Tuberculosis, a disease with which both the medical personnel and the lay are quite familiar perhaps tops the list of scourges in the history of man. Known for about 10000 years, the disease has killed men and animals throughout the world in all centuries. It was known as ‘Phthisis’, the Greek equivalent of ‘consumption’ of the lungs that consumes the whole body:
“Whilst meager Phthisis gives a silent bow,
Her strokes are sure but her advances slow”.
In the medieval era it was the King’s Evil – a malady which could be cured only by the touch of the King, the sovereign. Its notorious killing power can be judged from the fact that it was responsible for the deaths at younger ages of celebrities such as John Keats, the poet, Emily and George Orwell, the authors, Vivien Liegh, the actor and Joseph Priestley the scientist. Kings and other powerful people such as the First Lady Eleanor Roosevelt, Mohammad Ali Jinnah, the first President of Pakistan and Kamla Nehru also fell victims to this curse. Ironically, Rene Laennec, the discoverer of the stethoscope, which was the first instrument used to detect/diagnose TB of the lungs, himself, like many others engaged in work on tuberculosis, contracted the illness and died from the same.
Tuberculosis (TB) is an ancient disease which probably spread from the cows when the men started living in communities along with the cattle. The first possible reference to the presence of a chronic disease (perhaps tuberculosis) was made in the Code of Hammurabi in Babylonian culture of about 2000 BC. But more definite evidence of tuberculosis (of bone) was found in an Egyptian mummy of the Early Dynastic period (3400 BC). There is some suggestion of TB in the Indo-Aryan civilization of 1500 BC while the Ayur Veda (about 700 BC) contains a more detailed description of TB, known as ‘Yakshma’ in the Sanskrit scripts.
Tuberculosis is a disease of the respiratory system, in particular the lungs. But it can involve almost all other organs such as the lymph glands, intestines, liver, heart, kidneys, brain, genital organs, skin, bones and joints. Sometimes, the disease is severe, may disseminate and involve more than one organ especially in a patient whose own defence system is weak.
Tuberculosis is an infectious illness caused by the micro organism called Mycobacterium tuberculosis or Tubercle bacillus (T.b.) commonly referred to as the acid fast bacillus (AFB). The tubercle bacilli enter the body through the respiratory tract in the inhaled air. The mycobacteria are coughed out by patients with TB and remain suspended in the droplets of sputa in the air. Once the T.b. enter the body, different body defences tend to stop their progress. Tuberculosis, like any other infection results from constant battle between the invaders and the body defences especially the immune cells. If the invaders (i.e. the mycobacteria) are able to overcome these defences, the infection takes its roots in the lungs. This is called primary TB i.e. first time infection in the body.
It is interesting to know that more than half of the Indian population shows evidence of the presence of infection with the mycobacteria i.e. a positive skin test (Mantoux test). This is generally innocuous since the bacteria remain dormant in the body. Disease, which means the presence of clinical symptoms, may result whenever the mycobacteria start actively multiplying due to compromised immunity.
Infection is likely whenever the defences are weak such as in individuals with immune deficiency in the elderly, the malnourished, the drug abusers and those with pre-existing or concurrent illnesses. Infants and very young children may also develop TB before they have acquired immunity against TB. Patients with human immunodeficiency virus (HIV) infection are particularly liable to develop the disease because of the deficiency of the cells which do normally provide immunity against TB. Patients with diabetes mellitus, chronic liver disease, malignancies and diseases requiring chronic treatment with immunosuppressive drugs (e.g. corticosteroids and cytotoxic drugs) are quite prone to develop TB. In diabetics, the disease is 2 to 6 times more commonly seen than in normal individuals.
Tuberculosis is also more likely in people living together in homes and with poor living conditions (such as in slums, huts, roadside pavements, prisons etc.). It is therefore more common among the poor though the rich and the educated are also affected. Both men and women are equally involved. People who smoke tobacco, especially heavily, and/or abuse drugs develop TB more often. Health care workers in hospitals and nursing homes are also more prone to TB. Chances of spread of mycobacteria are more whenever a living area is crowded and ventilation is poor.
