BAMBOO HOUSE SUPPORTS SEALED WITH CEMENT TO PREVENT ENTRANCE OF RATS (MANILA PLAGUE CAMPAIGN)
BAMBOO HOUSE SUPPORTS SEALED WITH CEMENT TO PREVENT ENTRANCE OF RATS (MANILA PLAGUE CAMPAIGN)
Similar conditions were found in adjoining houses and in one case a live rat was driven out of a nest in the bamboo.
Sample of Detailed Orders Issued.—Sample of detailed orders issued by Medical Inspector in Charge of Plague Suppression. Similar orders were issued whenever new districts were entered or new work undertaken.
Memorandum Order. Effective March 25, 1913:Beginning to-day, 13 men under Assistant Inspector Parás, will commence cleaning operations at C. Ostra,extending from the Bay to C. Sande and will clean towards C. Moriones. They will be provided with a disinfecting pump and will disinfect the ground surfaces wherever disturbed, outdoors and indoors. Cleaning is to be done in the most thorough manner possible, searching meanwhile for rat nests and rat harbors; re-piling wood, tiles, stones and merchandise; moving all movable goods out of doors in their search for rats and rat-holes or nests. All goods are to be piled above ground at an elevation of at least one foot. All bamboo beds and bamboo rafters and parts of the house (in the basements) made of bamboo or of double walls are to be thoroughly investigated for rats. All foodstuff attractive for rats is to be placed in covered boxes or galvanized iron cans, tin cans or barrels, with tight-fitting covers. Special attention is to be paid to straw, hay, shavings, grain, rat-holes, and food.Two men will be detailed to cement up ends of bamboo and rat-holes, but will not do general repairing. They will carry materials for mixing cement as needed and will not be wasteful of materials.If this force proves to be insufficient in numbers, additional men may be detailed from the other working parties.[Signed]T. W. Jackson,Medical Inspector in Charge of Plague Suppression.
Memorandum Order. Effective March 25, 1913:
Beginning to-day, 13 men under Assistant Inspector Parás, will commence cleaning operations at C. Ostra,extending from the Bay to C. Sande and will clean towards C. Moriones. They will be provided with a disinfecting pump and will disinfect the ground surfaces wherever disturbed, outdoors and indoors. Cleaning is to be done in the most thorough manner possible, searching meanwhile for rat nests and rat harbors; re-piling wood, tiles, stones and merchandise; moving all movable goods out of doors in their search for rats and rat-holes or nests. All goods are to be piled above ground at an elevation of at least one foot. All bamboo beds and bamboo rafters and parts of the house (in the basements) made of bamboo or of double walls are to be thoroughly investigated for rats. All foodstuff attractive for rats is to be placed in covered boxes or galvanized iron cans, tin cans or barrels, with tight-fitting covers. Special attention is to be paid to straw, hay, shavings, grain, rat-holes, and food.
Two men will be detailed to cement up ends of bamboo and rat-holes, but will not do general repairing. They will carry materials for mixing cement as needed and will not be wasteful of materials.
If this force proves to be insufficient in numbers, additional men may be detailed from the other working parties.
[Signed]T. W. Jackson,
Medical Inspector in Charge of Plague Suppression.
Specimen order issued to Sanitary Inspector assisting in Plague Suppression by Medical Inspector in charge.
Sanitary Inspector, Bureau of Health:Please place the gang of workmen under your charge in the square bounded by Calles Velasquez, Moriones,Concha and Manila Bay which is infected with rat plague. Treat the houses and properties there in the same manner in which other plague-infected districts have been treated, viz.: by policing the houses and yards, vacating all basements of light-material houses in which human habitations are illegally present; removing (with the consent of the occupants) all unauthorized basement sleeping places, beds, platforms, etc., and other illegal structures, closing up the open ends of bamboo rafters or timbers of the house with tin or cement.Where the occupants resist this action sanitary orders should be issued in the usual manner and interference should be stopped until the order is served and complied with. There are a number of most insanitary and unsuitable shelters of bamboo, tin, etc., used for houses by a number of families in this square and it is desirable to tear down these huts if permission can be secured. If permission is refused orders should be issued on the usual form.[Signed]T. W. Jackson,In Charge of Plague Suppression.
