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.
What is Tuberculosis?
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.
How does TB occur?
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.
People at risk
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.
Symptoms
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.
How to diagnose TB?
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.
How to treat TB?
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.
Supportive treatments
Drug
therapy is the most important part of treatment.
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.
Infectivity
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.
Prevention
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.
Drug resistance
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.