The common symptoms of TB are the presence of fever, cough and sputum production. These are present in over 80% of patients. Patient may also complain of blood in the sputum which has been traditionally considered as a sine quo non of TB. The famous example is that of Keats, the famous poet who diagnosed his own TB on seeing blood in his sputum. It is now recommended that any person who complain of cough for at least 3 weeks or more must get his/her sputum examined for diagnosis of TB. Tuberculosis was called as ‘consumption’ in the past implying the presence of a significant weight loss. This is however not necessary to have weight loss in every case of TB.
Other general symptoms may include the presence of malaise, fatigue, weakness, loss of appetite and ill health. Patients with TB of organs other than lungs may complain of symptoms related to the involved organs. Local swelling, ulceration and sinus formation are common symptoms of TB of lymph glands and skin. A patient with abdominal TB may complain of abdominal discomfort or pain, constipation and/or diarrhoea, abdominal bloating and distension. Urinary TB may cause increased frequency of burning and pain during urination, blood in the urine and abdominal pain. TB of genital organs may cause local swelling, ulceration, pain and discharge. Infertility is a common sequalae of TB of the genital tract especially in case of women. Bones and joint TB may cause local swellings, pain and restriction of movements. TB of the nervous system causes fever, headaches, vomiting and neurological deficits.
In summary, TB may present with protean manifestations and complaints. Not infrequently, the diagnosis of TB is possible even in the absence of the characteristic symptoms or clinical features.
An individual with one or more of the symptoms as above needs to seek medical opinion especially when the symptoms persist or recur frequently. Diagnosis of TB of the lungs is relatively easy. Any patient who has cough and/or sputum for more than 3 weeks should get his/her sputum tested for the mycobacteria from one of the centres being run under the Revised National TB Control Programme (RNTCP) where the tests are undertaken free of cost. Most of the good private clinics, laboratories, semi-governmental health care centres and other institutions can also do the same. The diagnosis is considered established if the tests show the presence of the AFBs. Other investigations such as the chest x-ray are required when the sputum test is either negative or inconclusive.
TB of organs other than the lungs is relatively difficult and several different tests are required. Suspicion arises whenever there is presence of one or more symptoms described earlier and the common causes of those symptoms are excluded. It is always better to go according to the advice of the doctor rather than wasting money on tests on self made decisions and choices. Both the methodology and the interpretation of a test are important before one puts the diagnostic label of TB. Results of most of these tests are not necessarily absolute and the diagnosis may at best be considered as ‘suggestive’ or ‘probable’. A confirmed diagnosis of TB in the absence of the AFB can be relied only if a number of other clinical radiological and laboratory features are present.
Treatment of pulmonary TB is fairly standard. The treatment of a new patient will last for 6 months. The treatment centres run under the RNTCP provide free treatment under direct supervision – a strategy called as Directly Observed Therapy, short course (DOTS). Each patient is assigned a separate number and the total treatment of 6 months for that patient is earmarked. Under this strategy, the standard four drugs are administered to the patient on alternate days by the DOTS provider for the first two months. The number of drugs is reduced to two for the ‘continuation phase’ of 4 months. During the continuation period, the drugs to be taken on alternate days at home are provided at the DOTS centre to the patient on a weekly basis. The DOTS strategy assures compliance of treatment and prevents misuse of drugs, therefore avoids resistance to the drugs.
The most important issue in TB treatment is the need for completion of therapy. It is for this very reason that the DOTS strategy has been advocated and stressed. Drugs are generally taken in the morning but a fasting state is not essential. But one must take treatment even if fasting for any personal or religious reason. Similarly, the anti TB treatment should be continued during pregnancy, lactation and in the presence of other minor illnesses e.g. cold, fever, headache, diarrhea etc. Drugs are withheld if there is a severe reaction or some other toxicity of the drugs.
One needs to consult one’s doctor in case there is a reaction to a drug or if there is another concurrent medical problem. Skin eruptions, nausea, vomiting or fever may point towards an adverse reaction to a drug. Patients receiving an essential anti TB drug (i.e. rifampicin) are likely to pass orange or deep coloured urine. This in itself is non-consequential, but can be confused with jaundice caused by liver toxicity due to the use of anti TB drugs. Liver toxicity is suspected if there is loss of appetite, aversion to food, vomiting and fever (etc). Blood tests for liver function should help whenever there is a suspicion.
Drug therapy is the most important part of treatment.
