Tuberculosis (TB)

Overview

Tuberculosis (TB) is an infectious disease primarily affecting the lungs, although it can also impact organs such as the spine, brain, or kidneys. It is caused by a type of bacteria that spreads through airborne droplets when an infected person coughs, sneezes, or sings. TB is more prevalent in crowded environments, and individuals with weakened immune systems, like those with HIV/AIDS, are at greater risk.

The infection progresses through three stages: primary infection, latent TB infection, and active TB disease. In its latent stage, the infection is dormant and the individual shows no symptoms, but the bacteria remain in the body. If it progresses to the active disease stage, the person becomes contagious and exhibits symptoms.

Treatment for TB involves a course of antibiotics, although some bacterial strains have developed resistance to conventional treatments, complicating recovery efforts.

Symptoms

A tuberculosis (TB) infection occurs when the bacteria from the disease continue to multiply in the lungs. There are three stages to a tuberculosis infection. Every stage has a particular set of symptoms.

  • Primary TB infection: During a primary infection, most people don’t experience any symptoms. Some persons may experience flu-like symptoms, including:
    • Cough.
    • Low grade fever.
    • Tiredness or fatigue.
  • Latent TB infection:  When a TB infection is latent, there are no symptoms.
  • Active TB disease: Active tuberculosis indications in the lungs often start off mildly and get worse over a few weeks. They could consist of:
    • Chest pain.
    • Coughing for more than 2 weeks.
    • Cough with blood or mucus.
    • Fever or chills.
    • Loss of appetite.
    • Night sweats.
    • Pain with breathing or coughing.
    • Tiredness or fatigue.
    • Weight loss.
  • Extrapulmonary TB: The body can get tuberculosis (TB) from the lungs and spread to other areas. The location of the infection on the body affects the symptoms. Typical symptoms might be:
    • Fever or chills.
    • Loss of appetite.
    • Night sweats.
    • Pain around the infection site.
    • Tiredness or fatigue.
    • Weight loss.

Although active tuberculosis disease in the voice box is not lung-related, its symptoms are more similar to lung disease. The common location of extrapulmonary TB includes the following:

    • Bones and joints.
    • Fluid around the brain and spinal cord.
    • Genitals.
    • Heart muscles.
    • Kidneys.
    • Larynx or voice box.
    • Liver.
    • Lymph nodes.
    • Skin.
    • Walls of blood vessels.
  • Children with active TB disease: When a child has active TB disease, the signs and symptoms might vary. Indications by age often include the following:
    • Infants: The infant doesn’t develop or put on weight as expected. Additionally, a newborn may have the following symptoms due to fluid swelling around the brain or spinal cord:
      • Being inactive or lethargic.
      • Being picky.
      • Bulging soft spot on the head.
      • Poor feeding.
      • Poor reflexes.
      • Vomiting.
    • 1- to 12-year-olds: Smaller children may experience weight loss and an unresponsive temperature.
    • Teenagers: The symptoms to teenagers are the same with the indicators for adults.

If your symptoms persist despite rest, it’s important to consult your healthcare provider. Additionally, seek urgent medical attention if you notice blood when coughing, or if blood appears in your urine or stool.

Causes

Tuberculosis is caused by a bacterium known as Mycobacterium tuberculosis. It primarily infects the lungs, though it can affect other parts of the body as well. The transmission of TB occurs through the air when people with active TB in the lungs or larynx (voice box) release bacteria-laden droplets. These droplets can be expelled during talking, singing, laughing, coughing, or sneezing. To contract TB, a person generally needs to inhale these droplets, which is more likely in crowded and enclosed spaces where people spend extended periods together.

  • Active TB: Individuals with active TB can spread the bacteria to others. After 2 to 3 weeks of appropriate treatment, however, they usually can’t transmit the disease.
  • Latent TB: Those with latent TB infection carry the bacteria but do not exhibit symptoms and cannot spread the infection to others.

Drug-resistant tuberculosis

Drug-resistant TB occurs when the bacteria develop resistance to the antimicrobial drugs used to treat the infection. This resistance can arise due to natural genetic variations that allow some bacteria to survive antibiotic treatment. If these bacteria are not completely killed by the treatment, they can multiply and pass on their resistant traits. Common causes for the emergence of drug-resistant TB include improper use of antibiotics, discontinuation of treatment, poor drug quality, incorrect drug prescriptions, and issues with drug absorption in the body.

Understanding the transmission and resistance mechanisms of TB is crucial for effective control and treatment strategies.

Risk factors

Although anybody may contract TB, there are several things that make it more likely to happen. An infection’s potential to develop into active tuberculosis disease is increased by additional factors. A TB test is advised for those who are at a higher risk of contracting the disease or who are currently sick with TB. If any of the following risk factors apply to you, speak with your healthcare provider.

It is simpler for the disease to spread among people in certain living or working environments. The following circumstances raise the chance of contracting tuberculosis:

  • Residing with a person who has an active TB disease.
  • Residing or visiting a country where tuberculosis is common, such as the Pacific Islands, Asia, Africa, and various Latin American and African nations.
  • Residing or work in highly populated environments, such as correctional facilities, nursing homes, and homeless shelters.
  • Residing in an area where TB infection is considered to be highly common.
  • Providing medical care and managing patients who have a high risk of tuberculosis.
  • Risk for active TB disease: The possibility of a tuberculosis infection developing into active TB disease is higher in those with compromised immune systems. The following diseases or treatments compromise immunity:
    • Cancers of the blood, head, and, neck.
    • Chemotherapy.
    • Diabetes.
    • HIV/AIDS.
    • Long-term use of prescription steroids.
    • Medication to stop transplant organ rejection.
    • Over alcohol consumption.
    • Severe kidney disease.
    • Underweight or malnutrition.
    • Using illegal injection drugs.
    • Using tobacco products and smoking.
  • Age and active TB disease: The possibility of having an active TB disease as you age:
    • Less than 5 years old: Children have a significant risk of developing an active TB infection until they become five years old. Children under the age of two are more at risk. In this age range, meningitis—a dangerous condition of the fluid around the brain and spinal column—is frequently the result of tuberculosis.
    • 15 to 25 years old: This age group is more likely to experience more severe active TB disease in the lungs.
    • 65 and older: Age causes a decrease in the immune system. Active TB disease is more common in older persons. It could also be more challenging to treat the medical condition.