840

was obviously an aneurysmal dilatation of theabdominal aorta, and consisted of a sacculation ofthe posterior wall of the vessel (Fig. 2). In shape theaneurysm was roughly spherical, with a mean

diameter of 5! in. The lower margin of theorifice of the aneurysm was situated some 3 in.above the level of the lst lumbar vertebra, butthe sac itself extended as low as the body of thatvertebra, thus displacing anteriorly the intact portionof the aorta. Above, the aneurysm was adherent tothe central portion of the diaphragm and appearedto extend as far as the upper limit of the abdominalportion of the vessel. The inner surfaces of boththe undilated portion of the aorta and the aneurysmshowed numerous atheromatous and syphiliticplaques.

Dissection of the back revealed a large quantity oflaminated blood clot penetrating into the spinalcord, with much erosion of the bodies of the lowestthree dorsal vertebrae. The destruction was worst inthe llth dorsal vertebra, but there was no actualcollapse of the column.The spinal cord in the region of the vertebral

erosion was embedded in blood clot, and on removalrevealed an extensive destruction of the anteriorportion of the lowest 3 in. of the cord itself andof the uppermost inch of the cauda equina. The

damage was greatest at the centre of this area andaccounted for almost half the depth of the cord.Sections of the cord taken It in. above the erosionshowed a complete bilateral degeneration of the

posterior columns, and slight degree of peripheraldegeneration in both postero-lateral areas. Selectivestaining demonstrated that much of this whitematter degeneration was of fairly recent origin.

Histopathological examination of the brain con-firmed the clinical diagnosis of G.P.I.

The two main features of interest in this patientwere the long duration of the history and the asso-ciation of the aneurysm with general paralysis ofthe insane.

We wish to thank the Brompton Hospital, theNational Hospital for Diseases of the Heart, and theMiddlesex Hospital for supplying us with such exactdetails of the patient’s earlier signs and symptoms,thus making possible a complete and accurate clinicalhistory extending over many years. We are alsograteful to the Middlesex Hospital for allowing us toreproduce the radiogram.

REFERENCE

Kampmeier, R. H. (1936) Amer. J. med. Sci. 192, 97.

MEDICAL SOCIETIES

SOCIETY OF MEDICAL OFFICERS OF

HEALTH

AT a meeting of the fever hospital medical servicegroup of this society, held on March 25th, with thepresident, Dr. J. A. H. BRINCKER in the chair, adiscussion on the spread of

Streptococcal Infection as Ascertained by TypeDetermination

was opened by Dr. V. D. ALLISON (Ministry of HealthPathological Laboratory), who described the classifica-tion of haemolytic streptococci into groups by Lance-field’s precipitation method, the importance of

Group A in human disease, and the identificationwithin this group by Griffith of some 26 serologicaltypes by means of specific agglutinating sera. The

multiplicity of types was, he said, of real help intracing the sources and paths of spread of infection,while group classification was of little value as itdid not exonerate from suspicion those who mightbe harbouring Group A type other than the typeresponsible for the outbreak. The main value oftype determination in infections caused by Str.pyogenes was, he said, to be found in two directions :-

(1) The investigation of the source and paths ofinfection in explosive outbreaks of streptococcalinfection due, for example, to milk and in outbreaksof puerperal fever in maternity homes and hospitals.

(2) The investigation of the paths of spread ofinfection in the wards of general and fever hospitals,and the effects of reinfection °and cross-infectionas the cause of grave complications.The advantages of type determination had beenwell exemplified in many explosive outbreaks of

streptococcal infection, some of major importance,during the last few years, for example, the out-breaks caused by milk infected with Str. pyogenesat Denham, Chelmsford, and Doncaster, where ineach case the source of infection had been definitelyestablished. In numerous outbreaks of puerperalfever the identification of the infecting strain hadgiven a clue leading to the discovery of the source

of infection. In his own experience, said Dr. Allison,epidemiological investigations of streptococcal infec-tions in multiple-bed scarlet fever wards and incubicles had shown conclusively that-

(1) Patients nursed throughout their illness incubicles or chambers show no change of the sero-

logical type of the infecting streptococcus. Segrega-tion of patients in small wards according to the sero-logical type of the infecting streptococcus showed thatif a change of type occurred, it was due to the intro-duction of fresh infection by a member of the wardstaff.

(2) Infection with one serological type of Str.pyogenes does not necessarily protect a patient againstinfection with another type.

(3) The so-called relapse in scarlet fever is due tofresh infection with a streptococcus picked up fromanother patient in the ward and differing in sero-logical type from that causing the primary infection.

