- Email: [email protected]
MILKBORNE BRUCELLA ABORTUS INFECTION
110 to reply, or had died, had had a general practitioners asked about the laminectomy? result of the operation, or the cause of death? The Queen Square group assumes that the results for the 20 patients based on their general practitioners’ responses to a questionnaire were comparable with those based on personal assessment by Dr Thomas. Can they justify this assumption? Mr Grant’s results seem impressive enough to deserve better
DUCTOGRAPHY FOR NIPPLE DISCHARGE
of the patients who failed Were their
analysis. Charing Cross Hospital Medical School,
A. HERXHEIMER
London W6 8RF
SIR,-The Queen Square workers conclude from their study that surgery is more appropriate than no surgery for their patients with low back pain and sciatica. I fail to see how they can arrive at this conclusion from the data presented. The basis for the selection of group A patients for operation is not clear. Did group B patients have a normal myelogram or no abnormal neurological signs, or did the surgeon feel they were unsuitable for operation for other reasons? The male-female sex ratio of the two groups is different (group A 166:1, group B 1’1:1). The females of group B have an older age distribution than those of group A. We are given some details of the physical signs found; for example, 66 patients of the 86 group A patients had a limited straight leg raise, of whom 76% had a good result, whilst only 50% of an unknown number of group B patients with a limited straight leg raise had a good result. Is this 1 of 2 patients or 16 of 32 group B patients? The use of group B patients as controls for group A seems unreasonable, and the use of a chi-square test is invalid. We are not told how long these patients were followed-up, although it is well known that a short follow-up in this condition is unreliable; nor are we given any details of their final assessment. How is the outcome of an operation on a patient aged "30 years and below" compared with that on a patient aged "over 70 years"? The only study that I am aware of which has been able to demonstrate the early advantages of surgery in sciatica is Weber’s,1 and he was able to demonstrate an advantage for operated over unoperated patients in the first postoperative year only; there was an insignificant advantage at four years and none at ten years of follow-up. W. J. Kane (Chicago) has demonstrated the enormous geographical variation in the incidence of laminectomy, and Britain has one of the lowest incidences of this procedure (8’0operations per 100 000 population per year) (personal communication). I hope that this paper does not push us unnecessarily towards the figure found on the west coast of the United States (88’88 operations per 100 000 population per year). Orthopaedic Department, St Bartholomew’s Hospital,
J. C. T. FAIRBANK
London EC1A 7BE
***These letters have
been shown
to
Professor Marshall, whose
reply follows.-ED. L. SIR,-The 135 patients were a consecutive series seen by me. The laminectomies were done over a period of 7 years, the technique being as described in the paper for all cases. The duration of followranged from 8 years to 1 year. Nine of the patients who failed to reply or had died had had a laminectomy. The general practitioners gave satisfactory responses to questions about further periods of back pain and loss of time from work. The unoperated group B was reported, not as a control (which it clearly was not), but to provide a complete picture of the clinical experience of one physician and up
SIR,-Nipple discharge can be difficult to manage. The indications for exploration of the breast and the method for doing this are poorly defined. The comments on management in your Dec 17 editorial are of little help to the surgeon. As much preoperative information as possible is useful, and for this reason we always request contrast xeroradiography (ductography) in addition to routine xeroradiography in uniductal nipple discharge. This investigation is simple and helpful but it is not popular among breast surgeons, despite the fact that it frequently reveals the cause of the discharge, helps the clinician to decide if exploration is necessary, and always gives the position in the duct of any intraductal lesion requiring excisional biopsy. Over a four year period we saw 90 patients with nipple discharge, this being 4% of the attendances at our breast clinic. 59 ductographies were done and 34 microdochectomies were the result. As a consequence 5 cases of carcinoma-in-situ and 1 of invasive carcinoma were diagnosed. Routine clinical and radiological examinations had not revealed evidence of malignant disease in these 6 patients. The 25 patients on whom no biopsy was done show no evidence of malignancy, over an average follow-up period of eighteen months. Ductography should be more widely practised; it certainly helps in the management of nipple discharge. St Luke’s Hospital, Huddersfield HD4 5RH