Sanitary Inspector, Bureau of Health:
Please place the gang of workmen under your charge in the square bounded by Calles Velasquez, Moriones,Concha and Manila Bay which is infected with rat plague. Treat the houses and properties there in the same manner in which other plague-infected districts have been treated, viz.: by policing the houses and yards, vacating all basements of light-material houses in which human habitations are illegally present; removing (with the consent of the occupants) all unauthorized basement sleeping places, beds, platforms, etc., and other illegal structures, closing up the open ends of bamboo rafters or timbers of the house with tin or cement.
Where the occupants resist this action sanitary orders should be issued in the usual manner and interference should be stopped until the order is served and complied with. There are a number of most insanitary and unsuitable shelters of bamboo, tin, etc., used for houses by a number of families in this square and it is desirable to tear down these huts if permission can be secured. If permission is refused orders should be issued on the usual form.
[Signed]T. W. Jackson,
In Charge of Plague Suppression.
VIEW OF HOUSE AT 447 CALLE CONSERVADOR, TONDO, WHERE INFECTED RATS WERE FOUND (MANILA PLAGUE CAMPAIGN)
VIEW OF HOUSE AT 447 CALLE CONSERVADOR, TONDO, WHERE INFECTED RATS WERE FOUND (MANILA PLAGUE CAMPAIGN)
Specimen order issued by the Medical Inspector in charge of Plague Suppression.
Station "C," Tondo, May 21, 1913.Redistribution of rat catchers and laborers engaged in antiplague work. Effective May 2, 1913.Sanitary Inspector Kennard and 20 rat catchers will move into Tondo District and trap and poison rats in the district bounded on the west by Manila Bay and on the east by Estero Reina. The work will be begun at the extreme north water boundary of this district and will proceed toward the south.Sanitary Inspector Brantigan with a similar number of rat catchers (20) will work within the same east and west boundaries and will begin trapping and poisoning at Calle Moriones, proceeding north. The poisoning and trapping is to be done in the most thorough manner possible, as this is a dangerously infected district and rat-plague must be controlled and terminated here.The laborers, 60 men, divided into 4 parties of 15 men each under Assistant Sanitary Inspectors Jesús, De la Rosa, Laxamana and Parás, will continue the cleaning operations now under way on both sides of C. Juan Luna south of C. Moriones (plague localities in the same neighborhood), and thoroughly disinfect.One party of 15 men will work in the vicinity of C. Perla, vacate basements as habitations, search for dead rats in yards, houses, bamboos, under broken concrete, etc., and will close up openings in structural bamboo by means of tin and cement. Emphasis is placed upon the necessity for permanently vacating basements and men will be sent back over the ground daily to see that the persons moved out do not return. Reports are desired so that prosecutions for violations of the law may be instituted if necessary.[Signed]T. W. Jackson,Medical Inspector in Charge of Plague Suppression.
Station "C," Tondo, May 21, 1913.
Redistribution of rat catchers and laborers engaged in antiplague work. Effective May 2, 1913.
Sanitary Inspector Kennard and 20 rat catchers will move into Tondo District and trap and poison rats in the district bounded on the west by Manila Bay and on the east by Estero Reina. The work will be begun at the extreme north water boundary of this district and will proceed toward the south.
Sanitary Inspector Brantigan with a similar number of rat catchers (20) will work within the same east and west boundaries and will begin trapping and poisoning at Calle Moriones, proceeding north. The poisoning and trapping is to be done in the most thorough manner possible, as this is a dangerously infected district and rat-plague must be controlled and terminated here.
