70 I MANAGEMENT OF HYDATID DISEASE
Tropical Doctor, April I976
Management of hydatid disease Khalid Naji, MS Professor of Surgery, Medical College, Baghdad, Iraq
TROPICAL DOCTOR
1976, 6, 70-73
Hydatid disease has a long history. It is referred to in the Talmud as "water bladder". Hippocrates mentioned it in his Aphorisms and Al-Rhazi referred to it in describing the diseases of the liver. Rudolphi gave it the name of vesicular echinococcosis in 1808 although Francesco Redi recognized it in animals in the seventeenth century. Leuckart described the cycle of development of this helminth in 1886. This disease can be caused by anyone of several species of the genus Taenia echinococcus - Echinococcus granulosus, E. multilocularis, E. oligarthrus. Only the first is found in Iraq, while E. multilocularis is rare (Kelly & Izzi 1959; Smyth 1968; Bonakdarpour 1967). T. echinococcus has a biphasic life-cycle living as an adult worm in the intestine of carnivorous animals such as dogs, foxes, cats, and wolves; in a larval cystic form it is found in the internal organs of herbivorous animals such as sheep, cows, and camels. Man may be infected in the same way as these animals - by swallowing the infective ova which are passed in the faeces of carnivores such as dogs. The embryo is liberated in the intestine, reaches the portal circulation and develops in the liver as a hydatid cyst. It may also enter the general circulation and thus reach the lungs and other parts of the body. Although the infection is acquired in early life, the symptoms of the disease may not appear until many years later (Babero et al. 1963a, b, c). The egg in its shell can survive in cold weather for six months; it can resist household antiseptics but will be killed by heating to 60°C for 45 seconds. One gramme of arecoline hydrobromide can eradicate the infection from dogs and should be repeated after three months (Blood et al. 1968). Two main types of cysts occur - the unilocular and the multilocular. The matured cyst wall is composed of three layers: (a) The outer layer formed by the host reaction is attached to the organ, such as the liver. (b) The thick middle layer called the laminated membrane is loosely attached to the outer layer and its thickness indicates the age of the cyst. (c) The inner or germinal layer adheres to the laminated membrane. It has the ability to produce brood capsules from which proscolices or tapeworm heads arise. Any dogs or other carni-
Fig. 1. Unruptured endocyst showing its attachments to the fibrous ectocyst by thin fibrin.
Fig.
2.
Shredsof endocyst with numerous daughter cysts.
vorous animals eating an infested organ or any food contaminated with these proscolices will become infected. Inside the cyst there is a clear fluid slightly alkaline in reaction. Some brood capsules separate from the wall of the cyst and clusters of proscolices in the fluid form the "hydatid sand"; small "daughter cysts" may sometimes be found between the adventitiallayer and the laminated membrane. The fluid inside the cyst is under pressure and as it increases it may lead to three events: (1) A solitary cyst in the liver grows to a size noticed by the patient himself, apart from producing various symptoms. (2) A solitary cyst remaining for some time encapsulated in the dense layer of the adventitia might be calcified; it will then be considered as a dead cyst and the body reactions will disappear.
Tropical Doctor, April I976
MANAGEMENT OF HYDATID DISEASE
I 71
Fig. 4. Hydatid cyst of the brain.
Fig. 3. Hydatid cyst of the breast.