MILKBORNE BRUCELLA ABORTUS INFECTION to comment on your conclusion (Nov 19, that human milkborne infection with Brucella abortus is rare. This has certainly been true in England and Wales since eradication in cattle in the 1970s-for example, in laboratory reports for the years 1978-82, only 4 of 99 reported infections were thought 1 to have been associated with milk. We are, however, not convinced that milkborne infection was rare in the years before eradication. Dalrymple-Champneys estimated that there were at least 500 new cases of human brucellosis each year in England and Wales and about 70% of these acquired the infection from milk. This proportion came from his study of cases reported to him between 1928 and 1957; of 1255 cases 885 had probably acquired the infection from milk or cream.2Although Boycott3 pointed out that some of the cases were farmers and were not necessarily infected by the raw milk they drank, these 885 cases were apparently not occupationally exposed to cattle. DalrympleChampneys excluded 147 cases from the group of possible milkborne cases because "there had been actual or possible contact with infected animals or their excretions". The failure of human brucellosis to fall in incidence as pasteurisation of milkbecame more widespread in England and Walesand the increase in Irelands do not necessarily mean that the disease was not milkborne, as you point out. These trends may have been associated with increasing recognition and reporting of the disease and to changes in dairying practice. We believe these factors have played a part in a reported increase in the milkborne spread of another infection derived from cattle, salmonellosis, in the past 30 5 years despite increasing pasteurisation. We agree that the age and sex distribution of brucellosis is unlike that in most milkborne infections but we do not think this justifies the conclusion that milkborne infection was rare in the years before eradication in cattle began. N. S. GALBRAITH PHLS Communicable Disease Surveillance Centre, London NW9 5EQ JENNIFER J. PUSEY
SIR,-We should like
p
1180)
surgeon in the routine management of a common, much debated condition.
1. Galbraith
University Department of Clinical Neurology, National Hospital,
2.
London WC1N 3BG
JOHN MARSHALL study with
ten
years of
NS, Pusey JJ. Milkborne infectious disease in England and Wales 1938 to DLJ, ed. Proceedings of Symposium on the Hazards of Milk. (in
1982. In: Freed
3. 4.
1. Weber H. Lumbar disc herniation: a controlled, prospective observation Spine 1983; 8: 131-40.
W. GRAHAM HARRIS
press). Dalrymple-Champneys W. Brucella infection and undulant fever in man. London: Oxford University Press, 1960: 36. Boycott JA, Undulant fever as an occupational disease. Lancet 1964; i: 972-73 Flynn MP. Human clinical bovine-type brucellosis not derived from milk. Publ Health (Lond) 1983; 97: 149-57. NS, Forbes P, Clifford C. Communicable disease associated with milk and dairy products in England and Wales 1951-80. Br Med J 1982; 284: 1761-65
5. Galbraith
DUCTOGRAPHY FOR NIPPLE DISCHARGE
of the patients who failed Were their
analysis. Charing Cross Hospital Medical School,
A. HERXHEIMER
London W6 8RF
SIR,-The Queen Square workers conclude from their study that surgery is more appropriate than no surgery for their patients with low back pain and sciatica. I fail to see how they can arrive at this conclusion from the data presented. The basis for the selection of group A patients for operation is not clear. Did group B patients have a normal myelogram or no abnormal neurological signs, or did the surgeon feel they were unsuitable for operation for other reasons? The male-female sex ratio of the two groups is different (group A 166:1, group B 1’1:1). The females of group B have an older age distribution than those of group A. We are given some details of the physical signs found; for example, 66 patients of the 86 group A patients had a limited straight leg raise, of whom 76% had a good result, whilst only 50% of an unknown number of group B patients with a limited straight leg raise had a good result. Is this 1 of 2 patients or 16 of 32 group B patients? The use of group B patients as controls for group A seems unreasonable, and the use of a chi-square test is invalid. We are not told how long these patients were followed-up, although it is well known that a short follow-up in this condition is unreliable; nor are we given any details of their final assessment. How is the outcome of an operation on a patient aged "30 years and below" compared with that on a patient aged "over 70 years"? The only study that I am aware of which has been able to demonstrate the early advantages of surgery in sciatica is Weber’s,1 and he was able to demonstrate an advantage for operated over unoperated patients in the first postoperative year only; there was an insignificant advantage at four years and none at ten years of follow-up. W. J. Kane (Chicago) has demonstrated the enormous geographical variation in the incidence of laminectomy, and Britain has one of the lowest incidences of this procedure (8’0operations per 100 000 population per year) (personal communication). I hope that this paper does not push us unnecessarily towards the figure found on the west coast of the United States (88’88 operations per 100 000 population per year). Orthopaedic Department, St Bartholomew’s Hospital,