The laborers, 60 men, divided into 4 parties of 15 men each under Assistant Sanitary Inspectors Jesús, De la Rosa, Laxamana and Parás, will continue the cleaning operations now under way on both sides of C. Juan Luna south of C. Moriones (plague localities in the same neighborhood), and thoroughly disinfect.
One party of 15 men will work in the vicinity of C. Perla, vacate basements as habitations, search for dead rats in yards, houses, bamboos, under broken concrete, etc., and will close up openings in structural bamboo by means of tin and cement. Emphasis is placed upon the necessity for permanently vacating basements and men will be sent back over the ground daily to see that the persons moved out do not return. Reports are desired so that prosecutions for violations of the law may be instituted if necessary.
[Signed]T. W. Jackson,
Medical Inspector in Charge of Plague Suppression.
Specimen order issued to Assistants.
May 4, 1913.Station "C," Bureau of Health:Please place work parties in (interior) 1627–1629 Sande and 525 C. Azcarraga, to clean, disinfect and thoroughly investigate these premises and the houses, stables and other buildings in the vicinity. Search for rats, livingand dead, rat nests and rats in bamboos and wood piles, stone piles, stables, under planks and elsewhere. Cement the openings in bamboos in houses or close with tin. Make notes on needed structural work. Do the work as thoroughly as possible.[Signed]T. W. Jackson,Medical Inspector in Charge of Plague Suppression.
May 4, 1913.Station "C," Bureau of Health:
Please place work parties in (interior) 1627–1629 Sande and 525 C. Azcarraga, to clean, disinfect and thoroughly investigate these premises and the houses, stables and other buildings in the vicinity. Search for rats, livingand dead, rat nests and rats in bamboos and wood piles, stone piles, stables, under planks and elsewhere. Cement the openings in bamboos in houses or close with tin. Make notes on needed structural work. Do the work as thoroughly as possible.
[Signed]T. W. Jackson,
Medical Inspector in Charge of Plague Suppression.
Method of Procedure in Collecting and Forwarding Rats Suspected of Plague Infection to the Laboratory in Manila, P. I.—Rat catching,—trapping and poisoning,—is conducted in accordance with instructions contained in the Sanitary Inspector's Handbook (pp. 36, 37, 38) issued by the Bureau of Health.
Rats are collected in Manila and forwarded to the Bureau of Science for autopsy and for biologic examination for the presence of plague bacilli in the following manner:
The various groups of rat catchers are provided with receptacles (iron pails) and a supply of a mixture of kerosene, cresol and water (kerosene 10 parts, cresol 2 parts; water 88 parts).
In these vessels, filled with the pulicidal mixture, the rats are immersed, with a minimum amount of handling, as soon as they are found (whether in traps or dead from poison).
If captured alive they are killed and then promptly immersed. The mixture must be well shaken or stirred when used, as it separates upon standing. The immersion is, of course, for the purpose of destroying any fleas which may be present upon the captured rat.
A paper tag showing the date and the exact location of the place of capture, with the name or group number of the rat catcher, is next affixed to a foot or to the tail of the rat and firmly tied upon the same, where it remains until the rat cadaver is finally disposed of. This tag is a card of strong Manila paper and the record upon it is made with an ordinary lead-pencil, as both ink and indelible pencil marks are apt to become illegible from wetting, whereas lead-pencil marks are little affected thereby.
If desired, the disinfected tag in any given case of rat plague may be returned to the Bureau of Health, for identification, where an accurate record of every rat captured is kept.
After dipping and tagging, the rats are taken to a central point, again dipped, and placed in large, tightly-covered, galvanized iron cans, in which containers they are delivered to the laboratory by cart, once or twice daily.
The Case of Mr. C.—The following are the facts concerning the case of Mr. W. C., a prominent American resident of Manila who suffered and died from plague in 1914.
