TUBERCULOSIS

INTRODUCTION  
Tuberculosis, or TB, is an infectious bacterial disease caused by Mycobacterium tuberculosis, which most commonly affects the lungs.
It is transmitted from person to person via droplets from the throat and lungs of people with the active respiratory disease.
In healthy people, infection with Mycobacterium tuberculosis often causes no symptoms, since the person's immune system acts to “wall off” the bacteria. The symptoms of active TB of the lung are coughing, sometimes with sputum or blood, chest pains, weakness, weight loss, fever and night sweats. Tuberculosis is treatable with a six-month course of antibiotics.

Symptoms

     Signs  of TB in the lungs may include

• A bad cough that lasts 3 weeks or longer
• Weight loss
• Coughing up blood or mucus
• Weakness or fatigue
• Fever and chills
• Night sweats
• have chest pain when you cough

• Excessive sweating, especially at night

Risk  for active TB:
The following people are at higher risk for active TB:

1. ·         Elderly
2. ·         Infants
3. ·         People with weakened immune systems, for example due to AIDS, chemotherapy, diabetes, or certain medications

Your risk of contracting TB increases if you:

1. ·         Are in frequent contact with people who have TB
2. ·         Have poor nutrition
3. ·         Live in crowded or unsanitary living conditions

The following factors may increase the rate of TB infection in a population:

1. ·         Increase in HIV infections
2. ·         Increase in number of homeless people (poor environment and nutrition)
3. ·         The appearance of drug-resistant strains of TB

In the United States, there are approximately 10 cases of TB per 100,000 people. However, rates vary dramatically by area of residence and socioeconomic status.

Transmission 

In the lung, the organism is taken up by alveolar macrophages and carried to lymph nodes, from where it may spread to multiple organs. Two to eight weeks after infection, cell mediated immunity (CMI) and hypersensitivity (DTH) develop leading to the characteristic reaction to the tuberculin test and, in immunocompetent individuals, containment of infection. Inflammatory immune responses eventually result in lung damage.

How is TB treated?

In many countries, vaccination against TB is routinely practised. The Bacillus Calmette-Guerin (BCG) vaccine is a live, attenuated strain of Mycobacterium bovis which was introduced in 1922. However, the true efficacy of BCG is unknown. Early clinical trials in Europe showed up to 80% protection, but more recent trials in India and Africa showed little value.

The first effective treatment for TB was developed in the 1940s - streptomycin.
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TB is currently treated by means of combination therapy, using cocktails of 3-4 drugs with different properties:

• Antibacterial activity: e.g. isoniazid, rifampin, streptomycin
• Inhibiting the development of resistance: e.g. isoniazid, rifampin, ethambutol

What are Mycobacteria?

Tuberculosis complex organisms are:

• Obligate aerobes growing most successfully in tissues with a high oxygen content, such as the lungs.
• Facultative intracellular pathogens usually infecting mononuclear phagocytes (e.g. macrophages).
• Slow-growing with a generation time of 12 to 18 hours (c.f. 20-30 minutes for Escherichia coli).
• Hydrophobic with a high lipid content in the cell wall. Because the cells are hydrophobic and tend to clump together, they are impermeable to the usual stains, e.g. Gram's stain.
• Known as "acid-fast bacilli" because of their lipid-rich cell walls, which are relatively impermeable to various basic dyes unless the dyes are combined with phenol. Once stained, the cells resist decolorization with acidified organic solvents and are therefore called "acid-fast". (Other bacteria which also contain mycolic acids, such as Nocardia, can also exhibit this feature.)

Signs and tests

The doctor or nurse will perform a physical exam. This may show:

• Clubbing of the fingers or toes (in people with advanced disease)
• Swollen or tender lymph nodes in the neck or other areas
• Fluid around a lung (pleural effusion)
• Unusual breath sounds (crackles)

Tests may include:

• Biopsy of the affected tissue (rare)
• Bronchoscopy
• Chest CT scan
• Chest x-ray
• Interferon-gamma blood test such as the QFT-Gold test to test for TB infection
• Sputum examination and cultures
• Thoracentesis
• Tuberculin skin test (also called a PPD tests)

        Complications

1. ·        Pulmonary TB can cause permanent lung damage if not treated early.
2. ·        Medicines used to treat TB may cause side effects, including liver problems. Other side effects include:
3. ·        Changes in vision
4. ·        Orange- or brown-colored tears and urine
5. ·        Rash

Disseminated tuberculosis

Disseminated tuberculosis (TB) is a contagious bacterial infection that has spread from the lungs to other parts of the body through the blood or lymph system.

