When the Student Has Finished This Module, He Or She Will Be Able To

TUBERCULOSIS

INTRODUCTION

Tuberculosis is an infectious disease caused by a bacterium, myobacterium tuberculosis. The disease is spread when people inhale droplets of saliva or mucous from infected people. The droplets contain the tuberculosis bacterium and they become airborne when people with tuberculosis in their respiratory tract talk, sneeze, cough, and exhale. Tuberculosis primarily affects the lungs, but the tuberculosis bacteria can also infect and damage the spine, the liver, the eyes, the bones, the nervous system (brain and spinal cord), the skin, the bladder, and the gastrointestinal tract.

Tuberculosis is very common worldwide, but cases of tuberculosis are unusual in the United States. It is very contagious. However, the majority of people who are infected with tuberculosis never develop signs and symptoms of the disease. If tuberculosis is detected early and remains in the lungs, the available treatment is very effective.

OBJECTIVES

When the student has finished this module, he or she will be able to:

1. Identify a basic definition of tuberculosis.

2. Identify the way tuberculosis is spread.

3. Identify the organ that is most commonly affected by tuberculosis.

4. Identify two precautions that must be used when caring for a patient with tuberculosis.

TUBERCULOSIS: THE SCOPE OF THE PROBLEM AND ITS CAUSES

Tuberculosis has afflicted mankind for centuries: Egyptian mummies from 2400 BC have been found to have evidence of tuberculosis infections. There have been significant advances made in treating and preventing tuberculosis, but it is still a serious public health problem in many parts of the world. Approximately 9 million people are infected each year and approximately 3 million die each year from the disease. Fortunately, infection and death from tuberculosis in the United States is uncommon and the numbers have been decreasing every year since the 1950s.

Learning Break: Tuberculosis has become uncommon in the United States, but as a Certified Nursing Assistant, you should remember that the rate of infection with tuberculosis is definitely higher among health care workers.

As mentioned previously, tuberculosis is spread by inhalation of infected droplets that contain the tuberculosis bacterium. The droplets are extremely small (about 20,000 or so would fit in an inch) and once they are released, they stay airborne in the environment for a long period of time. Because of this, tuberculosis can be easily contracted if there are infected droplets in small enclosed areas, high concentration of the droplets, or if there are droplets in an area with poor ventilation.

After they are inhaled, the bacteria move into the deep parts of the lungs. Once there, a) they may be killed by the immune system, b) they can multiply and cause the disease, c) they can be isolated by the body and remain dormant but potentially active, or d) they can become active after a dormant period and cause the active disease. A and C are the most common scenarios.

Learning Break: Because tuberculosis is spread by inhaling the bacteria, people who live closely together in crowded conditions are more likely to contract tuberculosis. Poor sanitation and poor ventilation can also contribute.

Tuberculosis infection is more likely to occur in the elderly, people with alcohol or substance abuse problems, and people who are malnourished. People with a compromised immune system such as people infected with HIV, someone who is receiving chemotherapy, patients who are on long-term steroid therapy, or people who have had an organ transplant (these people are often taking medications that lower their immune function) are also more likely to contract tuberculosis. Men appear to be more likely to contract tuberculosis than women. There are no ethnic risk factors that increase the chances of being infected and developing the disease, but tuberculosis is more common in disadvantaged socio-economic groups.

Learning Break: The biggest risk factor for developing a tuberculosis infection is a compromised immune system, and the biggest risk for having the infection progress to the disease is a concurrent infection with HIV.

SIGNS AND SYMPTOMS OF TUBERCULOSIS

The great majority – about 90% – of people infected with tuberculosis never develops the active disease, and most of those that do get an active, symptomatic infection are elderly or have a compromised immune system. Almost always, the immune system contains the bacteria by walling it off and rendering it harmless. The bacteria stay dormant in the lungs and unless the person is tested, no one knows.

The only evidence that these people have been exposed is a positive response to a tuberculin skin test. The tuberculin skin test (TST) involves injecting a very small amount of inactive parts of the tuberculosis bacterium, just below the surface of the skin on the forearm. The injection site is examined in 48 to 72 hours and if there is an area of swelling more than 5 millimeters (about 1/8th of an inch), the test is considered to be positive and the person has been exposed.

Learning Break: The TST uses inactive parts of the tuberculosis bacterium. There is no risk of developing tuberculosis from receiving a TST injection. The TST is considered safe to use in women who are pregnant.

A positive response to the TST only means someone has been exposed to tuberculosis: they could have the active disease but more likely they do not. However, people with a positive TST who do not have the active disease are not infectious. However, the patient may be more likely to have the active disease if the area of swelling is greater than 5 millimeters and they have risk factors (HIV infection, chronic steroid use, etc.) or have recently been in close contact with someone who has the active disease.

The TST is not perfect. Some people can have the bacterium and the test will be negative, and some people who do not have the bacterium can have a positive test.

Learning Break: People who have the tuberculosis bacterium in their bodies but have walled it off and do not have the active disease are said to have latent tuberculosis.