(3) The cyst may rupture or slowly leak out. It may open into any coelomic cavity in the vicinity (peritoneum, pleura, pericardium, etc.). This leads to anaphylactic symptoms or even severe shock. Ifthe patient survives it, numerous hydatid cysts will be found in that cavity a few months later. It may connect with a hepatic vein and produce anaphylactic phenomena with lowering of the body immunity. The disseminated proscolices might be arrested in the long capillaries, . where they will form another cyst or cysts. They may also pass into the systemic circulation with the production of another one, or multiple cysts anywhere in the body. When the cyst opens on an epithelial surface (where the proscolices will not grow and the fluids will not be absorbed) other complications may occur. In cases of liver hydatid cyst it may open into a small hepatic biliary channel. The daughter cyst will then pass out through the duodenum or it may stop at the common bile duct and produce the obstructive jaundice. If
connected with the kidney it will be passed with the urine or produce renal colic, with obstruction. If connected with the lungs the cyst may pass into the bronchus and will be expectorated but if aspirated it may lead to pneumonia. The cystsmay adhere to the neighbouring structures like intestine, empty into the lumen, and this may lead to spontaneous cure; some cysts may even open to the outside as an abscess and if the content is expelled cure might follow. In general an opening of the cyst on the epithelial surfaces is not accompanied with anaphylactic reaction or any dissemination. DIAGNOSIS
The residential history of the patient is of the greatest importance in diagnosis and there is a saying in Iraq, "If you diagnose a lump anywhere in the body as hydatid disease you are 50% correct." Most cases are uncomplicated and the patient may notice accidentally a lump in the right hypochondrium (70% of cases). Anywhere else in the body the lump may be found on routine examination of the liver area or on mass X-ray surveys of the lungs, when older cysts will show up because of the calcified ectocyst. On physical examination the cyst presents as a tense rounded mass which becomes lobulated when attached to an organ. On percussion a thrill may be found (present in only 5% ofcasesbut more frequently when there are exogenous daughter cysts). Aspiration should never be performed when cysts are situated inside a cavity for fear of dissemination and anaphylactic reactions, but where the cysts are not in a cavity then these complications are rare. Ifby chance clear colourless fluid is obtained on aspiration
72
I MANAGEMENT OF HYDATID DISEASE
of a lump then one can be sure of a hydatid cyst and on microscopical examination proscolices or hooklets will be seen. Radioisotope scanning appropriate for each organ will. show the presence of a space-occupying lesion. Infected cysts cause only mild symptoms since the thick ectocyst acts as a barrier to the absorption of toxins and the local reaction is mild with a little tenderness and fever. When there is a leak into the endothelial lining there is an immediate anaphylactic reaction varying from simple urticaria to very severe shock which can kill the patient in hours; such shock must be treated with the utmost care by cortisone and blood transfusion. When shock has been dealt with immediate surgery is necessary. When the cyst leaks into an internal organ there are symptoms of obstruction with jaundice in the case of the liver or severe cough and expectoration in the case of the lungs. Examination of sputum, urine, or fluid leaking from the surface may show debris of the laminated membrane (like grape skins), proscolices, or hooklets, thus confirming the diagnosis. Cysts in the bone (osseous hydatid) can be found accidentally as a round space on X-ray or more likely as a pathogenic fracture. The general or systemic changes in the human host may be summarized as a slight rise in the eosinophil count to 8-10%, a positive complement fixation test (Weinberg reaction) and precipitin test. Skin hypersensitivity to its own antigen (Casoni skin test) is more specific than to Taenia saginaw antigens but with some, cross reactions may be due to other parasites (Ashley et al. 1972; Naji et al. 1973). TREATMENT
The germinal layer of a hydatid cyst is very sensitive to toxic drugs but the difficulty is how to make the drug penetrate the thick barrier of the adventitia and laminated membrane. Infection and calcification also kills the germinal layer but leaves behind an infected dead space that may need surgery. The basis of surgical treatment rests in uncomplicated cases upon three major points: (1) Evacuation of the contents of the cyst (endocystectomy with removal of the daughter cysts). (2) Avoidance of dissemination into a serous cavity. (3) Obliteration of the remaining cavity. Complete removal of the whole or part of the organ including the cyst is ideal and will satisfy all these three points, or the adventitia can be incised and the endocyst removed without rupturing (as in the lung, where by inflating with air the cyst can be expelled gradually).
Tropical Doctor, April I976
Fig. 5. Multiple hydatid cysts of the spleen.
If the cyst is not in a serous cavity such as in the muscle of the breast then it can be killed by the injection of 10 ml of 5% formalin and after a fiveminute period it should be emptied completely and washed out with saline. Even if the cyst is infected care must be taken not to leave any portion of the endocyst behind, since this will act as a foreign body and will discharge as a sinus which will not heal until the endocyst has been completely removed. When the cyst is inside a serous cavity and there is fear of dissemination, after opening the cavity and exposing the cyst, the field should be packed with gauze and the margin of it covered with small pieces of gauze soaked in 5°IcJ formalin. The cyst is then injected with 10 ml of 5% formalin and left for five minutes following which it is opened, the contents evacuated, the cavity washed with saline, and the adventitia closed. Any living proscolices will be killed by the formalin-soaked gauze and the large pack prevents absorption of the hydatid fluid and anaphylactic shock. If the cavity wall is thin it will collapse and be obliterated but if it is thick it is better to remove part of it and stitch the rest together from inside out so as to obliterate the cavity. When a cyst is calcified and cannot be removed in its entirety then it is better not to open or drain it otherwise it will remain draining for a long time. In the case of a complicated cyst opening on to an epithelial surface the cyst should be removed in toto with the organ (nephrectomy) or pan of an organ (lobectomy). In the liver it should be dealt with as in an uncomplicated case by cleaning the cavity and removing all parts of the endocyst which have caused bile duct obstruction leaving aT-tube behind.
