| Let us suppose for discussion purposes that a | | | | soon, the bacteria can rebound with a vengeance. It |
| middle-aged lady comes to the physician’s office | | | | can become resistant to drugs, and in the extreme |
| for her annual physical exam. She has been feeling | | | | case, they become resistant to all the drugs, usually |
| well and essentially has no physical complaints. Her | | | | with fatal consequences. The drug resistant bacteria |
| physical exam is within normal limits. Because she | | | | may be passed along to others. The infection is |
| has been doing volunteer work at the homless center | | | | spread by the micro-droplets in a cough or sneeze. |
| the physician recommends that she have a T.B. skin | | | | Each droplet can contain enormous number of the |
| test. Either a TB tine test or a PPD (Purified protein | | | | bacteria. It is usually carried into lungs. Usually the |
| derivative) skin test is administered. In both rest a | | | | lower part of the lower lobe is first infected and then |
| small amount of TB protein is injected into the | | | | it moves to the lower part of the upper lobe. It sets |
| subcutaneous layer of the skin. In order to read it, | | | | up in the air sacs called alveoli and enters cells called |
| the patient must return in 72 hours. It cannot be | | | | macrophages. The body sends many types of |
| read reliably prior to that time duration. The | | | | defensive cells to combat it, and these may bring |
| physician evaluates the skin at the injection site. He | | | | about a walling off of the infection into its dormant |
| is not just looking for redness alone, but for an | | | | phase. If this doesn’t happen the infection can |
| elevating reaction that feels sort of like a coin in size | | | | grow into abscesses in the lung or spread to other |
| of 1 cm or larger under the skin. If it is there, the | | | | organs by way of the bloodstream. |
| presumption is that the patient has inhaled some | | | | The developed countries of the world become |
| Tuberculosis since her last negative skin test. The | | | | pretty comfortable with tuberculosis during the |
| physician may order a gamma interferon assay blood | | | | 80’s and 90’s. Gwinnett County, Georgia in |
| test because it is much more accurate and can help | | | | the last 5 years has dramatically increased its T.B. |
| sort out a false-positive skin test. Now, it’s | | | | population. It was generally thought of as a disease |
| time to really intensify the history review. Does she | | | | of developing countries, you know, “over |
| have an unusual cough, and if so, has there been any | | | | there.” No new drugs came on the market and |
| blood in her sputum? Has she had fevers, felt hot | | | | the resistance problem began to grow. Now, with the |
| at unusual times, or had nightsweat? Has she lost any | | | | developing of “globalization”, anything which |
| weight without intending to do so? Has she felt | | | | happens in any part of the world is a concern to us |
| fatigued, had difficulty breathing, had chest pain or | | | | all. Travel into and out of endemic areas is increasing |
| wheezing? This is very important information. Finally, | | | | in frequency. A lot of infection is associated with the |
| the doctor orders a chest x-ray and looks for any | | | | arrival of immigrant populations. The other |
| evidence of active disease. | | | | phenomenon is the development of H.I.V., in which |
| At this point there are three possibilities. The | | | | infection can be more severe, more drug-resistant, |
| patient may have had a false-positive skin test. The | | | | and require more intensive plans of treatment. |
| gamma interferon assay blood test would reiterate | | | | Face it: Tuberculosis is out there. Eight million people |
| this fact. The second possibility is that the patient | | | | world-wide become sick each year with infection. |
| inhaled T.B. germs which have attacked her body | | | | Fourteen million have active disease at any given |
| defenses, and forced into a quiet and dormant form | | | | time. Over a million die with it every year. Cases in |
| for decades waiting for the chance to overwhelm | | | | developed countries are increasing due to H.I.V., |
| the body defenses. This is called latent infection. The | | | | immunosuppressant drugs, and drug abuse. Many |
| germs can persist in their dormant form for decades | | | | things increase the chances of infection like silicosis, |
| waiting for the chance to overwhelm the body | | | | cigarette smoking, and nutritional deficiencies such as |
| defenses. The patient could have active disease, as | | | | inadequate vitamins B12 or D. It is seen with |
| evidenced by an abnormal chest x-ray and sputum | | | | increased frequency with the homeless, in infants and |
| positive for germs on microscopic exam or by | | | | the elderly, or with people who live in crowded |
| culturing the sputum for several weeks. Now the | | | | unsanitary conditions. Remember our patient who |
| physician must weigh all the facts at hand. Does the | | | | volunteered at the homeless center: The more you |
| patient have latent or active disease? If all findings | | | | are around people with the disease, the more likely |
| suggest dormant disease, the patient is placed on | | | | you are to become infected. |
| isoniazid (INH) antibiotics for one year. The patient | | | | A lot of research is going into vaccines, possibly |
| must come in monthly for blood tests to make sure | | | | including one with intranasal dosing. There are new |
| her liver is not being adversely affected. If she has | | | | antibiotics in trials right now for multi-resistant strains. |
| active infection she is placed on four drug therapy | | | | Research is being directed toward increasingly |
| including INH, rifampin, pyrazinamide, and ethambutol. | | | | accurate and inexpensive blood tests for dormant or |
| This is continued for at least two months until the | | | | active disease. International efforts are underway to |
| cultures come back. She is usually non-infectious after | | | | bring effective treatment to the ill in developing |
| two months of this therapy, and medications can be | | | | countries. We can increase our personal awareness |
| deleted or added according to the culture results. The | | | | and knowledge about this infection. We can make |
| treatment should bring resolution of the infection in | | | | skin or blood testing a part of regular physical exams. |
| six to nine months but sometimes as long as 2 years. | | | | We can support causes and organizations whose goal |
| This latter situation would, by law, require a report to | | | | it is to eradicate tuberculosis from the planet. We can |
| the local Health Department so they could test all | | | | practice the courtesies of hygiene to prevent the |
| contacts and ensure resolution of the spread of | | | | spread of infectious diseases to other people. We |
| disease. | | | | can identify segments of our population most in need |
| The problem with T.B. therapy is that patients, | | | | of infection surveillance. By research, political |
| world-wide, do not take their medicines as prescribed. | | | | commitment, and dedication to facing this human |
| Sometimes they don’t feel bad anymore and | | | | condition, we can move toward the day that we are |
| just stop taking them. In some places the drugs are | | | | making progress in the prevention and treatment of |
| expensive and are stopped for that reason. | | | | this horrible disease. |
| Whatever the cases, if the drugs are stopped too | | | | |