THE INFECTING AGENT OF EXANTHEMATIC TYPHUS.
1
78 Annotations. THE CENTENARY OF THE LANCET. "Ne quid nimis." THE dinner in celebration of the completion of the hundredth year of THE LANCET will be held in London on Wednesday, Nov. 28th, 1923. Sir Donald MacAlister, President of the General Medical Council, will take the chair, supported by the President of the Royal Society, the President of the Royal College of Physicians of London, the President of the Royal College of Surgeons of England, the Chief Medical Officer of the Ministry of Health, the President of the Royal Society of Medicine, and the President of the Medical Society of London. Dr. J. H. W. Laing and Mr. H. D. Gillies (7, Portland-place, London, W.) are acting as Honorary Secretaries to the Dinner Committee. ____ THE INFECTING AGENT OF EXANTHEMATIC TYPHUS. Prof. W. Barykin and Dr. N. Kritsch, of Moscow, have announced the discovery of what they claim to be "with very great probability" the cause of exanthematic typhus. Prof. Barykin has for four years been investigating typhus. He early found that the typhus process so altered the blood-vessels as to facilitate infection of the blood-stream with myriad micro-organisms, all of whom the blood of typhus cases agglutinated. It was in consequence of these very various infections that complications were so frequent, occurring as they do in 30 or even 60 per cent. of the cases. Secondary infections being so frequent, he concluded the true cause could only be discovered in the body in the early days of the disease, in the pre-eruptive stage, and that he could hope for no help from agglutination ’reactions. So he investigated 23 cases of pre-eruption typhus, finding nothing then in the blood but some small elements (0’4-1-5), closely resembling Rickettsia prowazeki (064.) or young forms of Plotz’s bacillus (0.9-1.9,u); to these he gave the name Microbion typhi exanthematici. He and Afanassieff proceeded then to seek for it in 150 cases of human typhus, in 200 typhus-inoculated guinea-pigs, and in specimens from 11 early post-mortem examina- tions. They found that in the early days of the stage of invasion the bacterium (there seems no occasion for the term microbion) is so constantly present in the blood of the guinea-pig that, by its presence or ,, absence, diagnosis can be definitely made even in the pre-eruptive stage, but the search may last for hours, and many films may have to be examined. It was in the blood that the bacterium was first found, but it occurs in far greater numbers in the cells of the brain, the spleen, and the suprarenals, growing within the cells into clusters, and in time killing the cells. The bacterium is not discoverable during the stage of incubation, and it could not be found in the organs of a hundred uninfected guinea-pigs and men. The investigation next concerned itself with lice ; the bacterium was found in the intestinal epithelium and intestinal contents of 1050 of 1500 infected lice ; it could not be found in lice from uninfected men. Further, in the intestinal contents of 280 infected lice, the bacterium was found in 192 ; it was found in the epithelium in 14 of the infected, in only one of the controls. It was difficult to make cultures of the bacterium until Kritsch hit upon the idea of making a medium out of the tissues in which the ., microbion" is, customarily, most plentifully found. A pancreatised ,sterile broth being prepared, small portions of brain or spleen were rapidly removed under aseptic precautions, at early post-mortems of men or guinea-pigs dead in the first stage of the disease ; these portions were minced very finely, mixed with the broth, and tubed. The tubes were over-layered with paraffin and incubated 1 Archiv flit Schiffs- und Tropen-Hygiene, 1923, Nr. 2. at 37° C. During the first ten days, the bacteria whicn had at first appeared, had gradually died out, and then the " microbion " might appear ; it begins to grow in the tissue cells, only later spreading to the fluid. It begins as clusters of Gram-negative cocci, very small; later they increase in size and begin to stain with Gram. It is non-motile. At 37° C. they remain alive for 4-6 weeks, but die in an hour at 50° C. ; ; once established it can be grown on pancreatised spleen- or brain-broth agar, on which it grows, aerobically, in round, glistening colonies. The growth is difficult to emulsify in normal saline ; it will not grow in broth. Lastly, of 22 guinea-pigs inoculated with these cultures, 14 became infected; their disease, clinically, closely resembled typhus ; few of them died, but in the ten that were killed at the close of the pyrexial stage there were found—hyperasmia of the spleen follicles with hyperplasia, hyperaemia of the supra- renals, hyperaemia and oedema of the brain ; in other words, the histo-pathology of the infection produced by the bacterium in the guinea-pig is identical with that originated by typhus in man. On the strength of these observations Prof. Barykin and Dr. Kritsch make the claim that the bacterium is " very probably " the cause of typhus fever. We call attention to their interesting and suggestive observations. In spite of all the work which has been done upon it, the Rickettsia is not yet firmly habilitated as the cause of typhus. That the blood in typhus patients is invaded by other organisms needs confirmation. But the Russian authors have found a ready means of cultivating the infecting agent which will pave the way for further investigation. ____ ACID-FASTNESS. , ALTHOUGH acid-fastness has always been associated : with the fatty constituents of the bacillus, this property , cannot be removed from the organism by extraction with fat solvents alone. This fact may be considered well established, as Dr. J. A. Shaw-Mackenzie