Wednesday,
November 10, 1999
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The BCG debate — I TB: no cover now? By Dr S.K. Jindal Mycobacterium, once again, is the villain number one. It has got the dubious distinction in being responsible for the disease called tuberculosis, which has persisted for the past two millennia since pre-Biblical times. It afflicts several animal species, including cattle and man, and involves almost all organs, particularly the lungs. Return of
old dengue November
14 is World Diabetes Day How to stay fit |
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The BCG debate — I Mycobacterium, once again, is the villain number one. It has got the dubious distinction in being responsible for the disease called tuberculosis, which has persisted for the past two millennia since pre-Biblical times. It afflicts several animal species, including cattle and man, and involves almost all organs, particularly the lungs. The bacillus spares no section of society—the rich or the poor, the illiterate or the elite, the commoner or the V.I.P. Although the disease is more common among people living in crowded, unhygienic areas and slums, it in no way is unknown or uncommon in the affluent sections. While a similar attack-rate for all the exposed people is attributed to the bacillus being air-borne, the differences in the disease-prevalence are because of the biological and immunological variations between different groups of people. For the prevention of tuberculosis, we can either target or eliminate the agent (i.e. the mycobacterium) or increase the defences of the host (i.e. the human body). Vaccination is the most important tool for augmenting immunity against any infection. BCG has been used to prevent tuberculosis for over 70 years. But unlike most other vaccines, BCG has never been free from controversy. Its efficacy, in particular, has remained a point of discussion and repeated investigations. One of the largest studies on the efficacy of BCG conducted in Tamil Nadu in India has failed to show results. In 1978, these results were made known. These revelations shocked the people much more than the results of any other study showing negative consequences. But there was criticism by various investigators and statisticians who found errors related not only to the methodology and analysis but also to its interpretation. In subsequent years, the Indian Council of Medical Research (ICMR) removed most of the methodological flaws and continued with the follow-up study. The latest results reported after 15 years of follow-up are not different from those reported earlier. In sum, it has been said that the vaccination offers marginal benefit to children and none to adults. Where does this study lead us? Should we discontinue BCG vaccination? After all, the BCG programme involves a lot of government expenditure and requires skin-pricking with needles which occasionally may cause local or general problems. Before I delve into this question, I wish to show the other side of the coin and summarise the results of the trials from elsewhere, mostly reported in the late eighties or early nineties. The protective effect of BCG vaccination at the age of 15 to 24 years in England and Wales in 1983 was estimated as 75 per cent, the estimated efficacy in white Ethnic group it was closely similar (76 per cent). The protective effect of BCG in Norway in the first 10 years after vaccination was estimated to have been 80 per cent. The effect was higher during the first five years after vaccination. In Togo in Africa, the protective effect against all Types of TB combined was 61.5 per cent. The protective effect increased considerably with the severity of the disease. In children of five years or more, it was lower than in younger children. The BCG vaccination programme in Bangkok had an appreciable effect in preventing childhood TB and, most probably, also the late consequences of intrafamilial infections in early life. The observed level of protection of BCG was 74 per cent in Seoul. Several smaller trials from other parts of India, such as Agra, Ahmednagar and Mumbai, had shown variable protective efficacy. A meta-analysis of 14 prospective trials and 12 case-control studies found that BCG reduced the TB risk by 50 per cent. The decrease occurred across many populations, study-designs, forms of disease and age of vaccination. From the results of many studies it had also been concluded in statistical terms that the studies showing higher efficacy had narrow confidence-intervals, while those showing poor efficacy had wider confidence intervals. It essentially meant that the higher-efficacy studies practically excluded the possibility of low efficacy. But the low-efficacy studies did not exclude the chances of high efficacy of the vaccine. This is a scientific confusion which is difficult to understand for a common man who wants to live a healthy life—free from tuberculosis. Why we cannot come up with one conclusion which is true is a ticklish question which cannot be easily answered. This is how a biological science is different from the mathematical or physical sciences. It is worth concluding that BCG continues to be used in 182 countries or territories for its protective effect in children and against serious forms of tuberculosis. In a trial in Malawi, BCG was also shown to provide variable though significant protection against leprosy. There is no ground to doubt the results of the ICMR study. But it will be difficult for even the die-hard supporters of the study to advocate the complete abandonment of BCG until we find a more effective substitute vaccine. This is a goal which as yet is distant. But one lesson is clear: one would not perhaps introduce BCG vaccination as a new programme, had it not been operational before. But it need not be abandoned and rejected on the spur of a moment. On the other hand, there is no point in going on beating the BCG horse which is too exhausted. One need not waste any more time to prove its "possible efficacy" in another trial. One should rather invest in the ultimate goal—protection against tuberculosis—and look into the alternative methods. Fortunately, we do have some ray of hope on that score. (To