(4) In multiple-bed wards for scarlet fever 50-70 percent. of the patients become reinfected with one ormore fresh types of Str. pyogenes during their periodof detention in hospital.

(5) Such reinfections may be latent or manifest.(6) Complications in scarlet fever occurring during

the third week and subsequently in multiple-bedwards are in the great majority of cases caused byreinfecting types of Str. pyogenes.

Turning to the paths of infection, Dr. Allisonquoted experimental proofs of spread by direct andindirect contact, illustrating the importance ofinfected toys, handkerchiefs, and eating utensils asvehicles of infection. Air-borne infection by dropletswas also a well-recognised means of spread, but thepart played by dry dust particles, in which Str.pyogenes could survive for a considerable time,was only beginning to be recognised. Exposure ofblood-agar plates for short periods in scarlet feverwards and examination of the resulting culturesindicated a surprisingly high degree of air infectionwith Str. pyogenes and the types isolated from theair were exactly those found as infecting agents inthe patients in the ward.

In measles wards and in the wards of generalhospitals the problem of the spread of streptococcal

841

infection was, said Dr. Allison, equally important.In a measles ward over a period of seven weeksStr. pyogenes had been isolated at some time duringtheir stay in hospital from 35 out of 43 patients and22 of these were the result of cross-infection occurringin the ward. Out of 17 cases of otitis media in theseries, 8 were due to cross-infection with types ofStr. pyogenes from other patients in the ward. The

problems raised by these findings were now beinginvestigated and cumulative evidence showed the

pressing need of dealing with them with a view togetting fewer complications, a decrease in the averageperiod of hospitalisation, and better end-results oftreatment.Dr. R. CRTJICKSHANK (L.C.C. Group Laboratory,

N.W. Hospital) said he wished to draw attention

specially to air-borne infection. By this he meantnot " droplet " or " spray " infection which had

only a very limited spread but the dissemination ofbacteria by the air rather like nature’s method of

sowing seeds. Recent epidemiological and bacterio-logical findings have suggested that infection-andnot only respiratory tract infection-spreads, in spiteof rigid precautions against manual transference, byfomites or by carriers. The work of W. F. andM. W. Wells in America has demonstrated how thismay be possible. They showed that droplets expelledinto the air by coughing and sneezing need not

immediately fall to the ground within a few feet ofthe individual. If the droplets do not exceed01 mm. in size, evaporation rapidly reduces them toso small a compass that they remain suspended inthe air like particles of smoke. Larger droplets orother infective material that do settle may becomeevaporated and be lifted into the air again as dust.The potentiality of these " droplet nuclei," as Wellscalls them, for spreading infection will depend amongother factors on their viability and their concentra-tion. Wells found that certain organisms whichcommonly occur in the upper respiratory tract,e.g., haemolytic streptococcus, pneumococcus, C. diph-therice, remain viable in the atmosphere for two days,whereas intestinal bacteria, e.g., B. coli, typhosus,and dysenterim, died off within eight hours.Dr. Cruickshank went on to give examples in his

own experience of air-borne spread of streptococcalinfection, corroborated by the new method of sero-logical typing.The first of these concerned infection of burns

which are particularly susceptible to the strepto-coccus. In a burns ward, it was found that 8 caseswere infected with the same type of Str. pyogenes,that the dust and atmosphere of the ward containednumerous haemolytic streptococci, and that a strainisolated from the dust was the same serological typeas a culture from an infected burn. Great care wastaken to prevent manual spread from case to case andthroat carriers among the nursing staff were notcommon.

The second example was a small outbreak of puer-peral sepsis where throat carriers and direct trans-ference could be almost certainly excluded and whereagain the epidemic type of Str. pyogenes was found inthe atmosphere of the ward. The abraded genitaltract of the parturient woman is, like a burn,particularly susceptible to attack by the streptococcus.Occurrence of streptococcal infections (tonsillitis,

otitis media, and vaginitis) in a diphtheria ward ofyoung children furnished the third example. Inaddition to the clinical infections most of the childrenhad hsemolytic streptococci in the nose or throat(more particularly in the nose), whereas there wereno carriers among the nursing staff. Usemolyticstreptococci of the two infecting types were present onplates exposed in the ward and were most numerous

where the infected cases were occurring (althoughthe plates were beyond the reach of " droplets ")and after the dust of the ward had been stirred upby sweeping and dusting.

Dr. Cruickshank suggested that we should not betoo ready to incriminate nursing staff for the spreadof infection, that we must not depend too much onbed-isolation to prevent spread, and that wet dustingshould be the routine practice in infected wards.

