TUBERCULOSIS, MODE OF TRANSMISSION, DIAGNOSIS, TREATMENT AND PREVENTIONS

INTRODUCTION

TB is an airborne disease caused by the bacterium Mycobacterium tuberculosis. In ancient times it was also known as “Consumers” and also known as “White Plague’’. The bacteria usually attack the lungs but can also attack on any part of the body such as kidneys and spine.

TYPES OF TUBERCULOSIS

Pulmonary Tuberculosis: The most common symptom in tuberculosis of the lung is fever. It can be a low-grade fever which rarely crosses 100°F. Productive cough is the main symptom of this type of TB.
Brain Tuberculosis: This is also called as tuberculous meningitis or TB meningitis. Patients mostly experience variable degrees of headache and if it is not treated properly then it may slip to coma.
Pleural Tuberculosis: If tuberculosis affects the lining of the lungs then it causes the accumulation of fluids called as pleural effusions. Then it makes difficulty for lungs to expand resulting in making individuals breathless.
Bladder or Kidney Tuberculosis: It leads to condition called as TB Cystitis and there is a presence of pus in the urine with a burning sensation.
Skeletal Tuberculosis: In this the bacteria affect the spinal column and it is also called as Pott’s disease. It Primarily show pain along spine and causes spasm which can lead to back stiffness.
GI Tract Tuberculosis: It can affect the way from food pipe to the last part of intestine and it can lead to difficulty in swallowing, diarrhea and stomach ulcers.
Miliary Tuberculosis: It is the type of TB that occurs when the bacteria spread through the bloodstream, affecting multiple organs throughout the body.

TRANSMISSION OF TUBERCULOSIS

Infectious particles generate when person who have pulmonary or laryngeal TB disease cough, sneeze, shout or sing.
Transmission occurs when a person inhales droplet containing the microbe and the droplet nuclei traverse the mouth or nasal passage then the upper respiratory tract, and bronchi to reach the alveoli of the lungs.

FACTORS INVOLVES IN THE SPREAD OF DISEASE

Malnutrition
Diabetes
Moist environment
Poor living conditions
Bad sanitary
Alcohol
Tobacco smoke

SYMPTOMS

The general symptoms include:

Bad cough that lasts three weeks or longer
Weakness or fatigue
Weight loss
Loss of appetite
Chills
Fever
Sweating at night.

In case of Extrapulmonary Tuberculosis, the symptoms include:

Lymphadenopathy
Abdominal pain
Joint or bone ache
Persistent headache
Seizures
Neurologic deficit
Cutaneous lesions

INCIDENCE

Worldwide, TB is one of the top 10 causes of death and the leading cause from a single infectious agent. In 2019, an estimated 10 million people fell ill with TB worldwide which include 5.6 million men, 3.2 million women and 1.2 million children. TB is present among all countries and all age groups.

EPIDEMIOLOGY

In Pakistan TB is a highly epidemic. According to the latest WHO estimations, the incidence, prevalence and mortality of TB in Pakistan are 230 per 100000, 310 per 100000 and 39 per 100000, respectively. This indicates 410,000 incident cases of TB and 69,000 TB deaths in Pakistan every year. Pakistan, with an estimated 510,000 new TB cases emerging each year and approximately 15,000 developing drug-resistant TB cases every year. It is ranked fifth among the highest TB burden countries worldwide. The country is also estimated to have the fourth highest multidrug-resistant TB (MDR-TB) prevalence globally.

PATHOGENESIS

Infection begins with dispersion of aerosols from cough of TB patient. In the lung of the patient, the bacilli are phagocytosed by alveolar macrophages, which then invade the underlying epithelium. A small number may multiply intracellularly and are released when the macrophages die. If alive, then they may spread to lymphatic channels or through blood stream to areas where TB can develop.

DIAGNOSIS

Tuberculin Test: A small amount of a substance called tuberculin is injected just below the skin on the inside of the forearm. A hard, raised red bump means it likely to have TB infection.
Blood Tests: Blood tests can confirm latent or active tuberculosis.
Imaging Tests: If anyone had a positive skin test, then a chest X-ray or a CT scan is recommended. This shows white spots in your lungs that shows changings made by bacteria.
Sputum Test: If the chest X-ray shows signs of tuberculosis, the doctor might take samples of your sputum. Sputum Analysis also shows drug-resistance of MTB. So helps the doctor to choose the right medication.
Fluorescent Electron Microscopy: Florescent Microscopy in the diagnosis of tuberculosis is a priority, useful when few bacilli are present as it increases the sensitivity in HIV patients with tuberculosis.
GeneXpert: It is an amplification test that can rapidly diagnose tuberculosis and detect rifampicin resistance.

PREVENTION

TB infection control including the use of masks & respirators, which means preventing the transmission of TB.
The pasteurization of milk also helps to prevent humans from getting bovine TB.

TREATMENTS

First Line Drugs are:

Isoniazid
Ethambutol
Rifampin
Pyrazinamide

Second Line Drugs are:

Ciprofloxacin
Amikacin
Moxifloxacin
Streptomycin

VACCINE

The vaccination used for the TB is Bacillus Calmette-Guerin (BCG) where it is a part of national childhood immunization program and mostly administered in infant after birth.

CONCLUSION

TB is an airborne disease caused by the bacterium which mainly attack the lungs and spreads through the aerosols when patient with active TB coughs, sneezes, speaks, or sings. Bad cough that lasts three weeks or longer and weight loss are the main symptoms of TB. However, it can be diagnosed on the basis of number of tests and can be treated with antibiotics if taken in recommended dose and for recommended duration. Overall, tuberculosis is a curable disease, but it can still be dangerous globally.

FAQs

When was TB discovered?

On March 24, 1882, Robert Koch discovered the cause of tuberculosis.

Is TB curable?

Yes, TB is curable with antibiotics.

How is TB spread?

TB spreads through the air when someone with active TB coughs, sneezes, speaks, or sings.

What should I avoid if I have TB?

The patient should limit refined grains and sugary drinks. As refined grains are low in fiber and can cause blood sugar spikes and sugary drinks can weaken the immune system.