Tropical Doctor, April I976 If the endocyst has been completely removed there is no need for drainage. In cases of rupture on to a serous or endothelial lining it is necessary to resuscitate the patient immediately and operate to evacuate the cyst, wash out the serous cavity (pleura, peritoneum) with acriflavine in water and close the ectocyst. Personally I have found that a good way to prevent dissemination in such cases (or in any other case where dissemination is suspected) is to give the patient antimony in fractional small doses such as are used in the treatment of schistosomiasis. With such treatment as prophylaxis I have not had any recurrences.
MANAGEMENT OF HYDATID DISEASE
I 73
REFERENCES
Ashley, J. S. A., et al, (1972). Lancet, 1, 890. Babero, B. B., and Al-Dabbagh, M. A. (1963a). J. Fac. Med. Baghdad, 5, 79 & 149. Babero, B. B., et al. (1963b). J. Fac. Med. Baghdad, 5, 8. Babero, B. B., et al. (1963c). Ann. trap. Med. Parasit., 57, 439. Blood, B. D., et al. (1968). Bull. WId Hlth Org., 39, 67. Bonakdarpour, A. (1967). Amer. J. Roentgenol., 99, 660. Kelly, T. D., and Izzi, N. (1959).J. Fac. Med. Baghdad, 1, 115. Naji, K., et al. (1973). Lancet, 1, 1518. Smyth, J. D. (1968). Bull. WId Hlth Org., 39, 5.
Book Review Health by the People (Geneva: World Health Organization, I975, pp. 206, Sw.Fr. ]6.) "Do it yourself" health care, or rather "let's do it together" health care, is the only possibility for many poor and isolated communities. Indeed, with a minimum of appropriate technical education and support, such a scheme achieves results which expensive professionalism could never provide. This book is the new gospel of the World Health Organization. It is illustrated by nine different services which vary in size from a locality to a national plan. Each one contains innovations and community participation. First countries are described where change in services was part of a gross political reorganization, as in China, Cuba, and Tanzania. Next are accounts of three areas in Iran, Niger, and Venezuela, where rural populations were under-served and special extensions of the existing health system are in progress. Finally, three physicians share their personal experience of local community development schemes in Guatemala, India, and Indonesia. Under their sensitive leadership the people set priorities, participated in programmes, and better health care was one of the consequences. "Primary health care" is a key phrase in the new approach, but it is nowhere specifically defined. One might imagine that this is what every mother does for her child, but by implication it is the first activity between a recognized health worker and the family when an individual falls ill. The trend is to use less highly trained helpers who are usually readily available because they are part of the community they serve. In the programmes part-time village health workers are said to be effective in managing and preventing common illnesses. This book is often inspiring, but contains some
community health jargon. Apparently many people have accepted the new health services, but little is known about the quality and effectiveness of care. Although a number of figures are quoted, there is no objective evaluation of changes in the health of some communities, especially in the smaller projects. It is also impossible to compare the cost of running these different schemes. The countries which were able to reorganize completely their systems for providing health care produced striking and rapid results due to radical changes in the way of life, strong leadership, and disciplined people. In the second group of projects like those in Iran and Niger, there is no dramatic change in the whole of society, but rather there are altered roles for existing health personnel and mobilization of people from the community to take additional responsibilities. In each of these localized programmes, the doctors possessed gifts of diplomacy, dedication, and patience. Though the potential of any community is considerable, the doubt remains that such schemes are largely dependent on an exceptional quality of leadership. The physicians concerned