Our learned expert also has following feathers in his cap.
v General Secretary of Pakistan Chest Society (Punjab)
v Member Pakistan Chest Foundation
v Member Faculty of Chest Diseases and Tuberculosis ,College of Physicians and Surgeons of Pakistan
v Member National Asthma Council Islamabad.
This interview was conducted in his office at Institute of Chest Diseases, Mayo Hospital Lahore on November 15th 2000.Panel consisted of Dr Ehsan Asad, Dr Capt Liaqat Ali Chaudhry, Dr Mehboob Ashraf and Dr Saleem Akhtar Rana.Following script has been prepared from the informal discussion which lasted for more than 2 hours. Any error or omission is the responsibility of Panel.
TB is most widespread of human ills. Pulmonary Tuberculosis is being overdiagnosed but undertreated. ATT is being prescribed without proper minimum investigations, even without X-ray chest. Then insufficient combination, in lower dosages, for shorter than required periods. This is being labeled as lack of doctor’s compliance.
Current Shortcomings shared by all levels of physicians.
q Education of Patients.
Most of the times diagnosis is hidden from patient. He is not educated about the disease. As he is not told about the duration, side effects and taking drugs on empty stomach, result is poor compliance. Patient needs education on the colour of urine while taking drugs. Very strong patient education initiative is compulsory part of the compliance.
q Duration of Therapy.
First time therapy shall continue ideally for 1 year. Minimum duration shall not be less than 10 months. First 3 months four drugs shall cover intensive period. Next 9 months at least 3 drugs shall be continued. Concept of Initially three drugs and later on two drugs is no more valid in the face of very high resistance rate against INH.It is 39 %. Four drugs are used for 3 months followed by continuous phase of Rifampicin, INH and Ethambutol for 9 months.Following 5 drugs as first line drugs.
v Rifampicin
v INH
v Ethambutol
v Streptomycin
v Pyrazinamide.
Basic duration and treatment for pulmonary and extra pulmonary TB is same with few exceptions.
Duration for CNS or Bone joints TB shall be 18 months.
q Dosage of drugs.
Weight of all patients shall be measured. Dose must be on per/Kg basis. All medicines must be taken simultaneously, in single dose, and on empty stomach i.e at least ½ hour before meals. If patient can not tolerate in the morning due to nausea or vomiting, it can be taken at bedtime.
Nowadays fixed drug combinations are being prefered to avoid monotherapy (so resistence) and to increase the compliance. Myrin one tablet per 15 kg and Myrin –P one tablet per 10-kg body weight is enough. If patient is above 70 kgs, then one tablet of ethambutol and one of pyrazinamide shall be added to this calculation.
q Side Effects.
Before initiating the ATT patient shall be thoroughly educated on side effects. So that if he faces any problem, he does not discontinue the treatment. Most common side effect is nausea and vomiting. Jaundice, visual changes and neuritis symptoms shall be explained. He shall be educated about the red colour of urine while taking drugs.
Message for self-correction.
Initially gather all possible evidence in favour of diagnosis of TB.Chronic cough, Fever of longer duration, and weight loss are not the symptoms and signs of Tuberculosis only. Xray, sputum, history of contact, Mountoux ‘s test, CBC & ESR, etc shall be done before the diagnosis is made. Let us not hurry with the diagnosis of TB.Let us take time and gather evidence (rather than history of failure to other therapies). Let us explore all avenues of diagnois e.g history, examination and investigations, before we commit ourselves to TB.
But once this diagnosis is labelled then we proceed with full regimen of four drugs, for first 3 months and 3 drugs for next 9 months. Proper doses.mgs/kg basis.
Therapeutic trials are justified only in old age with PUO where cryptogenic TB may be lurking somewhere without producing any visible tell tale evidence.
Essentials of Diagnosis of Tuberculosis.
History shall strongly suggest the possibility of Tuberculosis.Examination should be thorough. Investigations shall include followings.
q Definitive diagnosis for tuberculosis is smear positive for AFB and then culture of these AFB.Final step may be added under ideal conditions. DNA PCR for recognition of strain of AFB.
q Culture of AFB is not available even in Lahore in private sector or other Govt Hospitals.It is only available in PMRC or TB clinic in KEMC/Mayo Hospital Laboratory.
q Each case of pulmonary tuberculosis must have at least one smear examination.
q Ideally 3 samples of sputum shall be examined for AFB.2 of these 3 should be positive to label the patient as smear positive.
q Food particles in sputum resemble AFB.So empty stomach sputum collection is preferable. Patient shall first clear his mouth and throat of salivary secretions. Then he shall be instructed to take deep breath and cough out sputum deep from chest. That shall be collected for examination.3 collections at interval of at least 12 hours is enough.
q About 20 –25 % of all patients suffering from Pulmonary TB shall be smear positive. If cavities are visible on xray (denoting the activity of disease) smear positive rate shall go on to 40 –50 %.
q Smear negative sputum does not rule out diagnosis of TB.
2) X-ray Chest.
Though an important landmark in the diagnosis of Tuberculosis but practical experience has proved that no radiodiagnostic picture or pattern is absolutely typical of TB.
q ATT for Pulm TB shall never be started without Xray chest.
q There are many regions on X ray chest films, which are known as hidden or missing areas due to poor visibility on typical PA views. These are retroclavicular areas, costopherinic and cardiopherinic angles. Different views may be advised to clarify doubtful areas. Lordotic view to highlight retroclavicular areas.
q Approximately more than 100 pathologies can cause abnormal shadows on X-ray chest and many diseases of lungs show similar radiodiagnostic appearances.