A good diet is important to prevent weight loss. There is no special diet recommended for a patient. Supplementary proteins and vitamins, milk, cheese and eggs are useful but not crucial in case a patient cannot afford the same. These items do not constitute an essential component of TB treatment. TB patients must strictly avoid smoking and alcohol drinking.
Exertional activities such as taking part in sports, heavy exercise, active work or sex life should be avoided at least during the first few weeks of treatment or until the sputum remains positive. But there is no need to lie in the bed unless the disease is severe and disabling. Patients with chronic but localized disease in the lungs especially those who continue to bleed, may be helped through surgical options in addition to the medical therapy. Surgery of the lungs is required only under rare circumstances, in view of the proper drug therapy being so effective.
As pointed out earlier, TB spreads through the respiratory tract. Presence of tubercle germs in the sputum indicates that the diseased individual can pass on the infection to others, close members of the family, friends in an office or even innocent fellow travelers coming in short contact. When a diseased person coughs openly, he or she discharges millions of TB germs in the local environment which are inhaled by others. Loud talking or singing can also disseminate germs in the room atmosphere. On the other hand, if most of us follow the civilized practice of coughing into our own handkerchiefs, then the germs are contained within the cloth itself. Patients with abnormal chest x-ray and negative sputum are less of a danger as far as others are concerned.
An infective patient, who is secreting AFB, in his/her sputum can infect others living in his close contact especially in case of children and the immunocompromised patients. Healthy adults generally do not get infection in this fashion because of the presence of immunity which develops in them from environmental exposure to the mycobacteria. But caution needs to be exercised. For example, close physical (e.g. kissing) and sexual contact with a patient may spread the infection.
There is no need to isolate or hospitalize each patient of TB. Domiciliary treatment is recommended for all patients. Admission is required only in the presence of a complication or a drug related problem. The risk of developing similar infection among the household members or close contacts is there so long as the patient remains without treatment. Once treatment has started, the infectiousness of the patient towards others drops rapidly. Disposal of infected sputum may be carried out in two convenient ways. The patient can cough into paper, napkins or a newspaper cut into convenient sizes, collect them throughout the day in a container and then burn these. Alternatively, the expectoration is allowed to settle in a receptacle having liquid phenyl at the bottom. The contents can later be discharged into a sewerage system.
Utensils, clothes and food eaten by the patient ordinarily do not disseminate the disease. Direct face-to-face contact and breast feeding should be avoided. These precautions are required in the case of sputum positive patients. Children and pregnant women suffering from tuberculosis should consult specialists in the field.
Tuberculosis is a preventable disease. The means of prevention are a prompt treatment of active cases, BCG vaccination of all children below the age of 14 years and prophylactic treatment of high risk persons such as nurses, doctors, close contacts of patients. Controversy exists regarding the efficacy of BCG vaccination. But it is definitely useful in children especially in prevention of serious forms of TB. The methods of prevention include the adoption of hygienic and health measures and administration of BCG vaccination to all newborn babies. Household contacts of patients need close monitoring.
Anti TB treatment prescribed on a standard protocol (i.e. DOTS) lasts for 6 months in a fresh patient and 8 months in a patient who has failed on treatment of TB or has relapsed/recurred after treatment in the past. There is no benefit of prolonging the treatment or irrationally adding more drugs. Response to treatment is best judged by improvement in symptoms and conversion of sputum from the positive to negative state.
There are a few patients who show the presence of resistance to the drugs and remain sputum positive. Most of these patients have been erratic and noncompliant in their earlier treatments. The disease is generally extensive in such patients. They require a good assessment for the presence and the reason of drug resistance. Some of them are likely to suffer from concurrent diseases such as HIV infection, diabetes or other serious illnesses. Treatment of drug resistant TB is prolonged – for about 2 years. Multiple drugs which are costlier and more toxic, are required. Drug resistant TB is better prevented than treated and the secret of prevention lies in the completed treatment of new cases.
In summary, TB which has caused misery to man for several millennia is a curable disease provided it is recognized in time and treatment is taken with full compliance. It is also preventable to a great extent. The methods of prevention comprise of treatment of sputum positive cases. Standard regimen as per the recommended guidelines is the key to the treatment. Individual choice of drugs and treatment regimens must be avoided. The disease can be potentially eradicated provided one remains very vigilant. Yet it is likely to persist for a few more decades.