are certainly dynamic yet unobtrusive leaders whose epitaph could be in the words of the Chinese saying: "But of the best of leaders, when their task is accomplished, their work is done, the people all remark, we have done it ourselves." Doctors have recently been blamed for a "medical nemesis". Indeed, they have much to answer for because an obsession with medical excellence has sometimes diverted resources and deprived the poor of any care at all. This important volume describes not only models of how people can help themselves to better health, but also examples of physicians who are "demythologizing medicine". w. A. M. CUTTING
Tropical Doctor, April I976
Management of hydatid disease Khalid Naji, MS Professor of Surgery, Medical College, Baghdad, Iraq
TROPICAL DOCTOR
1976, 6, 70-73
Hydatid disease has a long history. It is referred to in the Talmud as "water bladder". Hippocrates mentioned it in his Aphorisms and Al-Rhazi referred to it in describing the diseases of the liver. Rudolphi gave it the name of vesicular echinococcosis in 1808 although Francesco Redi recognized it in animals in the seventeenth century. Leuckart described the cycle of development of this helminth in 1886. This disease can be caused by anyone of several species of the genus Taenia echinococcus - Echinococcus granulosus, E. multilocularis, E. oligarthrus. Only the first is found in Iraq, while E. multilocularis is rare (Kelly & Izzi 1959; Smyth 1968; Bonakdarpour 1967). T. echinococcus has a biphasic life-cycle living as an adult worm in the intestine of carnivorous animals such as dogs, foxes, cats, and wolves; in a larval cystic form it is found in the internal organs of herbivorous animals such as sheep, cows, and camels. Man may be infected in the same way as these animals - by swallowing the infective ova which are passed in the faeces of carnivores such as dogs. The embryo is liberated in the intestine, reaches the portal circulation and develops in the liver as a hydatid cyst. It may also enter the general circulation and thus reach the lungs and other parts of the body. Although the infection is acquired in early life, the symptoms of the disease may not appear until many years later (Babero et al. 1963a, b, c). The egg in its shell can survive in cold weather for six months; it can resist household antiseptics but will be killed by heating to 60°C for 45 seconds. One gramme of arecoline hydrobromide can eradicate the infection from dogs and should be repeated after three months (Blood et al. 1968). Two main types of cysts occur - the unilocular and the multilocular. The matured cyst wall is composed of three layers: (a) The outer layer formed by the host reaction is attached to the organ, such as the liver. (b) The thick middle layer called the laminated membrane is loosely attached to the outer layer and its thickness indicates the age of the cyst. (c) The inner or germinal layer adheres to the laminated membrane. It has the ability to produce brood capsules from which proscolices or tapeworm heads arise. Any dogs or other carni-
Fig. 1. Unruptured endocyst showing its attachments to the fibrous ectocyst by thin fibrin.
Fig.
2.
Shredsof endocyst with numerous daughter cysts.
vorous animals eating an infested organ or any food contaminated with these proscolices will become infected. Inside the cyst there is a clear fluid slightly alkaline in reaction. Some brood capsules separate from the wall of the cyst and clusters of proscolices in the fluid form the "hydatid sand"; small "daughter cysts" may sometimes be found between the adventitiallayer and the laminated membrane. The fluid inside the cyst is under pressure and as it increases it may lead to three events: (1) A solitary cyst in the liver grows to a size noticed by the patient himself, apart from producing various symptoms. (2) A solitary cyst remaining for some time encapsulated in the dense layer of the adventitia might be calcified; it will then be considered as a dead cyst and the body reactions will disappear.
Tropical Doctor, April I976
MANAGEMENT OF HYDATID DISEASE
I 71
Fig. 4. Hydatid cyst of the brain.
Fig. 3. Hydatid cyst of the breast.
