ORIGINAL C O M M U N I C A T I O N S

A SHORT ACCOUNT OF DYSENTERY IN

DUI3I~]N 1N T H E AUTUMN OF 1919.

BY A D R I A N S T O K E S ANI) J. W. B I G G E R .

[Read in the Section of Pathology, 9th January, 1920.]

TOWARDS the end of August, 1919, we became aware that there was a considerable amount of severe diarrhoea, with some fatal cases, in the district which lay between Sir Patrick's Dun's Hospital and the River Liffey. This epidenfie seemed worth investigating, and we arranged to procure specimens of the dejeeta from some typical cases which were at that time being adnfitted to Sir Patrick Dun's Hospital. We were able to prove that the B. dyse~tcri~ of Shiga was present in nine of the first eleven specimens examined. The Public Hea!th Authorities then took the matter in hand, and it was arranged that specimens should be sent for examination from all the suspicious cases. I t was further arranged that cases should be admitted to Sir Patrick Dun's Hos- pital and Cork Street Fever Hospital. Specific anti- dysentery serum was provided by the city authorities for the treatment of the cases.

Tcch~iq~e o/ 18olation and Identificatiom--Speeimens were sent to the laboratory in the ordinary tubes provided for the purpose. We insiste-t that all specimens should be sent to the laboratory at the earliest possible moment after their collection, and that care should be exercised in selecting suitable material--blood-stained mucus, pus and mucus being the mo.~t favourable specimens for ex- amination. On arrival, particles of blood-stained mucus

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were carefully washeu in two successive tubes of sterile salt solution, and a small fragment was spread on the medium in use. The first hundred specimens were plated in duplicate on MacConkey's and Endo's media. As there was no difference in the nmnber of isolations of the pathogenic organism, the former was selected for use during the rest of the epidemic. The plates were incubated for 18 to 20 hours, and were then examined, suspicious colonies being picked off into undiluted Shiga ~md Flexner agglutinating serum. This rough agglutina- tion was used as a preliminary indication of which colonies should 1)e chosen for further investigation. Colonies giving an agglutination in 15 seconds were subcultured into lactose peptone water and incubated for 10 to 24 hours. The culture so obtained was used for agglutina- tion at the full titre of the serum (1-1000) and for dis- tribution into tubes of glucose, mannite, saceharose, maltose, peptone water, and agar. In the majority ('f organisms isolated macroscopic agglutination was again done, the agar slope serving to furnish the emulsion.

The ag'glutination and sugar reactions being positive and the indol reaction being negative, the organism was regarded as a B. Shiga, and reported as such at the end of 48 hours.

Specimens sent for Exa~Mat ion : -

Patients No. of B. Sh iga Number of examined specimens isolated cases proved

168 354 101 76

Of the 168 individuals examined, there are 29 who can be excluded for some good reason as not having suffered from dysentery. This gives 76 eases proved out of 1..'39, which is 54.6 per cent. This figure does not represent the true picture, as a considerable number of the specimens sent were not examined during the active :stage of the disease, but were tested, prior to the dis- charge of the patient, when he was definitely convales- cent.

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Analysis of 77 specimens, showing the results accord- ing to the nature of the specimen sent : -

Description N u m b e r P e r c e n t a g e p o s i t i v e

B l o o d a n d m u c u s ... 30 ... 100 M u c u s . . . . . . 10 ... 40 S w a b . . . . . . 13 ... 30 Fa~ces . . . . . . 24 ... 16

The results obtained from the examination of blood and nmcus are extraordinarily high, and we will comment on this later in the paper.

Analysis of the results of examination of 149 specimens from 60 patients in Sir Patrick Dun's Hospital : - -

1st w e e k 2 n d w e e k 3 r d w e e k 4 t h w e e k

h I u m b e r o f s p e c i m e n s ... 72 41 18 18 P e r c e n t a g e p o s i t i v e ... 5 7 % 2 4 % 17~ 1 7 %

Twenty-nine cases from whom B. Shiga had been in ~heir sere. and 8 normal sere were taken for controls. The a.gglutinations were done macroscopically, a.nd incu- bated for 18 holtrs at 37 ~ C. The emulsion was made in carbol saline from five strains which were isolated during the course of the epidemic.' The suspension was stan- dardised to contain 2,500 million bacilli to the c.c. We give here a short extract showing some characteristic examples of the reactions obtained in this epidemic.

D a y s I l l . - - S e r u m d i l u t e d . 1 - 1 0 1 - 2 0 1 - 3 0 1 - 4 0 1 - 6 0 1 - 8 0 1 - 1 2 0

2 . . . . . . C C C T - - 5 . . . . . . C C C C C T - 8 . . . . . . C T . . . . - -

18 . . . . . . C C C C C C - 21 . . . . . . C C C C C C T 22 . . . . . . C T . . . . . .

C o n t r o l s .

1 . . . . . . C T 2 . . . . . . T 3 . . . . . . T - 4 . . . . . . T 5 . . . . . . T -

7 . . . . . . - - - -

8 . . . . . . -

C r e p r e s e n t s c o m p l e t e a g g l u t i n a t i o n . T r e p r e s e n t s a t r ace .