reminds us in his letter in another part of this issue. Aronson 1 it was who showed that if the organisms are treated with an acid in addition to fat solvents the acid- fastness can be completely removed by prolonged extraction. This important piece of work was confirmed by many workers, including Bulloch and Macleod, Much and Deycke,3 3 and others. The latter observers also showed that any organic acid such as lactic would answer the purpose. Prof. Dreyer finds that he can remove the acid-fastness by the action of formalin and fat solvent extraction. No explanation is advanced for the action of formalin in place of the usual acid treatment, but it seems probable that it may act by virtue of the appreciable amount of formic acid always present in 40 per cent. formalin. If this is the case the action would be analogous to the reaction of Much and Deycke with lactic acid. The bacilli obtained by this combined formalin and fat extraction treatment are made into an antigen apparently possessing valuable therapeutic properties. Since the discovery and preparation of tuberculin by Koch a large amount of literature has collected on the methods of preparation of tubercular antigens. By varying the technique each worker has hoped to produce an antigen more sensitive for both diagnostic and therapeutic purposes. Gabrilowitsch 4 was probably the first to work on fractional antigens. In 1891 he described a " tuberculum purum," obtained by extracting bacilli with xylol, ether, chloroform, and alcohol. This preparation was used for therapeutic purposes. Armand-Delille,s in 1902, worked with ether- and chloroform-extracted bacilli, whilst Leber and Steinharter, in 1908, used an antigen prepared’ from chloroform-extracted bacilli on 350 patients. 1 Aronson: Berlin. klin. Woch., 1898, xxxv., 484; also 1910, xlvii., 1617. 2 Bulloch and Macleod : Jour. Hyg., 1904, iv., 1. 3 Much: Beitr. klin. Tuberk., 1911, xx., 345; also 1911, xx., 353. 4 Gabrilowitsch : Wien. med. Woch., 1891, No. 4. 5 Armand-Delille: Arch. Exp. Path., 1902. 6 Leber and Steinharter : Munch, med. Woch., 1908, No. 25.
Transcript of THE INFECTING AGENT OF EXANTHEMATIC TYPHUS.
78
Annotations.
THE CENTENARY OF THE LANCET.
"Ne quid nimis."
THE dinner in celebration of the completion of thehundredth year of THE LANCET will be held in Londonon Wednesday, Nov. 28th, 1923. Sir DonaldMacAlister, President of the General Medical Council,will take the chair, supported by the President ofthe Royal Society, the President of the Royal Collegeof Physicians of London, the President of the RoyalCollege of Surgeons of England, the Chief MedicalOfficer of the Ministry of Health, the President of theRoyal Society of Medicine, and the President of theMedical Society of London. Dr. J. H. W. Laing andMr. H. D. Gillies (7, Portland-place, London, W.) areacting as Honorary Secretaries to the DinnerCommittee.
____
THE INFECTING AGENT OF EXANTHEMATIC
TYPHUS.
Prof. W. Barykin and Dr. N. Kritsch, of Moscow,have announced the discovery of what they claim tobe "with very great probability" the cause ofexanthematic typhus. Prof. Barykin has for fouryears been investigating typhus. He early foundthat the typhus process so altered the blood-vesselsas to facilitate infection of the blood-stream withmyriad micro-organisms, all of whom the blood oftyphus cases agglutinated. It was in consequence ofthese very various infections that complications wereso frequent, occurring as they do in 30 or even 60 percent. of the cases. Secondary infections being so
frequent, he concluded the true cause could only bediscovered in the body in the early days of the disease,in the pre-eruptive stage, and that he could hope for nohelp from agglutination ’reactions. So he investigated23 cases of pre-eruption typhus, finding nothing then inthe blood but some small elements (0’4-1-5), closelyresembling Rickettsia prowazeki (064.) or young formsof Plotz’s bacillus (0.9-1.9,u); to these he gave thename Microbion typhi exanthematici. He andAfanassieff proceeded then to seek for it in 150 cases ofhuman typhus, in 200 typhus-inoculated guinea-pigs,and in specimens from 11 early post-mortem examina-tions. They found that in the early days of the stageof invasion the bacterium (there seems no occasion forthe term microbion) is so constantly present in theblood of the guinea-pig that, by its presence or
,,
absence, diagnosis can be definitely made even in thepre-eruptive stage, but the search may last for hours,and many films may have to be examined. It was inthe blood that the bacterium was first found, but itoccurs in far greater numbers in the cells of the brain,the spleen, and the suprarenals, growing within thecells into clusters, and in time killing the cells. Thebacterium is not discoverable during the stage ofincubation, and it could not be found in the organs ofa hundred uninfected guinea-pigs and men. Theinvestigation next concerned itself with lice ; thebacterium was found in the intestinal epithelium andintestinal contents of 1050 of 1500 infected lice ; itcould not be found in lice from uninfected men.Further, in the intestinal contents of 280 infected lice,the bacterium was found in 192 ; it was found in theepithelium in 14 of the infected, in only one of thecontrols. It was difficult to make cultures of thebacterium until Kritsch hit upon the idea of making amedium out of the tissues in which the ., microbion"is, customarily, most plentifully found. A pancreatised,sterile broth being prepared, small portions of brain orspleen were rapidly removed under aseptic precautions,at early post-mortems of men or guinea-pigs dead in thefirst stage of the disease ; these portions were mincedvery finely, mixed with the broth, and tubed. Thetubes were over-layered with paraffin and incubated