be concluded) |
Return of old
dengue This is post-monsoon and pre-winter time in North India and we are already in the know of hundreds of Dengue Fever (DF) cases being treated in the hospitals of Ludhiana, Chandigarh and Delhi. Despite the 1996-97 epidemic of DF in Ludhiana and Delhi, we are lacking in awareness of this insect-borne disease and its symptoms. During the past few years, DF has emerged as a major and recurring problem. Dengue is linked with poor environmental sanitation, inferior housing and inadequate water supply. It is transmitted by aedes mosquitoes. Mosquitoes breed quickly in stagnant water. The post-monsoon and pre-winter season is the conducive time for the precipitation of diseases transmitted through insects that breed in water. Malaria and filariasis are other such insect-borne diseases, besides DF. Aedes aegypti, the transmitter mosquito, is active during the day. The female, after biting a DF patient, may immediately bite another persons — or after an incubation period of eight to 10 days. During this time, the virus multiplies in its salivary glands. Mostly, DF begins with a headache or joint and muscular pains. Infants and young children may develop a feverish feeling and measles-like rashes. Older children and adults may, in the beginning, either have mild, feverish feeling or a sudden onset with high fever, a severe headache, pain in the eyes, muscles and joints plus rashes. The gums or the nose may bleed. There may be bleeding complications such as blood in urine, vaginal bleeding or gastrointestinal bleeding. Severe bleeding may cause death. The four grades of severity of this fever are identified by the World Health Organisation (WHO) as shown in the table. This fever enters a critical period of Dengue Haemorrhagic Fever (DHF) after the third day of the attack. Blood capillaries become fragile. There is plasma leakage and concentration of red blood cells. Repeat platelet counts should be done and the percentage of the volume occupied by cells in a blood sample should be determined. As in diarrhoea, the patient should be frequently fed on fluids. In mild or moderate cases, the symptoms disappear with time either spontaneously or through electrolyte therapy. The patient should be immediately hospitalised if he shows: * Restlessness * Cold extremities * Rapid and feeble pulse * Hypertension (low B.P.) * A rise in red blood cells concentration, despite fluid therapy. The patient may go into a shock with the above-mentioned symptoms. It is a medical emergency for him/her. Instant replacement of intravenous fluids is essential. People who have suffered from secondary infections in childhood and primary infections in infancy are more prone to DHF. A recent report published in the Journal of Tropical Paediatrics shows that there was generation of free radicals (cells that tend to harm vital organs) in children down with DF. For this study, during an outbreak in Delhi in 1996, 66 children between 45 days and 12 years of age with DF were studies for biochemical abnormalities. According to the WHO criteria, 14 children were suffering from classical dengue (DEN), 42 with dengue haemorrhagic fever (DHF) and 10 (including three who died) as having dengue shock syndrome (DSS). In a study conducted by Dayanand Medical College and Hospital, Ludhiana, out of 505 patients admitted for DF, 66.9 per cent were male and 33.1 per cent were female. The age group of 21-40 years was found to be the most affected. Twenty-eight patients died because of the infection that aggravated into DHF and DSS. As many as 452 patients recovered. Of these 340 had severe infection and their stay in the hospital ranged from four to 21 days. One hundred and twelve patients with mild infection were discharged within three days. Fever and a drop in platelet count were the most common findings followed by headache/bodyache and vomiting. Upper gastrointestinal bleeding, blood in urine, nose-bleed and bleeding from the gums were noticed in 34.4 per cent of the cases. The study was published in the Indian Journal of Medical Research. An outbreak of DHF in a community should be suspected when: * Children with high fever of two to seven days fail to respond to treatment for malaria, pneumonia, pharyngitis, etc. * The patient has red spots on the skin and bleeding from the nose or gums. * The patient remains restless, drowsy, cold and sweaty despite a drop in the temperature. In rare cases, the central nervous system of DHF patients is affected. Convulsions, cerebral oedema and intracranial haemorrhage have been found in cases of DHF. Life-threatening gastrointestinal bleeding occurs in severely ill patients. Prevention: Two main directions to control an outbreak are: 1) Emergency mosquito control and (2) immediate treatment of patients in hospitals. Dengue is a constant threat in the thickly populated and polluted, industrial cities of India. There is a need to take strict preventive measures. The rainy season, post-monsoon temperature and humid conditions breed and spread the virus. During this season, communities should participate in activities that help in controlling the virus. Old, unused objects (torn tires, empty tins and bottles) should be disposed so that they do not collect water. If open jars and drums are lying uncovered, they should be turned upside down. These containers should be cleared and scrubbed periodically so that larvae and eggs of the mosquitoes are destroyed. Water tanks and drums should be properly covered. Insecticides