DISCUSSION

Dr. R. A. O’BRIEN (Wellcome Research Labora-tories) thought that some of the findings might beopen to criticism if they were based on the examina-tion of a single swab from the patient on admission.The opening papers raised some interesting questions.Was the Dick-negative nurse less likely to get astreptococcal infection in a heavily infected ward ’1Was it necessary to nurse every patient with a hsemo-lytic streptococcal infection in a single room openonly to the air 1 Should as much care and attentionbe given to streptococcal carriers as to typhoidcarriers ? ’1

Mr. T. B. LAYTON (otologist, L.C.C. Fever Hospitals)had visions of patients with heamolytic streptococcalinfections being nursed in wards appropriate to thetype of the organism. He commented on the tendencyto remove otitis cases from scarlet fever wards inorder that they might be isolated, and observed thatit was not the otitis case who required to be isolatedbut the pre-otitis cases. He felt strongly againstputting children with ear conditions in glass cells orcubicles as adverse psychological effects mightresult. The mind as well as the microbe had to bekept in view. He also discussed the role of thenurse in cross-infection.

Dr. F. GRUNDY (M.O.H., Luton) suggested thathowever desirable the practice of swabbing and

typing of streptococci might be from a scientific

point of view, he wondered if the information thusobtained might not be misinterpreted on occasionsin a court of law if an action were brought againsta local authority in consequence of cross-infection.Information obtained by swabbing might possiblyoperate prejudicially in a legal action. With regardto cubicle and chamber nursing it should not belost sight of that a policy which is practicable in thecase of large infectious hospitals, such as thoseof the L.C.C. and county boroughs, would be

impracticable in the majority of small isolationhospitals. Some attempt however should be madein these to reduce the incidence of so-called relapsesin scarlet fever by the avoidance of overcrowdingand by grouping cases in such a way that convalescentswithout complication are not brought into contactwith acute admissions.

Dr. A. TOPPING (sen. medical officer, L.C.C.) saidhe did not entirely agree with Mr. Layton aboutthe bad psychological effect of keeping children insolitary isolation where single rooms were constructedmainly of glass. In modern single-chamber unitschildren had little if any feeling of being shut off fromtheir fellows and the majority of them kept remark-ably cheerful. He emphasised the necessity for

agreement as to the name to be applied to suchseparation rooms ; the word " cubicle " should,he thought, only be used where walls did not extendfrom floor to ceiling. There was, he suggested, a

tendency to attribute the occurrence of puerperalsepsis to the nurse or the midwife in the case whohappened to harbour a hsemolytio streptococcus inthroat or nose without excluding other more likelycauses.

842

Dr. E. H. R. HARRIES (L.C.C. North Eastern

Hospital) endorsed the opinion of Dr. Topping thatin cubicles or chambers of modern design and lay-outchildren did not become depressed and miserable."

Singularly cheerful " had been applied byindependent medical observers to the demeanour ofchildren in the new chamber blocks at his own hospital.As to the role of particles floating in the air of wardsas agents in the dissemination of infection, as distinctfrom droplet spray, Dr. Harries drew attention toC. V. Chapin’s classical " Sources and Modes ofInfection " (1910). This book was in a way the bibleof those, such as Dr. Claude Rundle, who had carriedout the earliest experiments which led to the establish-ment of bed-isolation methods in this country.Chapin discounted the importance of air-borneinfection and stressed that of droplet spray, the handsof attendants, and utensils. Damp-sweeping, or

better the use of vacuum cleaners, was an essentialpart of the technique of bed-isolation. Nobody wouldintentionally admit patients in the early stage of

chicken-pox or measles to a bed-isolation ward.The infectious conditions most safely managed inthese wards without spread were those due to thehsemolytic streptococcus. Patients suffering fromscarlet fever, erysipelas, and puerperal sepsis had inhis own experience been nursed at the same time inthe same ward under bed-isolation conditions without

spread of infection to other patients. Nevertheless,other factors remaining unaltered, it was possible soto increase the load of streptococcal infections inthe ward that the system broke down and cross-infection occurred. Dudley’s conception of the" velocities of infection " was, he thought, important.Dr. J. C. SLEIGH (M.O.H. Chatham, late Chelmsford)

remarked that a curious feature of the Chelmsfordoutbreak was that of 33 cases of scarlet fever withonset in the fortnight previous to the milkman

infecting the milk 28 received their milk from theinfected source. They were late notifications andso were not typed but it suggested that the milkhad been infected earlier, that the milkman wasinfected from his own milk, and that the passagethrough the human host had raised the virulence ofthe strain, leading to the explosive outbreak. Withthe assistance of Dr. Camps typing had been continuedsince the outbreak and it was found that in a