Mr. C., an editor, was taken ill with plague on the night of September 18, sought medical advice and entered St. Paul's Hospital September 19, and was transferred to San Lazaro Hospital, September 20, with an established clinical and bacteriologic diagnosis of bubonic plague. He survived till September 22.
Upon September 21, in the course of disinfecting the business office of Mr. C., located in a district which had furnished a number of cases of both rat and human plague, a dead rat, mummified, was found in the right hand drawer of his desk and fleas were seen to hop from the drawer upon opening it.
A flea killed by the disinfecting mixture at this desk was identified at the Bureau of Science as a rat flea (Xenopsylla cheopis).
The rat cadaver was sent to the Bureau of Science and the following facts were reported from there some days later:
The mummified rat and skeleton were pulverizedin a sterile mortar and an emulsion was made and injected into guinea-pigs. The animals died from plague in a few days and plague bacilli were recovered from the tissues, as well as from the rat cadaver, by culture.
A second rat cadaver, found at the same time in the same building, during cleaning operations, was similarly treated with identical results.
There could scarcely be a stronger chain of convincing evidence against the rat and the flea, nor a more complete and convincing explanation of Mr. C.'s death than that afforded by these established facts and official documents. So far as I know there is no more striking case on record in the modern history of plague.
Letter of Warning and Appeal.—The following letter of warning and appeal for coöperation was suggested and framed by me February 10, 1914, at the time that extensive rat plague was discovered in the heart of the business district of Manila. I presented it to the Director of Health with a strong recommendation for approval and publication and after consideration he approved and authorized publication upon February 10. No change was made in the wording of the proclamation,but it was issued over the signature of the Director of Health to give added force and authority to the appeal. The results were, as I had hoped they might be, highly beneficial. The taking of the public into the confidence of the health authorities brought about a coöperation, without which our efforts in this difficult situation would have been sadly handicapped. It is my belief that this method should often be used by health authorities, particularly where an intelligent community is threatened.
To Whom It May Concern:You are hereby informed that the district bounded by Calles Rosario, Juan Luna, Dasmariñas and Plaza Calderon (and possibly the neighborhood bordering upon this congested district) is a dangerous one for all persons living or conducting business therein, on account of the presence there of extensive rat plague. Six human cases (with five deaths) have recently developed there and many dead rats have been found. All human cases have been directly traced to rats dead from plague.The Bureau of Health is now doing everything within its power to make this district safe, but the attention of all citizens, property owners and tenants is called to the fact that they are required by law to keep their premises free from rats and to abolish all structural conditions of the buildings which favor the harboring of rats. This means rat-proofing, and owners are earnestly urged toperform this necessary work now, under the direction of the Bureau of Health.As a temporary expedient and safeguard all interiors, walls, floors and ceilings should be sprayed with kerosene daily, or at intervals of two days, to kill the fleas which carry plague from rats to human beings. All dark insanitary places used for living rooms should be vacated at once; all merchandise should be piled upon trusses at least a foot above the floor; all straw, shavings and other material attractive to rats for nesting, should be removed and burned and all food materials upon which rats may feed and live should be placed in covered boxes, bins or cans.All rat-holes should be permanently closed and all broken cement or masonry should be repaired.Observance of these instructions may save the lives of yourselves, your families and your tenants. It is your duty to do your part in this matter, a part which neither the Bureau of Health nor the Government can do for you.Through very great effort the Bureau of Health has controlled plague in Manila and the Philippine Islands during the last two years.Residents must now do their part, and owners of property must permanently make their buildings safe for tenants, both for business and residential purposes.
To Whom It May Concern:
You are hereby informed that the district bounded by Calles Rosario, Juan Luna, Dasmariñas and Plaza Calderon (and possibly the neighborhood bordering upon this congested district) is a dangerous one for all persons living or conducting business therein, on account of the presence there of extensive rat plague. Six human cases (with five deaths) have recently developed there and many dead rats have been found. All human cases have been directly traced to rats dead from plague.