should be sprayed in the areas of the outbreak so that
adult mosquitoes that carry the virus are killed. All
open spaces should be filled with sand or cement to
prevent the accumulation of water and mosquito breeding. |
November 14 is World Diabetes Day Diabetes has become the most common, single cause of kidney failure, blindness and loss of manliness (impotency) and the leading factor for heart disease and paralysis. All these contribute not only to physical disability of the sufferer but also account for a major economic strain on the family. These are due to the fact that the prevalence of diabetes is increasing, diabetes patients live longer now and various treatment modalities for health problems are becoming common knowledge. In the coming quarter of the 21st century, our diabetic population would double. India would become the country of the largest number of patients with diabetes. This increase in the number is disproportionate to the increase in the population. With the cost of diabetes care on the rise, many will fail to afford the treatment despite their willingness to do so. The prevention of type II diabetes is possible by healthy eating and healthy living. Avoid visits to fast food centres, ice-cream parlours, bars and dinner parties. Try to maintain your weight which should be proportionate to your height, and eat as many calories as your work demands. Keep a close watch on your waist line and measures of stress (hours of sleep, without the help of pills and/or alcohol). If you are a diabetic, keep your sugar, cholesterol and blood pressure under control to minimise the risk of kidney failure and heart ailments. Diabetes is not a curse but a blessing in disguise. Let us call it a challenge for remaining healthy and living longer. Change family burdens to advantages through a live demonstration of healthy living to misguided younger members. (Professor
Dash, the widely known diabetologist, heads the
Department of Endocronology at the PGI, Chandigarh) |
How to stay
fit The level of fitness for physical work and exercise is an important determinant of cardiovascular health and longevity. It can be improved by physically active life-style and regular exercise and can be objectively measured on a treadmill. But, for all practical purposes, if you can walk uninterruptedly and without difficulty I mile (1.6 km) on level ground at a brisk speed ( 120 paces per minute), your fitness level is adequate for the health of your heart. It means that both the heart and lungs, on which longevity mainly depends, are in good shape and well conditioned. It has been proved beyond reasonable doubt that physically fit people live longer and have minimum of health problems, especially those related to the heart. Physical fitness is even more necessary for those who suffer from hypertension, diabetes, obesity, angina or those who have had a heart attack. It is therefore important for you to keep yourself at an adequate level of physical fitness. Risk Reduction The reduction of risk to the heart obtained by physical fitness is substantial. Different studies put it at 40 to 65 per cent. It is no less, probably more, than the one obtained by stopping smoking. All persons who improve their level of fitness improve their cardiovascular system irrespective of their age and baseline fitness level. It is, therefore, never too late to make a start with a physical-fitness programme. What physical fitness does to your heart: What do you gain by making and keeping yourself physically fit ? By giving enough exercise to the heart and lungs, you open up the lung alveoli (air spaces) and, therefore, maximise oxygenation of your blood. You improve lipid profile; blood sugar is kept at a healthy low and the likelihood of blood clotting is reduced. Blood pressure and body weight remain under control. Stress levels are reduced; you eat better and sleep better. All these changes prevent the development of ischaemic heart disease. On top of this, you open up the collateral channels of blood in the heart and thus keep it ready to meet any challenge from coronary thrombosis, if it does occur. To keep yourself physically fit, you do not need to exercise excessively. In fact, excessive exercise is counter-productive and harmful. What you really need is moderate exercise. See next chapter to find out for yourself how easy it is to keep yourself fit and earn longevity. Obesity The advice of Dr G.D. Thapar on exercise should read thus and not as published in Health Tribune (vigorous exercise is not indicated):" To prevent losing muscle while reducing weight, it is important to eat enough of proteins such as cheese, chicken and fish-- and exercise." Health Bulletin The
Trikha Medical Mission run by Dr Chander Trikha (473,
Sector 32-A, Chandigarh), has started a health bulletin
for private circulation. The philanthropic venture is
laudable. The first issue has several articles, including
one that says: "Turmeric can save your
heart"—Health Tribune |
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