575

administered examinations of achievement and intellectualfunction. Had our patient been reported at age 3, he wouldhave been evidence for the association of mental retardationand thymic aplasia. From this case, it seems that the delayeddevelopment is a function of the repeated insults rather thanthe underlying disorder. Obviously more data are requiredbefore any reliable conclusions may be drawn.

W. EDWIN DODSONDUANE ALEXANDERMATTI AL-AISHFELIX DE LA CRUZ.

Children’s Diagnostic and Study Branch,National Institute of Child Health,

and Human Development,National Institutes of Health,Bethesda, Maryland 20014.

WHERE ARE THE TEACHERS OF

COMMUNITY MEDICINE?

SIR,-Many words used by doctors lend themselves to

different interpretation. Social medicine, community medicine-even the word medicine itself-can all have different mean-ings in different contexts. I should therefore like to putanother point of view apart from the one expressed by ProfessorMcKeown (March 1, p. 463). The shortage of teachers

(particularly in the London schools), which was the maintheme of the paper by Professor Morris and Dr. Warren (Feb. 1,p. 249), is acknowledged by all who are close to this field, but itreceives scant attention from others who play an importantpart in undergraduate education. One reason may be the

uncertainty that exists in the minds of some physicians andsurgeons about the meaning of social medicine and the con-fusion between it and medical social work. Furthermore, eventhough most teachers of the subject have, as Professor McKeownsaid, a reasonably consistent idea of what they mean by socialmedicine, it should be pointed out that this consistency is notfound in the variety of titles which are used to describe theappropriate departments of the different medical schools inBritain.

Recently, teaching hospitals, some of which tended to bealoof from the communities in which they were situated, haveaccepted responsibility for providing specialist and otherservices for their local populations, and thus serve their com-munities. This breach of the ramparts surrounding the ivorytowers was an important step towards ending the demarcationbetween " hospital " and " community ". Against this back-ground it seems that the term " community medicine " can beapplied to that department of a medical school where certainacademic disciplines are based. A community-medicine depart-ment should be concerned with teaching and research in threebroad areas: epidemiology and biostatistics; preventive medicine,including health education, with particular reference to com-munities ; organisation of medical care, consisting of two

components-(a) health and related services and their changingstructures, functions, and interrelationships, and (b) the inter-action between society (including family, home, and work), thepatient, and his illness. Some parts of these subdivisions areincluded in the general teaching of medicine itself, and adepartment of community medicine should not assume a

monopoly position but should collaborate with teachers inmany fields, especially those giving clinical services.The term *’ community medicine " may seem ambiguous at

present, but, with the trend towards a new interpretation of" hospital and community ", it seems reasonable to expectthat its use to mean " the specialty practised by epidemiologistsand by administrators of medical services-e.g., medical officersof local authorities, central health or other government depart-ments, hospital boards or industries-and by the staffs of thecorresponding academic departments " may receive generalrecognition. Under these circumstances this definition shouldcover the study of health and related services for communities-including inpatient services.

J. A. D. ANDERSON.Guy’s Hospital Medical School,

London S.E.1.

1. Royal Commission on Medical Education 1965-68. Report; para. 133.H.M. Stationery Office, 1968.

COXSACKIE A7 VIRUS AND POLIOMYELITISIN VACCINEES

SIR,-Dr. Kitamura and colleagues (March 1, p. 465)remind us of the problems of interpretation of poliomyelitisdeveloping after poliovirus vaccination. Their communication,like that of Stolley et al.l reporting poliomyelitis after contactwith a vaccinee, illustrates the variety of laboratory investiga-tions required in such cases and shows some of the difficultiesof interpretation which may arise.Now that poliomyelitis due to virulent " wild " poliovirus

has become unusual, it is appropriate in such cases to attemptto exclude infection with Coxsackie A7 virus, the next mostimportant enterovirus causing paralysis. Because routinetissue-cultures usually fail to detect this virus, its isolationrequires inoculation of newborn mice, as in one of the abovereported cases.l Several serological tests for antibodies to

Coxsackie A7 virus are available,2 but for routine purposes it isconvenient to include the tissue-culture-adapted strain,3 withthe battery of polioviruses in the neutralisation tests. By thesemethods Coxsackie A7 infection was found in the Glasgow areain cases of paralytic disease developing shortly after administra-tion of inactivated 4 and live oral 2 poliovaccine.

It is comforting to note that Coxsackie A7 virus has shownno tendency to become more prevalent in this area since theepidemic of 1959.4 Since the outbreak of 1963 2 it has beenisolated in this laboratory from only 9 children in 1967 and1 child in 1968 (5 boys and 5 girls: 2 aged under one year,2 aged two years, and 1 each aged three, four, five, six, seven,and twelve years). None was paralysed; 9 had aseptic meningitis(1 complicated by acute ataxia) and 1 whooping cough.

N. R. GRIST.

Glasgow University Departmentof Infectious Diseases,

Ruchill Hospital,Glasgow N.W.

BLOOD-POTASSIUM IN PATIENTS UNDERGOINGHÆMODIALYSIS

SiR,—The correspondence in your columns between Dr.Boucher and Dr. Strunin (Jan. 4, p. 55), Dr. Seedat (Jan. 11,p. 104), and Mr. Ram and Mr. Chisholm (Feb. 1, p. 260), hasprompted these comments.Most investigators interested in the area of carbohydrate

metabolism and potassium have long since agreed that there isno correlation between levels of serum and total-body potas-sium. We thank Dr. Seedat 5 for confirming our publisheddata that patients with chronic urasmia have decreased levelsof total exchangeable body potassium. We have also pointedout that abnormalities of carbohydrate metabolism in suchpatients are due to the delayed release of pancreatic insulin,which is potassium-dependent. With the return of values fortotal-body potassium to normal, insulin release occurs earlierin time and in greater amounts, and carbohydrate metabolismreturns towards normal.

Other data from our laboratory, as yet unpublished, showthat the disappearance-rate of glucose from the plasma ofpatients undergoing chronic hsmodialysis is dependent uponthe concentration of potassium used in the dialysate, regardlessof the level of the patient’s serum-potassium. The higherthe concentration of potassium used in the dialysate, the morerapid is the glucose-disappearance rate. The reverse is true ifthe potassium concentration is low. All patients studied hadlow total-body-potassium values and all had hyperkalaemia.Manipulations of dialysate concentrations of urea did not, perse, affect glucose-disappearance rates.1. Stolley, P. D., Joseph, J. M.. Allen, J. C., Deane, G., Janney, J. H.

Lancet, 1968, i, 661.2. Grist, N. R. ibid. 1965, ii, 261.3. Habel, K., Loomis, L. N. Proc. Soc. exp. Biol. Med. 1957, 95, 597.4. Combined Scottish Study. Br. med. J. 1961, ii, 597.5. Seedat, Y. K. Lancet, 1968, ii, 1166.6. Spergel, G., Bleicher, S. J., Goldberg, M., Adesman, J., Goldner, M. G.

Metabolism, 1967, 16, 581.