The Bureau of Health is now doing everything within its power to make this district safe, but the attention of all citizens, property owners and tenants is called to the fact that they are required by law to keep their premises free from rats and to abolish all structural conditions of the buildings which favor the harboring of rats. This means rat-proofing, and owners are earnestly urged toperform this necessary work now, under the direction of the Bureau of Health.
As a temporary expedient and safeguard all interiors, walls, floors and ceilings should be sprayed with kerosene daily, or at intervals of two days, to kill the fleas which carry plague from rats to human beings. All dark insanitary places used for living rooms should be vacated at once; all merchandise should be piled upon trusses at least a foot above the floor; all straw, shavings and other material attractive to rats for nesting, should be removed and burned and all food materials upon which rats may feed and live should be placed in covered boxes, bins or cans.
All rat-holes should be permanently closed and all broken cement or masonry should be repaired.
Observance of these instructions may save the lives of yourselves, your families and your tenants. It is your duty to do your part in this matter, a part which neither the Bureau of Health nor the Government can do for you.
Through very great effort the Bureau of Health has controlled plague in Manila and the Philippine Islands during the last two years.
Residents must now do their part, and owners of property must permanently make their buildings safe for tenants, both for business and residential purposes.
Bacteriologic Observations Made by Dr. Otto Schöbl.—The following observations upon the bacteriologic aspect of the Manila epidemic which we are considering were made by Dr. Otto Schöbl of the Biological Laboratory of the Bureau of Science, Manila, and pertain to the cases of thefirst year of the epidemic. They were printed in the December number of thePhilippine Journal of Sciencein 1913, but as they belong so definitely to the epidemic I am describing and as Dr. Schöbl has expressed his willingness for me to quote them in full, I gladly accept his permission. Dr. Schöbl advanced the possibilities of blood-culture diagnosis to such a point of reliability that it became practically possible for us to expect positive culture in nearly every case of true plague and the whole matter of bacteriologic diagnosis was perfected to a high degree of efficiency under his administration of the laboratory work.
He relates his observations as follows:
During the recent outbreak of plague in Manila, I had the opportunity to make certain observations which are of interest. These observations were made in the examination of: (1) Specimens taken from patients and from dead bodies at autopsies, (2) samples of blood-sucking insects collected in houses where plague patients had lived, (3) rodents caught by trap or poisoned in the parts of the city where plague cases occurred from time to time, and (4) domestic animals suspected of plague infection.I.Bacteriological Examination of Plague PatientsIn order to secure as early diagnosis as possible, the following procedure of investigation was adopted:The bubo was aspirated by means of a sterile hypodermicsyringe. The material thus obtained was placed in the water of condensation of an agar-slant culture tube.At least 7 centimetres of blood were withdrawn from thecubitalvein by means of another sterile syringe, and 5 centimetres of it were placed in an Erlenmeyer's flask, containing 200 centimetres of neutral meat broth. The rest of the blood was emptied into a sterile tube, and used for agglutination tests.Cultures obtained by this method were examined microscopically, and the growths on various culture media were studied. Gram stain, Löffler's methylene blue, and hanging-drop method were used. Polar-staining and chain formation in liquid media and the characteristic type of colony on the surface of agar were looked for. Animal inoculation was performed in every case, and the culture isolated from each case was identified by agglutination test, rabbit's immune serum being used.The results of the bacteriological examination of a series of 24 patients are tabulated in the two following tables.Table Iincludes the fatal cases andTable IIthose cases which recovered.The diagnosis of plague could be safely made from the microscopical examination of the liquid aspirated from the bubo in the majority of the cases. However, in certain instances the amount of the aspirated fluid being small and the bacilli very few, it was impossible to diagnose the case, especially when the cultures from the bubo were negative. Repeated examination of the patient was necessary under those conditions, but it happened in cases 22 and 23 that the patients died of plague before a second examination could be made. The smears and cultures from case 22 remained sterile, while the smears and cultures
During the recent outbreak of plague in Manila, I had the opportunity to make certain observations which are of interest. These observations were made in the examination of: (1) Specimens taken from patients and from dead bodies at autopsies, (2) samples of blood-sucking insects collected in houses where plague patients had lived, (3) rodents caught by trap or poisoned in the parts of the city where plague cases occurred from time to time, and (4) domestic animals suspected of plague infection.