Indications

he disease may also alter the results of the following tests:

·         Complete blood count (CBC)

·         Peripheral blood smear

·         Blood calcium level

Complications of disseminated TB

Complications of disseminated TB can include:

• Adult respiratory distress syndrome (ARDS)
• Liver inflammation 
• Lung failure
• Relapse of the disease

Medicines used to treat TB may cause side effects, including liver problems. Other side effects include:

• Changes in vision
• Orange- or brown-colored tears and urine
• Rash

A vision test may be done before treatment so your doctor can monitor any changes in your eyes' health over time.

The disease may also alter the results of the following tests:

• ·         Complete blood count (CBC)
• ·         Peripheral blood smear
• ·         Blood calcium level

Treatment

The goal of treatment is to cure the infection with drugs that fight the TB bacteria. Treatment of active pulmonary TB will always involve a combination of many drugs (usually four drugs). All of the drugs are continued until lab tests show which medicines work best.

The most commonly used drugs include:

• Isoniazid
• Rifampin
• Pyrazinamide
• Ethambutol

Other drugs that may be used to treat TB include:

• Amikacin
• Ethionamide
• Moxifloxacin
• Para-aminosalicylic acid
• Streptomycin

You may need to take many different pills at different times of the day for 6 months or longer. It is very important that you take the pills the way your health care provider instructed.

When people do not take their TB medications as recommended, the infection may become much more difficult to treat. The TB bacteria may become resistant to treatment, and sometimes, the drugs no longer help treat the infection.

When there is a concern that a patient may not take all the medication as directed, a health care provider may need to watch the person take the prescribed drugs. This is called directly observed therapy. In this case, drugs may be given 2 or 3 times per week, as prescribed by a doctor.

You may need to stay at home or be admitted to a hospital for 2 - 4 weeks to avoid spreading the disease to others until you are no longer contagious.

Your doctor or nurse is required by law to report your TB illness to the local health department. Your health care team will be sure that you receive the best care for your TB.

Tuberculosis and Pregnancy

Introduction

Untreated tuberculosis (TB) disease represents a greater hazard to a pregnant woman and her fetus than does its treatment. Treatment of pregnant women should be initiated whenever the probability of TB is moderate to high. Infants born to women with untreated TB may be of lower birth weight than those born to women without TB and, in rare circumstances the infant may be born with TB. Although the drugs used in the initial treatment regimen for TB cross the placenta, they do not appear to have harmful effects on the fetus.

Testing

The tuberculin skin test is considered both valid and safe to use throughout pregnancy. The TB blood test is safe to use during pregnancy, but has not been evaluated for diagnosing M. tuberculosis infection in pregnant women. Other tests are needed to show if a person has TB disease.

Treatment

Latent TB Infection (LTBI) – Isoniazid (INH)
( administered either daily or twice weekly for 9 months is the standard regimen for the treatment of LTBI in pregnant women). Women taking INH should also take pyridoxine (vitamin B6) supplementation.Caution: The 12-dose regimen of INH and Rifapentine (RPT) is NOT RECOMMENDED for pregnant women or women expecting to be pregnant within the next 3 months.

TB Disease –
            Treatment regimen :
 The preferred initial treatment regimen is 

•  INH,
•  rifampin (RIF), 
•  ethambutol (EMB) (daily for 2 months)

                         followed by INH and RIF daily, or twice weekly for 

                        7 months (for a total of 9 months of treatment).

                        Streptomycin should not be used because it has been 

                        shown to have harmful effects on the fetus. In most 

                        cases, pyrazinamide (PZA) is not recommended to be 

                        used because its effect on the fetus is unknown.

HIV Infection :

. TB treatment regimens for HIV-infected pregnant women should include a rifamycin. Although the routine use of PZA during pregnancy is not recommended in the United States, the benefits of a TB treatment regimen that includes PZA for HIV-infected pregnant women may outweigh the undetermined potential risks to the fetus.

Contraindications

The following antituberculosis drugs are contraindicated in pregnant women:

• Streptomycin
• Kanamycin
• Amikacin
• Capreomycin
• Fluoroquinolones

Women who are being treated for drug-resistant TB should receive counseling concerning the risk to the fetus because of the known and unknown risks of second-line antituberculosis drugs.

Breastfeeding

• Breastfeeding should not be discouraged for women being treated with the first-line antituberculosis drugs( because the concentrations of these drugs in breast milk are too small to produce toxicity in the nursing newborn). 
• For the same reason, drugs in breast milk are not an effective treatment for TB disease or LTBI in a nursing infant.
•  Breastfeeding women taking INH should also take pyridoxine (vitamin B6) supplementation.

Patient advice:

• Advice the patient to sit in open enviornment.
• sit in area where there is necessary light 
• avoid siting in dark room as it gives strength to bacteria in growing ,making colonies.
•  Mantain dietry intake eat more n more apples,pomegranate,beet root.