Most common causes in our settings are
3. Bronchogenic Carcinoma
4. Abscess
5. Bronchopulmonary Aspergilosis
6. Pneumoconiosis.
7. Sarcoidosis
8. Lymphomas
9. Bronchiectasis
10. Fibrosing Alveolitis
11. Mitral stenosis
q There is no typical tuberculous lesion. But certain lesions on x-rays can be labeled as to be most likely to be tuberculous.Right apex and left mid zone are frequent areas.
q Cavities are usually due to Tuberculosis, abcess or malignancy. Mottled areas usually surround tuberculous cavities.
q In paediatric patient’s peripheral lesions are usually missing. Unilateral hilar lymph node enlargement strongly predicts presence of Pulm TB.Typical Gohn’s complex consists of a focus in the periphery, lympangitis pointing towards hilum and then hilar lymph node enlargement. Peripheral lesion and linking lymphangitis is usually missing on X-ray films.
q Usually lesions above hilar shadow point towards the probibility of typical TB.Lesions lower than hilar shadows should prompt to look for other causes or atypical picture of Pulm TB.
q In old age hilar lymp node enlargement is not a feature of Pulm TB.In adults parenchymal lesions are common than lymph node enalargements.
q In older age group unilateral hilar lymph node enlargement along with peripheral lesions is against the probability of Pulm TB.
q Calcification and fibrosis may be evidence in favour of Tuberculosis.
q In retreatment therapy or relapses single current X-ray film is of no value. Untill previous films are available these x-rays shall be given no wieght. In AGUH one patient is on record , taking ATT for last 14 years just on the basis of fresh films each time he is visiting a new doctor.
3) Mantoux Test
q If performed properly in our community positive rate shall be around 60-70 % in normal adult population. These high rates are due to BCG vaccination and frequent exposure to bacilli. Much lower rates reported in the day to day practice are due to improper commercial preparations and techniques. Commercially available ready to use test units like MONOTEST is not ideal. Ideally PPD should be injected intradermally by the doctor himself with a needle.
q Interpretation shall be after 48 –72 hours. Area of induration shall be measured. In BCG Vaccinated person’s Positive result means more than 10mms diameter. In non-vaccinated individual more than 5-10 mms is positive. A scar of vaccination shall evidence previous successful vaccination.
q It has no role to play in the diagnosis of adult TB.Diagnostic value is different in different ages. In adult population negative result may be an evidence against the diagnosis of TB.For example in an old patient of bilateral hilar lymph node enalargement negative Mantoux’s test is an evidence in favour of Sarcoidosis rather than Tuberculosis.In young children who have not recently received BCG vaccination there is some importance of Mantoux Test.
4) Recent Investigations
Unfortunately tests having no diagnostic values are being used unnecessarily.
v Mycodot Test
v Immunoassays for antibodies or serological diagnostic tests for TB
v PCR
Have yet to prove their efficacy and reliability as routine diagnostic tests.
5) Bactec System for Diagnosis
It is a short cut to routine Culture studies. Using radioactive substances this test can predict the result of culture in 14 days instead of traditional 3 months. This was available in Gulab Devi Hospital.
Monitoring of Therapy.
q Smear positive cases shall become smear negative in 2-3 months but patient can become non-infectitious after 2 weeks.
q X ray evidence of improvement in a lesion shall be their to declare therapy effective and successful.
q Physical improvement of patient shall always be there as final proof of effectiveness.
q Stipulated period shall be completed before therapy is discontinued.
q ESR is a poor indicator as monitor.
Retreatment or Relapse of Tuberculosis.
If therapy has been discontinued before time and two months interval is there, treatment shall be restarted as on day number one.
In relapses following two evidences must be there before diagnosing reactivation of TB in a previously successfully treated patient.
1 Smear Positive
2 Comparison of old X-rays and fresh X-rays shall show new lesions or extension of old ones.
This is the threatening new white plague, which is causing terror on international level. In Pakistan there is sizeable population of patients who fall under this category.
Any patient who is resistent to at least two drugs i.e Rifampicin and INH (along with or without other anti TB drugs) is labeled, as MDR TB.Culture shall prove it or following guidline shall be followed.
The phenomen of MDR is mainly man made on the part of doctors as well as the patients.
How to Label?
If patient does not respond to retreatment regimen. If sputum does not become smear negative in five months and if there is no clinical improvement then patient is labelled as having MDR TB.If C/S reports are available then treat according.
Second Line Drugs.When to start?
If above mentioned regimen of 5 drugs fails to produce clinical improvement or smear does not become negative after 5 months only then second line drugs are used. These are continued for 18-24 months.12 months’ therapy after sputum conversion.
Followings are the second line drugs.
v Cycloserene
v Ethionamide
v Thiacetazone
v PAS
v Kanacin, Amikacin
v Ofloxacin Ciprofloxacin
Availability is problematic. Costs are unbelievabley high. Rs 10,000-15,000 per month. Side effects are near to intolerable. So please remember FIRST TIME treatment is the best treatment.
Importance of BCG
Present BCG vaccine does not prevent infections but may prevent serious infections like Meningitis in children.
It has proved quite useful in decreasing the morbidity and mortality due to extrapulmonary tuberculosis. It shall be given at three times.
At birth
At the start of school going age, 5 yrs
At the end of School going, 15 yrs.
Message to Fellow Professionals.
Unfortunately faulty prescriptions, inadequate dosages, unsupervised treatments, non compliance of patients, use of substandard drugs and inadequate knowledge given to patients by the doctors regarding duration of treatment are important factors contributing to MDR.
Unfortunately this is a reflection on our part that the training and education imparted to the doctors are focused on such diseases, which can hardly be seen in this country. There is need to change the curriculum of medical education and stress upon the diseases playing havoc in our society like TB Malaria Typhoid and Bronchial Asthma.
Doctors should be trained as attentive listeners, careful observers and sensitive communicators and effective clinicians.