The agglutination in dysentery cases is notoriously irregular, and the above Table amply demonstrates this.

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Morbid Anatomy.--We were only in a position to per- form autopsies in three cases, in two of which the typical lesions of acute bacillary dysentery were found. The entire colon and the lower part of the ileum were in a state of acute inflanmmtion; tile colon showed thicken- ing of the wall, a false membrane on the surface, and numerous ulcerated patches. Catarrhal inflammation of the glands, fibrinous cedema and cell infiltration of the submucons coat, with intense congestion of the vessels, and, in places, necrosis and sloughing of the mucous coat were seen in microscopic sections.

The third case in which an autopsy was performed was that of an elderly patient, who died as a result of a strep- tococcus septicamia when convalescent from dysentery. The colon in this case showed unmistakeable signs of dysentery, but the ulcerative process had progressed to the stage of repair, the thickening of the intestine had disappeared, and there were signs of the regeneration of the mucus membrane; t.he macroscopic findings were confirmed microscopically.

Epidemioloqy.--The following Table shows the noti- fications and deaths during the epidemic : - -

M o a t h s N o t i f i e d D i e d

S e p t e m b e r . . . 1 1 4 12

O c t o b e r . . . 5 6 3

N o v e m b e r . . . 14 3 D e c e m b e r . . . 2 1

T o t a l . . . 1 8 6 19

It should be noted that 173 of the notification cases were from the city and 13 from the Pembroke Urban District. Of the city cases, 141 came from one dispen- sary district, No. 4 South; the number af cases notified from the north side of the river was very small. Although the notification of dysentery cases only commenced in the first week of September, there is good reason to believe that there were a small number of cases in August and probably a few in July.

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Notifications and deaths by ages :--

A g e N o t i f i e d D i e d

0 - 5 . . . 2 3 2

5 - 1 5 . . . 4 9 2

1 5 - 2 5 . . . 3 8 1

2 5 3 5 . . . 2 5 0

3 5 - 4 5 . . . 2 1 1

4 5 - 5 5 . . . 15 6

5 5 u p w a r d s . . . 15 7

The death-rate for all the (.ases notified was approxi- lnately 10 per cent. ; at ages up to 45 years it was 3.8 per ~'ent. ; and f rom 45 upwards was 43.3 per cent.

As soon as the epidemic became known Dr. M. a. ]{ussell, Assistant Medical Oflieer of Hea l th , investigated the food and milk supply of the houses in which eases ~f dysentery had occurred, but was unable to find any common source from which the epidemic might have arisen.

The area from which most of tile dysentery cases came is one in which the sani tary conditions leave nmch to he des i red: t e ne men t houses, overcrowding, and flies give ample scope for the spread of an epidemic.

t l c m a r k s . - - F r o m the historical point of view, we think tha t tile epidemie is of some interest , as, so far as we have been able to ascertain, there has been no outbreak of dysentery in Dublin in modern times. The re have been three small epidemics reported in Eng land during the last few years, but in none of them were the cases so nmnerous as in Dublin. The fact tha t there were not mauy cases till the end of August had, we believe, a definite result in l imiting the epidemic. The weather conditions in August Were eminent ly favourabte for the spread of the disease, whereas the cold and wet weather which prewuled during September was inimical.

I t is worth not ing that only one ease of dysentery was. proved to be caused by an organism of the F lexner group.

Another point on whieh we wish to comment was the comparat ive ease with whieh the organism >'as isotated. W e have had eonsiderable experience of dysentery epi-

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demics, and were surprised at the facility with which we obtained cultures of tile Shiga bacillus. From the sped- mens of blood-stained mucus sent for examination it was the rule to obtain pure, or almost pure, cultures, and the number of times we isolated the organism from such specimens was very high. We rarely obtaine'.l a specimen which was less than 4 hours old, but in spite ,)f this we had little difficulty in isolating the organisms in fairly early eases.

\Ve have an impression that the organism was not of a very virulent variety. Our reasons are-- that of three strains that were inoculated alive into rabbits in con- siderable doses (2,000, '2,500, 5,000 millions) none pro- duced any serious reaction. Further, the death-rate in the epidemic was, on the whole, low. As a final proof of the identity of the organism, the serum of a rabbi~ inmmnised with the Dublin strain was shown to agglu- tinate four strains (Lister Institute, R.A.M. College, Standards Lab. Oxford and ~Laboratory Strain) to the full titre of the serum.

~re further wish to remark on the titre of agglutina- lion obtained with the sera of patients. We believe thaV t.he strains which were used for preparing the suspensions were of relatively low agglutinability--possibly because they had on]y recently been isolated. In support of this we add a short Table.

Comparison of titre obtained in the agglutination of three sera with homoloR'ous strain and Oxford Standar(I strain. Emulsions of the same strength were used : - -

Serum number Agglutination end point. Homologous strain Oxford strain

17 ... 1-80 1-240 1 8 . . . 1 - 4 0 1 - 8 0 21 ... 1-30 1-60

We wish to acknowledge our indebtedness to many practitioners, and especia',ly to Dr. 1VI. J Russell and to r Resident and Consulting Staffs of Sir Patrick Dun's Hospital and Cork Street Fever Hospital.