I.Bacteriological Examination of Plague Patients
In order to secure as early diagnosis as possible, the following procedure of investigation was adopted:
Cultures obtained by this method were examined microscopically, and the growths on various culture media were studied. Gram stain, Löffler's methylene blue, and hanging-drop method were used. Polar-staining and chain formation in liquid media and the characteristic type of colony on the surface of agar were looked for. Animal inoculation was performed in every case, and the culture isolated from each case was identified by agglutination test, rabbit's immune serum being used.
The results of the bacteriological examination of a series of 24 patients are tabulated in the two following tables.Table Iincludes the fatal cases andTable IIthose cases which recovered.
The diagnosis of plague could be safely made from the microscopical examination of the liquid aspirated from the bubo in the majority of the cases. However, in certain instances the amount of the aspirated fluid being small and the bacilli very few, it was impossible to diagnose the case, especially when the cultures from the bubo were negative. Repeated examination of the patient was necessary under those conditions, but it happened in cases 22 and 23 that the patients died of plague before a second examination could be made. The smears and cultures from case 22 remained sterile, while the smears and cultures
Table I.—Examination of Fatal Cases of Plague
[A]Months.
Table II.—Examination of Plague Patients Who Recovered
Note.—The bubo in Nos. 2, 5, and 24 never opened spontaneously. The pus was aspirated at the time of the second, eventually third, examination. Nos. 11 and 19 opened spontaneously. A fistula formed along the canal which was caused by the puncture, and healed up in several weeks. Hard inguinal buboes of secondary order persisted in patient 19 at the time of second examination. No plague bacilli were found either in the bubo of the first or second order. Patient 20 had a considerable amount of pus in the inguinal primary bubo, but it was not opened until after the last examination.made from the swelling on the neck of patient 23 revealed the presence of pneumococci. Both patients died of plague, as was ascertained by examination of the organs after death.
Note.—The bubo in Nos. 2, 5, and 24 never opened spontaneously. The pus was aspirated at the time of the second, eventually third, examination. Nos. 11 and 19 opened spontaneously. A fistula formed along the canal which was caused by the puncture, and healed up in several weeks. Hard inguinal buboes of secondary order persisted in patient 19 at the time of second examination. No plague bacilli were found either in the bubo of the first or second order. Patient 20 had a considerable amount of pus in the inguinal primary bubo, but it was not opened until after the last examination.made from the swelling on the neck of patient 23 revealed the presence of pneumococci. Both patients died of plague, as was ascertained by examination of the organs after death.
