others through respiratory droplets. Understanding its transmission routes, diagnostic methods, and treatment principles is crucial for controlling the spread of the disease.
Modern medicine has developed various diagnostic techniques and treatment regimens, but patient adherence and drug resistance remain challenges. Vaccination, public health monitoring, and early treatment are core strategies for controlling tuberculosis. The following sections will comprehensively analyze this globally concerning infectious disease from multiple aspects, including causes, symptoms, diagnosis, treatment, and prevention.
The pathogen of tuberculosis is Mycobacterium tuberculosis, primarily transmitted through airborne droplets. When an infected person coughs, sneezes, or talks, droplets containing the bacteria can remain suspended in the air, and those who come into contact may inhale them and become infected. Whether an infection develops into active tuberculosis depends on the strength of the individual's immune system.
Risk factors include:
It is noteworthy that although latent infection carriers are not contagious, if their immunity sharply declines (such as during chemotherapy or HIV infection), they may progress to active cases within 10 years. Managing this latent state is a crucial aspect of preventing the spread of the epidemic.
Typical symptoms of active tuberculosis include a persistent cough lasting more than three weeks, coughing up blood or blood-streaked sputum, unexplained weight loss, persistent fever, and night sweats. These symptoms may be mistaken for common respiratory infections, leading to delayed diagnosis. Some patients may also experience fatigue and loss of appetite, which are non-specific symptoms that can easily be overlooked.
When tuberculosis bacteria invade organs outside the lungs, symptoms may vary depending on the site of infection:
Latent infection carriers typically have no symptoms but need to be identified through skin tests or blood tests. The severity of symptoms is closely related to the patient's immune status, with children and immunocompromised patients potentially presenting atypical symptoms, necessitating heightened vigilance.
Diagnosing tuberculosis requires a combination of clinical symptoms, imaging studies, and microbiological evidence. A chest X-ray is typically performed first, as active pulmonary tuberculosis often shows specific lesions such as upper lobe shadows or cavity formation. Sputum culture is the gold standard but requires 2-6 weeks of incubation time; modern molecular diagnostic techniques like GeneXpert can reduce this to a few hours.
Skin tests (Tuberculin skin test, TST) and interferon-gamma release assays (IGRA) are used to screen for latent infections. Suspected cases require detailed interviews, including exposure history, travel history, and immune status assessment. For suspected extrapulmonary tuberculosis patients, tissue biopsy, cerebrospinal fluid examination, or computed tomography scans may be necessary.
The diagnostic process must differentiate active tuberculosis from other similar respiratory diseases, such as lung cancer or pneumonia. Confirming multidrug-resistant tuberculosis (MDR-TB) requires drug sensitivity testing, which will influence the choice of treatment regimen. The application of new molecular diagnostic technologies has significantly improved the speed and accuracy of diagnosis.
Treatment for tuberculosis follows the principle of "multi-drug therapy," typically requiring more than 6 months of medication. The standard regimen includes a four-drug combination of isoniazid, rifampicin, pyrazinamide, and ethambutol, with all four drugs used for the first two months, followed by core medications for the next four months. This regimen effectively prevents the development of drug resistance.
Treatment for multidrug-resistant tuberculosis (MDR-TB) is more complex, requiring second-line drugs such as kanamycin and moxifloxacin, with treatment duration potentially extending to 18-24 months. The treatment process must strictly monitor drug side effects, such as hepatotoxicity, optic neuritis, or peripheral neuropathy, and dosage adjustments may be necessary.
Directly Observed Therapy (DOT) is a key strategy to ensure patient adherence to medication, with healthcare providers witnessing each dose taken. The success rate of treatment is highly correlated with patient compliance, and treatment interruption may lead to drug resistance. In recent years, the application of genetic testing technologies has also promoted the development of personalized treatment regimens.
The Bacillus Calmette-Guérin (BCG) vaccine is the primary preventive measure, routinely administered to infants in high-incidence countries. Vaccination can reduce the risk of severe tuberculosis (such as meningitis), but its protective effect against adult pulmonary tuberculosis is limited.
Public health measures include:
Personal protective measures include:
Seek medical attention immediately if you experience the following:
Individuals with high-risk factors (such as HIV infection, contact with confirmed patients, or undergoing immunosuppressive therapy) should also seek medical attention early if they experience mild respiratory symptoms. Early diagnosis can reduce transmission risk and improve treatment success rates. Healthcare institutions offer free screening services, encouraging suspected cases to seek medical care proactively.
Special populations such as healthcare workers and long-term care facility employees should undergo regular tuberculosis screening. Vulnerable groups such as pregnant women, children, or the elderly should be particularly vigilant when symptoms arise, as these patients may present atypical symptoms.
The standard treatment regimen for pulmonary tuberculosis usually lasts 6 to 9 months, depending on the type of infection and the patient's condition. If the full course is not completed, the bacteria may not be completely eradicated, leading to a relapse or the development of drug resistance, evolving into more difficult-to-treat "drug-resistant tuberculosis." Therefore, patients must follow their physician's instructions, attend regular follow-ups, and complete the entire treatment course.
How can the symptoms of pulmonary tuberculosis be distinguished from those of a common cold?Typical symptoms of pulmonary tuberculosis include a persistent dry cough lasting more than 2 weeks, coughing up blood, unexplained weight loss, and night sweats, while cold symptoms usually resolve within 1-2 weeks without long-term weight changes. If symptoms persist or recur, immediate medical attention should be sought for professional examination, such as sputum culture or chest X-ray.
Does vaccination with the BCG vaccine completely prevent infection with pulmonary tuberculosis?The BCG vaccine can reduce the risk of severe pulmonary tuberculosis (such as meningitis), but it does not provide 100% protection against infection. The vaccine's efficacy varies among individuals, and personal hygiene should still be observed post-vaccination, such as avoiding contact with patients and ensuring good air circulation. High-risk groups (such as healthcare workers or family members of patients) should still undergo regular health checks.
What should pulmonary tuberculosis patients pay attention to in their daily lives?Patients should wear masks to avoid infecting others, cover their mouth and nose with tissues or their elbow when coughing, and use separate utensils that are regularly disinfected. Living environments should be kept well-ventilated, and gatherings in closed spaces should be avoided. Additionally, maintaining a regular routine and balanced diet can enhance immunity and aid in recovery.
How does the treatment of drug-resistant tuberculosis differ from that of regular tuberculosis?Treatment for drug-resistant tuberculosis requires the use of second-line anti-tuberculosis drugs, with treatment duration potentially extending beyond 18 months, and side effects can be more pronounced (such as liver damage and hearing impairment). During treatment, strict monitoring of bodily responses is necessary, and adjustments to the treatment plan should be made in consultation with the physician. Preventing drug resistance is crucial, and patients should avoid self-discontinuing or interrupting their medication.
%201.svg)
Copyright © 2025 MedFrontiers. All Rights Reserved.