People who have the active disease – the pulmonary form – typically develop the following signs and symptoms:

Productive cough: A productive cough – opposed to a dry cough – is a cough that is accompanied by large amounts of sputum or blood. (Note sputum is different than mucous. Mucous is generally thin, clear, and watery. Sputum is thick, often green or yellow in color, and viscous. Mucous in the respiratory tract is normal; sputum in the respiratory tract often indicates that someone has an infection)
Fever
Chest pain
Night sweats: The patient will wake up and find they are sweating profusely.
Lack of energy
Weight loss

Of course, these signs and symptoms can be caused by many other diseases and illnesses. In order to be sure someone has tuberculosis, samples of sputum must be checked, a TST must be done, and a chest x-ray must be performed. There is also a specific blood test that can be done.

Some people who have been infected with tuberculosis and develop the disease may get tuberculosis in some place other than the lung. These forms of tuberculosis are seldom seen. They are more common in patients with HIV infection, and a complete cure of one of these forms of tuberculosis is much less likely than a cure of the pulmonary form.

DRUG RESISTANT TUBERCULOSIS

In the early 1990s, people caring for patient with tuberculosis began to notice that there was growing percentage of cases that did not respond to the traditional drug therapy. Drug-resistant tuberculosis has been a growing problem since that time. There are two types of drug-resistant tuberculosis:

Multi-drug-resistant tuberculosis: The bacteria that cause this form of the disease cannot be killed by the two most powerful drugs available, isoniazid and rifampin. This type of tuberculosis can be treated. However the treatment protocol is long (two years), the drugs that are effective are expensive, and they have serious, unpleasant side effects.
Extensive drug-resistant tuberculosis: Fortunately, this type of tuberculosis is uncommon (only 49 cases were been reported in the United States between 1993 and 2006) because it is very difficult to treat. None of the standard medications work, and the second-line drugs that can help someone with multi-drug resistant tuberculosis do not work, either. Like multi-drug resistant tuberculosis, treating extensive drug-resistant tuberculosis is a lengthy process with serious, unpleasant side effects.

TAKING CARE OF THE PATIENT WITH TUBERCULOSIS

When you are working with a patient with tuberculosis, there are three areas of care that you should focus on: infection control, social support and nutrition, and drug therapy.

Infection Control

People who have been diagnosed with active tuberculosis are infectious. Also, people with the active disease can infect other people even if the infected person does not have signs and symptoms. The risk of infection depends on how long and how close the contact is and the concentration of the bacterium in the airborne droplets.

Patients with a diagnosis of tuberculosis must be in a private room with proper ventilation and a proper air exchange system; the tuberculosis bacterium can remain in the air for several hours. As a health care professional, you must understand how to protect yourself. You must also understand how to prevent the spread of the disease. The precautions you need to take are not complicated, but they must be followed very carefully and consistently.

Everyone entering the room for any amount of time must wear a mask or a respirator. The infectious disease department of the facility you work at will determine which type of mask or respirator is appropriate. An ordinary paper mask is not sufficient. They cannot filter out the tiny infected droplets and they don’t provide a proper seal.
Instruct the patient to cover his/her nose and mouth when coughing or sneezing.
Use standard, universal precautions. Wash your hands before entering the room and after leaving. Always wear gloves when handling any body fluids and when having physical contact with the patient.
Dispose of linen in the proper containers; in most facilities, these will be clearly marked so this linen can be handled separately.
Do not take responsibility for cleaning patient care items or items in the patient room. These tasks should be done by people from the housekeeping staff who have received special instructions.

Learning Break: Tuberculosis is not spread by skin contact, sharing food or eating utensils, from contact with toilet seats, or touching clothes or personal care items of someone with the active disease. However, many patients with tuberculosis have a compromised immune system, so precautions keep them safe.

Social Support and Nutrition

It is easy for a patient with tuberculosis to feel isolated. Many patients with tuberculosis may also feel somewhat ashamed, as if the disease was a negative stigma. People who do not understand the disease may avoid them. Fear of the future and fear of the unknown are also normal. Tuberculosis is not a common disease in the United States, and the patient is unlikely to have friends or relatives that have had disease, so there is no one the patient can ask about what it is like to have tuberculosis. There is no one who has experienced the disease that the patient can ask for reassurance.

Fortunately, you can provide the patient with valuable emotional and social support, and help with these feelings of isolation and fear. Simply listening is often best. You can also encourage the patient to speak with the physician about specific fears, questions the patient has about the prognosis of his/her case, and questions about the drug therapy. Above all, you can encourage the patient to comply with isolation precautions and drug therapy. If the patient has questions about these issues, always remind them: Following the isolation protocols is essential to prevent spreading of the disease, and complying with the medication protocol is essential for a cure.

It is also important that patients with tuberculosis eat well. Malnutrition and a poor diet can make the recovery period longer. Encourage the patient to maintain a healthy diet. If you observe that the patient is not eating well, make sure that you notify your supervisor or a dietician.

Drug Therapy

As mentioned in the previous section, it is absolutely essential that a patient with tuberculosis take all of the prescribed medications and finish the entire course of therapy. Drug therapy is the most important treatment for a patient with tuberculosis, and it is long and involved. Unfortunately, the length and inconvenience of the drug treatment is one of the major reasons why it can fail: people simply stop or give up. Another reason people stop the therapy is that after their symptoms have improved, it can be difficult to understand why they need several months more of drug therapy.

But if the person does not take all of the drugs or stops the treatment, a cure may be delayed or even not happen. Also, failure to follow the protocol can lead to multi-drug- resistant tuberculosis or extensive drug-resistant tuberculosis. There are many instances in which people who are taking isoniazid, rifampin, etc. will be supervised when they take the drugs: this is called directly observed therapy, or DOT.