comparatively small district there were seldom morethan 3-4 types at any one time. Cases showingsecondary rises of temperature were re-typed andalways showed a different type from that obtainedon admission. Lately all cases had been kept inbed till fit for discharge ; this had lowered consider-ably the amount of cross-infection and as they wereusually negative for hspmolytic streptococcus by theend of the third week it had not meant keeping themin bed too long. Typing also helped in separatingout true "Return" cases. A patient had beenadmitted as a probable mastoid ; he was type 6but cleared up and was discharged. Within 36 hourshe was readmitted almost moribund and died within24 hours of streptococcal meningitis. It looked aif a bad mistake had been made until the strepto.coccus in pus from the brain was shown to be oJ

type 1, and there were no other cases of that typ(in hospital at the time. Unless one could type th{streptococcus found it was, he thought, unwise tcswab the midwife’s throat, as it would simply tak(off duty a large number of midwives unnecessarily.

Dr. J. MCGARRITY (City Hospital, Birminghamadvocated the value of fresh air and bed-isolatioi

principles in ordinary wards. He deprecated overcrowding. In Birmingham there were three bed

isolation wards where all sorts of doubtful cases wereisolated ; in these wards cross-infection was non-

existent during recent years. The technique ofbed isolation was carefully observed and the windowswere wide open all the time, both night and day evenin the winter. The temperature of the ward did notmatter ; patients could be kept warm with the helpof extra blankets and hot-water bottles. Stuffyovercrowded wards in his experience were bad for thepatients and led to such troubles as tonsillitis andrhinitis.

Dr. E. C. BENN (City Hospital, Leeds), speakingof the immunity of Dick-negative reactors to strepto-coccal infections, said that a fall in the relapse-rateof scarlet fever to less than 1 per cent. followedartificial immunisation by scarlet fever toxin of thosechildren who remain Dick positive in the second weekof the disease. He mentioned the frequent occurrenceof streptococcal tonsillitis in fever nurses during thefirst few weeks of their hospital service. As theirimmunity to streptococcal infection increased, eithernaturally from exposure to infection or as a result ofartificial immunisation, the incidence of strepto-coccal tonsillitis fell sharply.

Dr. M. MITMAN (L.C.C. Rivers Hospitals) concededthe possibility of aerial contamination by suspendedinfectious particles, but thought that if it occurred,it was, in most instances, the result of droplet spray.Infection in the air or dust becomes diluted rapidlyas the result of drying, the action of sunlight, and themovement of air in a well-ventilated ward. In

consequence, the mass of infection is usuallyinsufficient to initiate an attack of the disease. Direct

droplet infection must still be considered the mostimportant mode of transmission of infectious diseases.In investigating the contamination of the atmospherewith suspended particles he suggested, as a possiblealternative to the elaborate air centrifuge, a blood-agar plate moving slowing in a vertical directionthrough the air. An adjacent stationary plate wouldprovide evidence of infection from falling particles.In this way a comparison between floating and fallingparticles could be obtained. Dick-negative subjectswere on the whole, he believed, more resistant tohaemolytic streptococcal infections than Dick-positiveones. In acquiring immunity to the antigens of thetoxin, a person must also have had an opportunityof acquiring some immunity to the antigens of theorganism itself, such as those responsible for itsinvasive properties. Although the Dick test wasno measure of this bacterial immunity, a negativeresult indicated a previous acquaintance with theorganism. Difference in the behaviour of the same

type of streptococcus gaining access to the bodythrough different portals of entry was attributable,he thought, to differences in local immunity.

FELLOWSHIP OF MEDICINE AND POST-GRADUATEMEDICAL ASSOCIATION. - The following post-graduatecourses have been arranged to take place duringMay : psychological medicine at the Maudsley Hospital(April 25th to May 28th) ; plastic surgery at varioushospitals (May llth and 12th) ; proctology at the GordonHospital (May 2nd to 6th) ; gynaecology at the Chelsea

. Hospital (May 23rd to June 3rd). Week-end courses, will be as follows : cancer at the Royal Cancer Hospital, (April 23rd and 24th) ; children’s diseases at the Infants, Hospital (April 30th and May 1st); chest diseases,

at the Brompton Hospital (May 7th and 8th); general)

surgery at the Princess Beatrice Hospital (May 14th’ and 15th) ; physical medicine at the St. John Clinicl and Institute of Physical Medicine (May 21st and 22nd).

Further information may be had from the secretary of the- fellowship at 1, Wimpole-street, London, W.I.