J. C. T. FAIRBANK
London EC1A 7BE
***These letters have
been shown
to
Professor Marshall, whose
reply follows.-ED. L. SIR,-The 135 patients were a consecutive series seen by me. The laminectomies were done over a period of 7 years, the technique being as described in the paper for all cases. The duration of followranged from 8 years to 1 year. Nine of the patients who failed to reply or had died had had a laminectomy. The general practitioners gave satisfactory responses to questions about further periods of back pain and loss of time from work. The unoperated group B was reported, not as a control (which it clearly was not), but to provide a complete picture of the clinical experience of one physician and up
SIR,-Nipple discharge can be difficult to manage. The indications for exploration of the breast and the method for doing this are poorly defined. The comments on management in your Dec 17 editorial are of little help to the surgeon. As much preoperative information as possible is useful, and for this reason we always request contrast xeroradiography (ductography) in addition to routine xeroradiography in uniductal nipple discharge. This investigation is simple and helpful but it is not popular among breast surgeons, despite the fact that it frequently reveals the cause of the discharge, helps the clinician to decide if exploration is necessary, and always gives the position in the duct of any intraductal lesion requiring excisional biopsy. Over a four year period we saw 90 patients with nipple discharge, this being 4% of the attendances at our breast clinic. 59 ductographies were done and 34 microdochectomies were the result. As a consequence 5 cases of carcinoma-in-situ and 1 of invasive carcinoma were diagnosed. Routine clinical and radiological examinations had not revealed evidence of malignant disease in these 6 patients. The 25 patients on whom no biopsy was done show no evidence of malignancy, over an average follow-up period of eighteen months. Ductography should be more widely practised; it certainly helps in the management of nipple discharge. St Luke’s Hospital, Huddersfield HD4 5RH
MILKBORNE BRUCELLA ABORTUS INFECTION to comment on your conclusion (Nov 19, that human milkborne infection with Brucella abortus is rare. This has certainly been true in England and Wales since eradication in cattle in the 1970s-for example, in laboratory reports for the years 1978-82, only 4 of 99 reported infections were thought 1 to have been associated with milk. We are, however, not convinced that milkborne infection was rare in the years before eradication. Dalrymple-Champneys estimated that there were at least 500 new cases of human brucellosis each year in England and Wales and about 70% of these acquired the infection from milk. This proportion came from his study of cases reported to him between 1928 and 1957; of 1255 cases 885 had probably acquired the infection from milk or cream.2Although Boycott3 pointed out that some of the cases were farmers and were not necessarily infected by the raw milk they drank, these 885 cases were apparently not occupationally exposed to cattle. DalrympleChampneys excluded 147 cases from the group of possible milkborne cases because "there had been actual or possible contact with infected animals or their excretions". The failure of human brucellosis to fall in incidence as pasteurisation of milkbecame more widespread in England and Walesand the increase in Irelands do not necessarily mean that the disease was not milkborne, as you point out. These trends may have been associated with increasing recognition and reporting of the disease and to changes in dairying practice. We believe these factors have played a part in a reported increase in the milkborne spread of another infection derived from cattle, salmonellosis, in the past 30 5 years despite increasing pasteurisation. We agree that the age and sex distribution of brucellosis is unlike that in most milkborne infections but we do not think this justifies the conclusion that milkborne infection was rare in the years before eradication in cattle began. N. S. GALBRAITH PHLS Communicable Disease Surveillance Centre, London NW9 5EQ JENNIFER J. PUSEY
SIR,-We should like
p
1180)
surgeon in the routine management of a common, much debated condition.
1. Galbraith
University Department of Clinical Neurology, National Hospital,
2.
London WC1N 3BG
JOHN MARSHALL study with
ten
years of
NS, Pusey JJ. Milkborne infectious disease in England and Wales 1938 to DLJ, ed. Proceedings of Symposium on the Hazards of Milk. (in
1982. In: Freed
3. 4.
1. Weber H. Lumbar disc herniation: a controlled, prospective observation Spine 1983; 8: 131-40.
W. GRAHAM HARRIS
press). Dalrymple-Champneys W. Brucella infection and undulant fever in man. London: Oxford University Press, 1960: 36. Boycott JA, Undulant fever as an occupational disease. Lancet 1964; i: 972-73 Flynn MP. Human clinical bovine-type brucellosis not derived from milk. Publ Health (Lond) 1983; 97: 149-57. NS, Forbes P, Clifford C. Communicable disease associated with milk and dairy products in England and Wales 1951-80. Br Med J 1982; 284: 1761-65
5. Galbraith