1 Archiv flit Schiffs- und Tropen-Hygiene, 1923, Nr. 2.
at 37° C. During the first ten days, the bacteria whicnhad at first appeared, had gradually died out, and thenthe " microbion " might appear ; it begins to grow inthe tissue cells, only later spreading to the fluid. Itbegins as clusters of Gram-negative cocci, very small;later they increase in size and begin to stain withGram. It is non-motile. At 37° C. they remain alivefor 4-6 weeks, but die in an hour at 50° C. ; ; once
established it can be grown on pancreatised spleen-or brain-broth agar, on which it grows, aerobically, inround, glistening colonies. The growth is difficult toemulsify in normal saline ; it will not grow in broth.Lastly, of 22 guinea-pigs inoculated with thesecultures, 14 became infected; their disease, clinically,closely resembled typhus ; few of them died, but inthe ten that were killed at the close of the pyrexialstage there were found—hyperasmia of the spleenfollicles with hyperplasia, hyperaemia of the supra-renals, hyperaemia and oedema of the brain ; in otherwords, the histo-pathology of the infection producedby the bacterium in the guinea-pig is identical withthat originated by typhus in man. On the strengthof these observations Prof. Barykin and Dr. Kritschmake the claim that the bacterium is " very probably "the cause of typhus fever. We call attention to theirinteresting and suggestive observations. In spite ofall the work which has been done upon it, the Rickettsiais not yet firmly habilitated as the cause of typhus.That the blood in typhus patients is invaded by otherorganisms needs confirmation. But the Russianauthors have found a ready means of cultivating theinfecting agent which will pave the way for furtherinvestigation.
____
ACID-FASTNESS.
, ALTHOUGH acid-fastness has always been associated: with the fatty constituents of the bacillus, this property, cannot be removed from the organism by extraction
with fat solvents alone. This fact may be consideredwell established, as Dr. J. A. Shaw-Mackenzie remindsus in his letter in another part of this issue. Aronson 1it was who showed that if the organisms are treatedwith an acid in addition to fat solvents the acid-fastness can be completely removed by prolongedextraction. This important piece of work was
confirmed by many workers, including Bulloch andMacleod, Much and Deycke,3 3 and others. Thelatter observers also showed that any organic acidsuch as lactic would answer the purpose. Prof.Dreyer finds that he can remove the acid-fastness bythe action of formalin and fat solvent extraction. Noexplanation is advanced for the action of formalin inplace of the usual acid treatment, but it seems
probable that it may act by virtue of the appreciableamount of formic acid always present in 40 per cent.formalin. If this is the case the action would beanalogous to the reaction of Much and Deycke withlactic acid. The bacilli obtained by this combinedformalin and fat extraction treatment are made intoan antigen apparently possessing valuable therapeuticproperties. Since the discovery and preparation oftuberculin by Koch a large amount of literature hascollected on the methods of preparation of tubercularantigens. By varying the technique each worker hashoped to produce an antigen more sensitive for bothdiagnostic and therapeutic purposes. Gabrilowitsch 4
was probably the first to work on fractional antigens.In 1891 he described a " tuberculum purum," obtainedby extracting bacilli with xylol, ether, chloroform, andalcohol. This preparation was used for therapeuticpurposes. Armand-Delille,s in 1902, worked withether- and chloroform-extracted bacilli, whilst Leberand Steinharter, in 1908, used an antigen prepared’from chloroform-extracted bacilli on 350 patients.
1 Aronson: Berlin. klin. Woch., 1898, xxxv., 484; also 1910,xlvii., 1617.
2 Bulloch and Macleod : Jour. Hyg., 1904, iv., 1.3 Much: Beitr. klin. Tuberk., 1911, xx., 345; also 1911,
xx., 353.4 Gabrilowitsch : Wien. med. Woch., 1891, No. 4.
5 Armand-Delille: Arch. Exp. Path., 1902.6 Leber and Steinharter : Munch, med. Woch., 1908, No. 25.