Two of the patients, cases 8 and 12, had numerous plague bacilli in the sputum at the time when the expectoration showed the presence of blood (twenty-three and one-half and eighty-two hours, respectively, before death). In 3 cases I was able to prove the presence ofBacillus pestisin the skin lesions,intra vitam, fifteen, twenty-two, and forty-eight hours, respectively, before death. In case 18 there was no doubt that the skin lesions, which covered the whole body and the face, were of secondary nature, as the patient died shortly afterward. It was undoubtedly a case similar to those reported by Gotschlich and Zabolotny.[5]In the other two patients there was only 1 maculopapulous efflorescence on the foot in case 1 (with a corresponding femoral bubo) and 2 lesions of the same type on the arm and forearm in case 4 (with a corresponding axillary bubo). It is possible that these lesions were the original port of entry of infection. Numerous plague bacilli were found in the skin lesions of these cases, both microscopically and in culture.[5]Kolle und Wassermann: Handbuch der pathogenen Mikroorganismen. Gustav Fischer, Jena (1903),2, 521.The plague patients tabulated inTable IIrecovered. They were all treated with antiplague serum. While cases 5, 11, 19, and 24 appeared clinically to be rather severe, cases 2 and 20 were mild.It can be seen from thetablethat the plague bacilli may not be detected in the enlarged gland at first (case 2) and that their presence may be revealed only after repeatedexamination of the bubo. It is also evident from the results of repeated examinations that the plague bacilli disappear from the infected gland in a comparatively short time, as a rule at the time when pus starts to form. Contrary to the findings in patients who died, distinct phagocytosis was noticed in the smears made from the aspirated liquid in those patients who recovered and who had been treated with serum soon after the onset of the disease. It is undoubtedly this process that clears the gland of the infectious agents.The general opinion in regard to the presence ofBacillus pestisin the circulating blood seems to have been, as Thompson remarks, that "the bacillus is rarely to be found in the peripheral blood stream before the agonal stage."[6][6]Journ. Hyg., Cambridge (1906),6, 558.The Austrian Commission, using few drops of blood, found positive blood culture in 40 per cent; Calvert in Manila in 100 per cent when examined twenty-four hours before death; Choksy, Berestneff, and Mayr in 45 per cent; and Greig in 60 per cent. The Indian Commission examined 28 patients, and obtained positive blood cultures in 16 out of 23 fatal cases. Not a single positive blood culture was obtained from the patients who survived. The time of blood examination in positive cases was three and one-half to seventy-five and one-half hours before death. The amount of blood used was 1 cubic centimetre. Only 6 out of the 30 samples, which gave positive blood culture, were found positive by microscopical examination of blood smears. The following conclusions are based on these observations in regard to the septicæmic stage of bubonic plague: (1) "A severe septicæmia maybe present at a comparatively early stage of the disease and for a considerable number of hours before death, and (2) the septicæmia may be of an irregular and fluctuating type."[7][7]Ibid.(1907),7, 395.From thetablesit will be seen that out of 15 patients examined by me, 14 gave positive blood culture; and of these 3 recovered. One blood culture revealed the presence of streptococcus in addition toBacillus pestis. The results of the examinations tabulated inTables IandIIshow, in agreement with the findings of the Indian Commission, the occasional early occurrence of plague bacilli in the blood stream, as the time of examination in the positive cases varied from one hour to one hundred six hours before death. In consideration of the ephemeral character of the septicæmic stage of plague, as evidenced by repeated blood cultures in the three patients who recovered, one can hardly avoid the impression that there is a certain degree of septicæmia in every case of plague. The possibility of detecting the bacillus in the circulating blood increases in proportion with the quantity of blood used for culture. The best chance to recover plague bacilli from the circulating blood seems to be in the stage of high fever and general prostration.The phenomenon of agglutination of plague bacilli by the serum of patients was first observed by Wissokowitsch and Zabolotny in 1897[8] and later confirmed by the German Plague Commission. Vagedes, Klein, and others[8]pointed out the defects of the reaction as a diagnosticmeans. Aside from the technical difficulties, the reaction was found inconstant, and its occurrence was not noticed until the second week of the disease and even then only in low dilutions of the serum.