THE LOCALISATION OF SPIROCHBTES IN THE PAPULES OF YAWS.

By THEODORE SHENNAN, M.D., F.R.C.S.Ed., Senior Pathologist, Royal Infirmary, Edinburgh, ete.

Two years have elapsed since Castellani first described and figured spiroch&es in films made from Yaws papules. His observations were repeated and extended in later papers, and have been confirmed by other investigators. In his earlier communications Castellani was careful not to claim that his XpirocJmta pertenuis was the cause of Yaws, but his later papers (1907) show that he now considers that he has good grounds for making that claim. “ Yaws is to be considered a form of spirochzetosis or, better perhaps, treponemosis. The specific

agent of the disease is, according to all prob- ability, the SpirochcEta or, more correctly, the Trepo- nema pertenuis” (sic).

It is not necessary for me to refer to the methods of demonstration or the appearances presented by spirochztes in stainedfilms from Yawspapules. I wish, instead, to describe sections of i~ papule impregnated with silver, according to Levaditi’s original method (1. 1 9 0 B), which display the spirochEtes in position in the tissues.

These preparations (Fig. 1 ) were demonstrated a t the meeting of the Pathological Society of Great Rritain and Ireland on June 8, 1907.

For the papule I am indebted to Dr. A. Yale Massey, Kansanshi, N.W. Rhodesia, who had previously, in the summer of 1906, sent me films from Yaws in which spirochztes were readily demonstrable.

FIG. 1.

SPIROCHATES IN THE PAPULES OF YA WS. 427

Encouraged by the good results attained by Levaditi‘s methods in demonstrating spirochcetes in tissues from congenitally syphilitic children, 1 asked him if he could send me freshly excised Yaws papules, so that I might attempt to demonstrate the Spiyochwta pertenuis (in situ) by similar methods. I n the beginning of 19 0 7 I received from him a perineal papule of six months’ standing, carefully sealed up in 5 per cent. formdin solution. In spite of the long journey it arrived in per- fect preservation. Slices, 1 mm. in thickness, were treated according to Levaditi’s original method, and sections were cut after embedding in paraffin.

As will be seen on reference to the low-power photograph (Fig. 2) of the silvered section, the tissue removed consists principally of thickened epithe- lium. The con- nective tissue corium forms a thin layer (C), from which numerous nar- row, elongated papillary pro- cesses pass up into the epithel- ium, some of them almost reaching the surface. The corium stains of a brown colour, no granular de- posit being evi- dent even with high powers. Fro. 2. The epithelium presents several distinct appearances. The layers near the corium and its processes are approximately normal. The cells, the nuclei of which appear as pale spots, and their prickles, can be readily distinguished. They, like the corium, stain of a brown colour, and show an extremely fine granular deposit, which is not sufficient to obscure details of structure. In the photograph these are the darker, deeper portions of the epithelium E. Secondly, there are numerous pale patches S E, in which the epithelial cells are swollen, vacuolated, and degener- ating. The outlines of the individual cells are still apparent, and scattered over them is a scanty deposit of black granules. Thirdly, on the surface there is a granular, cellular layer, the more superficial parts of which are deeply impregnated with silver. And lastly, there

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428 THEODORE SHENNAN;

are some small sharply circumscribed areas A, seen best to the extreme left of the photograph, almost colourless, which if stained by ordinary methods, or counterstained in the silvered sections, contain leucocytes.

With few exceptions the spirochztes are t o be found in the epithelial layers, and particularly in the situations indicated on the photograph by the dotted circles. Five such areas have been marked out in this manner, and their position indicates that spirochztes occur most commonly either within, or a t the margins of, or in close proximity to, the pale degenerating portions of epithelium. Within many of these areas they are present in great numbers, and a t times form closely matted clumps.

In the deeper epithelium nearer the corium spirochztes are less frequently seen. Occasionally isolated individuals are found in the columnar layer of the rete Malpighii, lying apparently between the cells close to a process of the corium. They might possibly be mistaken for spiral filaments of fibrin, which, in some acute cutaneous inflammations, can be seen passing between the cells of the deepest layers of the rete Malpighii. These fibrin spirals are, however, numerous, and vary a little in thickness, and, moreover, I have not been able to demonstrate them by a silver method.

I n a few parts of the section, where the end of a papillary pro- cess touches one of the pale degenerated areas described above, numerous spirochztes may be seen in the extreme tip of the process.

It is exceptional to find spirochztes in the deeper parts of the processes, and I have never succeeded in finding any in the coriuni proper.

After locating the spirochztes in a silvered section the silver may be removed by one of the methods recommended by Dohi (1 9 O'l),-for example, by treating with a 1 0 per cent. solution of potassium ferro- cyanide, followed by 25 per cent. solution of hyposulphite of soda. The section may now be stained by any of the usual histological methods. I find that Leishman's method gives very beautiful results.

On microscopical examination of sections treated in this way, the areas E and S E are now found to merge into each other more gradually than is indicated in the silvered sections, while the superficial layer G is now seen to consist of a closely packed layer of leucocytes, principally polymorphonuclear, which also fill up cracks and hollows, passing down into the epithelium. The small rounded sharply circum- scribed areas A are pockets in the epithelium filled up with similar leucocytes. Polymorphonuclear leucocytes also penetrate the widened spaces between the prickle cells in the more healthy portions of the epithelium. The corium and its processes are extremely cellular, the cell most frequently met being the plasma cell of Unna and Marschalko.

It is evident that these spirochEtes have invaded the skin froni the surface. The largest collections are to be found in areas near the surface. In these collections numerous fragmented, apparently de-

SPIROCHATES IN THE PAPULES O F YAWS 429

generating, spirals are to be seen, which may be considered older forms. Spirals found in the deeper layers of the epithelium are invariably well formed, are evidently younger than the others, and are attempt- ing to make their way towards the corium. Only occasional spirals were found in the processes of the corium, and none in the coriurn proper.

The appearances thus differ from those presented in syphilis, in which the spirochcetes are found constantly in the corium, and passing upwards into the deeper layers of the epithelium.

Since preparing this paper for publication I find that Schiiffner (9. '7. 190'7), of Deli, Sumatra, has also succeeded in demonstrating spirochates in. situ in Yaws by a silver method, that of Bertarelli and Volpino. His description corresponds with that I have given above, except that he finds spirochztes most abundantly in the rounded pockets containing polymorphonuclear lencocytes. Such is not my experience in this case. I have only found occasional, isolated spirochcetes in these situations.

REFERENCES.

(I do not attempt to give references to all the literature on the subject of Yaws. CASTELLANI . . . . . Brit. Med. Journ., London, 1907, ii. p. 1512. DOHI . . . . . . . Centralbl. f. Bakteriol. u. Parasitenk., Jena,

1907, Abth. 1, Orig. Bd. xliv. Heft 3, S. 246. LEVADITI . . . . . . .Ann. de Z'lnst. Pasteur, Paris, 1906, tome xx.

p. 41. SCHUFFNER . . . . Munchen. naed. Wchnschr., July 9, 1907, S. 1364.

I only refer to the papers I have quoted.)