(3) The cyst may rupture or slowly leak out. It may open into any coelomic cavity in the vicinity (peritoneum, pleura, pericardium, etc.). This leads to anaphylactic symptoms or even severe shock. Ifthe patient survives it, numerous hydatid cysts will be found in that cavity a few months later. It may connect with a hepatic vein and produce anaphylactic phenomena with lowering of the body immunity. The disseminated proscolices might be arrested in the long capillaries, . where they will form another cyst or cysts. They may also pass into the systemic circulation with the production of another one, or multiple cysts anywhere in the body. When the cyst opens on an epithelial surface (where the proscolices will not grow and the fluids will not be absorbed) other complications may occur. In cases of liver hydatid cyst it may open into a small hepatic biliary channel. The daughter cyst will then pass out through the duodenum or it may stop at the common bile duct and produce the obstructive jaundice. If
connected with the kidney it will be passed with the urine or produce renal colic, with obstruction. If connected with the lungs the cyst may pass into the bronchus and will be expectorated but if aspirated it may lead to pneumonia. The cystsmay adhere to the neighbouring structures like intestine, empty into the lumen, and this may lead to spontaneous cure; some cysts may even open to the outside as an abscess and if the content is expelled cure might follow. In general an opening of the cyst on the epithelial surfaces is not accompanied with anaphylactic reaction or any dissemination. DIAGNOSIS
The residential history of the patient is of the greatest importance in diagnosis and there is a saying in Iraq, "If you diagnose a lump anywhere in the body as hydatid disease you are 50% correct." Most cases are uncomplicated and the patient may notice accidentally a lump in the right hypochondrium (70% of cases). Anywhere else in the body the lump may be found on routine examination of the liver area or on mass X-ray surveys of the lungs, when older cysts will show up because of the calcified ectocyst. On physical examination the cyst presents as a tense rounded mass which becomes lobulated when attached to an organ. On percussion a thrill may be found (present in only 5% ofcasesbut more frequently when there are exogenous daughter cysts). Aspiration should never be performed when cysts are situated inside a cavity for fear of dissemination and anaphylactic reactions, but where the cysts are not in a cavity then these complications are rare. Ifby chance clear colourless fluid is obtained on aspiration
72
I MANAGEMENT OF HYDATID DISEASE
of a lump then one can be sure of a hydatid cyst and on microscopical examination proscolices or hooklets will be seen. Radioisotope scanning appropriate for each organ will. show the presence of a space-occupying lesion. Infected cysts cause only mild symptoms since the thick ectocyst acts as a barrier to the absorption of toxins and the local reaction is mild with a little tenderness and fever. When there is a leak into the endothelial lining there is an immediate anaphylactic reaction varying from simple urticaria to very severe shock which can kill the patient in hours; such shock must be treated with the utmost care by cortisone and blood transfusion. When shock has been dealt with immediate surgery is necessary. When the cyst leaks into an internal organ there are symptoms of obstruction with jaundice in the case of the liver or severe cough and expectoration in the case of the lungs. Examination of sputum, urine, or fluid leaking from the surface may show debris of the laminated membrane (like grape skins), proscolices, or hooklets, thus confirming the diagnosis. Cysts in the bone (osseous hydatid) can be found accidentally as a round space on X-ray or more likely as a pathogenic fracture. The general or systemic changes in the human host may be summarized as a slight rise in the eosinophil count to 8-10%, a positive complement fixation test (Weinberg reaction) and precipitin test. Skin hypersensitivity to its own antigen (Casoni skin test) is more specific than to Taenia saginaw antigens but with some, cross reactions may be due to other parasites (Ashley et al. 1972; Naji et al. 1973). TREATMENT
The germinal layer of a hydatid cyst is very sensitive to toxic drugs but the difficulty is how to make the drug penetrate the thick barrier of the adventitia and laminated membrane. Infection and calcification also kills the germinal layer but leaves behind an infected dead space that may need surgery. The basis of surgical treatment rests in uncomplicated cases upon three major points: (1) Evacuation of the contents of the cyst (endocystectomy with removal of the daughter cysts). (2) Avoidance of dissemination into a serous cavity. (3) Obliteration of the remaining cavity. Complete removal of the whole or part of the organ including the cyst is ideal and will satisfy all these three points, or the adventitia can be incised and the endocyst removed without rupturing (as in the lung, where by inflating with air the cyst can be expelled gradually).
Tropical Doctor, April I976
Fig. 5. Multiple hydatid cysts of the spleen.
If the cyst is not in a serous cavity such as in the muscle of the breast then it can be killed by the injection of 10 ml of 5% formalin and after a fiveminute period it should be emptied completely and washed out with saline. Even if the cyst is infected care must be taken not to leave any portion of the endocyst behind, since this will act as a foreign body and will discharge as a sinus which will not heal until the endocyst has been completely removed. When the cyst is inside a serous cavity and there is fear of dissemination, after opening the cavity and exposing the cyst, the field should be packed with gauze and the margin of it covered with small pieces of gauze soaked in 5°IcJ formalin. The cyst is then injected with 10 ml of 5% formalin and left for five minutes following which it is opened, the contents evacuated, the cavity washed with saline, and the adventitia closed. Any living proscolices will be killed by the formalin-soaked gauze and the large pack prevents absorption of the hydatid fluid and anaphylactic shock. If the cavity wall is thin it will collapse and be obliterated but if it is thick it is better to remove part of it and stitch the rest together from inside out so as to obliterate the cavity. When a cyst is calcified and cannot be removed in its entirety then it is better not to open or drain it otherwise it will remain draining for a long time. In the case of a complicated cyst opening on to an epithelial surface the cyst should be removed in toto with the organ (nephrectomy) or pan of an organ (lobectomy). In the liver it should be dealt with as in an uncomplicated case by cleaning the cavity and removing all parts of the endocyst which have caused bile duct obstruction leaving aT-tube behind.
