Tuberculosis

Description

Commonly called TB, is a contagious (spreadable) infection that typically attacks lungs. And may spread to other parts of the body like your brain & spine. In 20^th century, tuberculosis was the leading cause of death. Nowadays, most of its cases are treated successfully with antibiotics. It can take a long time i.e. at least 6 to 9 months, before you are completely cured.

TB is caused by a bacterium that will attack your body & destroys tissue. In lungs, it may actually create a hole. Most people don’t show any symptoms called latent tuberculosis, as body’s immune system keeps them from spreading and only about 10% of latent infections develop into active TB which should be immediately treated. If active cases are left untreated they lead to death.

Causes

Tuberculosis spreads through the air. Breathing the air of an infected person is what causes the infection. However, this only happens when a lot of time is spend with someone who has it.

Risk factors

There are a number of factors that prove to be a risk & make you more susceptible towards catching TB infection.

RISK OF ACTIVE DISEASE:

Most common factor known is that of HIV (human immunodeficiency virus) and about 13% of those with HIV also develop TB.
Those who are infected with tuberculosis (latent type), develop into active cases.
Use of certain medicines like corticosteroids & infliximab (anti-alpha TNF monoclonal antibody) is another risk in developed world.
Diabetes mellitus (there is 3 fold increased risk)
Silicosis i.e. form of occupational lung disease (30-fold increased risk)
Tobacco smoking (2-fold increased risk)
Indoor air pollution
Malnutrition (diet lacking healthy amount of nutrients)
Young-age
Recreational drug use (chemical substances taken for enjoyment & leisure purpose)
Severe kidney disease
Head & neck cancer
Organ transplant
Genetic susceptibility

INFECTION SUSCEPTIBILITY:

If you have come are in contact with people having TB.
Babies and children have higher chances as their immune system is not properly developed.
Tobacco smoking

Symptoms

The following symptoms may occur:

A cough that lasts more than 3 weeks
Fever, chills, and weakness
Feeling breathless
Coughing blood
Sweating at night
Weakness and weight loss, along with a loss of appetite.

Diagnosis

Its diagnosis varies in both type of TB.

ACTIVE TUBERCULOSIS:

Diagnosis of active TB based on just signs & symptoms can be difficult. However, diagnosis for T should be considered when there are signs of lung disease or constitutional symptoms lasting more than 2 weeks.
Initial evaluation includes a chest X-ray & multiple sputum cultures for acid-fast bacilli.
Interferon-y release assays & tuberculin skin tests (little use in developing countries)
Interferon gamma release assays (IGRA) has limitations in HIV.
Definitive diagnosis done by taking sputum, pus or tissue biopsy & performing culture test for identifying M. tuberculosis in it. But the organism is slowly-growing so it takes two to six weeks for results.

LATENT TUBERCULOSIS:

Mantoux tuberculin skin test is used to screen people at high risk of TB.
This test may be falsely negative if you are suffering from sarcoidosis, Hodgkin’s lymphoma, malnutrition or active tuberculosis.
Those who come positive to Mantoux test are commended Interferon-gamma release assays. IGRAs can be affected by M. szulgai, M. marinum, and M. kansasii.
It is recommended by USPSTF to screen people who are at high risk for latent TB with tuberculin skin test or interferon-gamma release assay.

Management

The disease management or treatment involved for TB include antibiotics that will help the bacteria. It is difficult to provide effective TB treatment as chemical composition of mycobacterial cell wall (part of bacteria on which medicine acts) is unusual, that will hinder the entry of drugs & renders antibiotics ineffective.

In active TB, several antibiotic combinations are used in order to prevent bacteria from developing antibiotic resistance.
Latent TB is also treated with antibiotic combination & treatment takes 3 to 9 months to prevent it from progressing into active TB disease.
Education & counselling both can play a major role in improving completion rate of latent tuberculosis treatment.
Six-month treatment with anti-TB drug will result in higher success rate as compared to treatment which is less than 6 months.
In case of TB recurs, then testing to determine which antibiotic is sensitive to the treatment is important. If multiple-drug-resistant TB (MDR-TB) is detected, then treat with at least 4 effective antibiotics for a period of 18 to 24 months.
It is also recommended by WHO, that a health care provider watches the person taking the medicine, for reduction in number of people not taking antibiotics appropriately.