Tropical Doctor, April I976 If the endocyst has been completely removed there is no need for drainage. In cases of rupture on to a serous or endothelial lining it is necessary to resuscitate the patient immediately and operate to evacuate the cyst, wash out the serous cavity (pleura, peritoneum) with acriflavine in water and close the ectocyst. Personally I have found that a good way to prevent dissemination in such cases (or in any other case where dissemination is suspected) is to give the patient antimony in fractional small doses such as are used in the treatment of schistosomiasis. With such treatment as prophylaxis I have not had any recurrences.
MANAGEMENT OF HYDATID DISEASE
I 73
REFERENCES
Ashley, J. S. A., et al, (1972). Lancet, 1, 890. Babero, B. B., and Al-Dabbagh, M. A. (1963a). J. Fac. Med. Baghdad, 5, 79 & 149. Babero, B. B., et al. (1963b). J. Fac. Med. Baghdad, 5, 8. Babero, B. B., et al. (1963c). Ann. trap. Med. Parasit., 57, 439. Blood, B. D., et al. (1968). Bull. WId Hlth Org., 39, 67. Bonakdarpour, A. (1967). Amer. J. Roentgenol., 99, 660. Kelly, T. D., and Izzi, N. (1959).J. Fac. Med. Baghdad, 1, 115. Naji, K., et al. (1973). Lancet, 1, 1518. Smyth, J. D. (1968). Bull. WId Hlth Org., 39, 5.
Book Review Health by the People (Geneva: World Health Organization, I975, pp. 206, Sw.Fr. ]6.) "Do it yourself" health care, or rather "let's do it together" health care, is the only possibility for many poor and isolated communities. Indeed, with a minimum of appropriate technical education and support, such a scheme achieves results which expensive professionalism could never provide. This book is the new gospel of the World Health Organization. It is illustrated by nine different services which vary in size from a locality to a national plan. Each one contains innovations and community participation. First countries are described where change in services was part of a gross political reorganization, as in China, Cuba, and Tanzania. Next are accounts of three areas in Iran, Niger, and Venezuela, where rural populations were under-served and special extensions of the existing health system are in progress. Finally, three physicians share their personal experience of local community development schemes in Guatemala, India, and Indonesia. Under their sensitive leadership the people set priorities, participated in programmes, and better health care was one of the consequences. "Primary health care" is a key phrase in the new approach, but it is nowhere specifically defined. One might imagine that this is what every mother does for her child, but by implication it is the first activity between a recognized health worker and the family when an individual falls ill. The trend is to use less highly trained helpers who are usually readily available because they are part of the community they serve. In the programmes part-time village health workers are said to be effective in managing and preventing common illnesses. This book is often inspiring, but contains some
community health jargon. Apparently many people have accepted the new health services, but little is known about the quality and effectiveness of care. Although a number of figures are quoted, there is no objective evaluation of changes in the health of some communities, especially in the smaller projects. It is also impossible to compare the cost of running these different schemes. The countries which were able to reorganize completely their systems for providing health care produced striking and rapid results due to radical changes in the way of life, strong leadership, and disciplined people. In the second group of projects like those in Iran and Niger, there is no dramatic change in the whole of society, but rather there are altered roles for existing health personnel and mobilization of people from the community to take additional responsibilities. In each of these localized programmes, the doctors possessed gifts of diplomacy, dedication, and patience. Though the potential of any community is considerable, the doubt remains that such schemes are largely dependent on an exceptional quality of leadership. The physicians concerned are certainly dynamic yet unobtrusive leaders whose epitaph could be in the words of the Chinese saying: "But of the best of leaders, when their task is accomplished, their work is done, the people all remark, we have done it ourselves." Doctors have recently been blamed for a "medical nemesis". Indeed, they have much to answer for because an obsession with medical excellence has sometimes diverted resources and deprived the poor of any care at all. This important volume describes not only models of how people can help themselves to better health, but also examples of physicians who are "demythologizing medicine". w. A. M. CUTTING