[8]Referred to in Kolle und Wassermann: Handbuch der pathogenen Mikroorganismen (1903),2, 524.Although the recent work of Strong[9]and of Strong and Teague[10]has reduced the technical difficulties, the fact remains that positive agglutination of plague bacilli by the patient's serum cannot be obtained in the first week of the disease, and, therefore, the isolation of plague bacilli from the body of the patient is still the only quick and safe method of plague diagnosis.[9]The Philippine Journal of Science, Sec. B. (1907),2, 155.[10]Ibid.(1912),7, 194–201.Having utilized the technic devised by Teague, I have had no difficulty in performing the agglutination test in plague. The emulsion of plague bacilli, to be used for the test, was prepared by suspending young cultures of virulent plague bacilli, grown at 30° C., in salt solution and filtering the suspension through filter paper. No antiseptic was added nor heat applied. Serial dilutions of unheated patient's serum were mixed with equal amounts of bacterial suspension in small test tubes. Incubation at 35° C. followed. Controls, consisting of serial dilutions of normal human serum as well as bacterial suspensions without serum, excluded any possible error which might have been caused by spontaneous sedimentation of the bacterial suspension; while a parallel test with highly agglutinant serum facilitated the reading of positive results.Altogether, 22 tests were performed on 15 patients, 11 of whom were fatal cases and 4 of whom recovered.In the negative reactions, the duration of the disease at the time of examination ranges from two to six days. The non-fatal cases showed slight agglutination from the sixth day on. From that day, the agglutination titer of the serum was found to rise, and the agglutinins persisted in the blood of convalescents up to the seventh week of the disease.[11][11]It is hoped that it will be possible to examine some of the survivors for agglutination from time to time.It must be borne in mind that the patients, who showed positive agglutination, had been vigorously treated with antiplague serum. Nevertheless, in consideration of the low titer of the curative serum (dilution 1:32, agglutination positive; dilution 1:64, agglutination negative), the rise of the agglutinant power of the patient's serum in dilutions higher than 1:16 cannot be explained as wholly due to passive immunity, but rather to active immunity arrived at on the principle of simultaneous immunization.From the preceding observations the following conclusions are drawn:The importance of blood cultures as a diagnostic means is evident from the fact that positive blood culture was obtained in practically every case that was examined in the febrile stage of the disease, even when buboes or signs of pulmonary involvement had not been detected clinically.It is also evident thatBacillus pestismay be found in the circulating blood of the patients even in cases which subsequently recover.The period of time during whichBacillus pestiscirculates in the blood is evidently short and irregular.Mixed infection may be encountered in plague septicæmia (Streptococcus,Pneumococcus).The agglutination test is of no value for the diagnosis of plague, as it was found positive only in convalescents.Phagocytosis of plague bacilli in the bubo was noticed only in patients who recovered after being vigorously treated with curative serum.The presence of numerous plague bacilli in comparatively insignificant skin lesions during the life of the patient points to the possibility of direct transmission, while the fact that a patient without any apparent bubo, who is not so sick as to be detained from his daily occupation, may expectorate large numbers of plague bacilli, are facts of great importance with regard to the communication of the disease. It is obvious that the last-mentioned condition might, and very likely does, give rise to an epidemic of pneumonic plague if the atmospheric and sanitary conditions are favorable.Table III.—Insects Found to Contain Bacillus PestisAuthorInsectSource of infectionExperimental transmissionYersinFliesLaboratory infectionNuttalFliesExperimental infectionNuttalBedbugsExperimental infectionNegative by bite.NuttalFleaExperimental infectionNegative.HankinAnt's fæcesFed on plague materialHankinBedbugsPlague hospitalOgataFleaPlague ratsSimondFleaPlague rats, experimentalPositive.Tindswell, 1900FleaPlague ratsNegative.Tindswell, 1903FleaPlague ratsNegative.KolleFleaExperimental infectionNegative.Gauthier and RaybaudFleaExperimental infectionPositive.ListonFleaEpidemic among pigs; harbored fleas; dead rats foundPositive.ZiroliaFleaRetainedBacillus pestis, 7–8 daysBritish CommissionFleaRepeated experimentsPositive.VerbijtskiFlea and bedbugExperimental infectionPositive.La Bonadière and XanthopulidesFlyHerzogPediculus capitisDead body of a plague caseII.Observations on the Transmission of Plague By Blood-sucking InsectsJudging from the data which have been collected from the literature[12]on the transmission of plague (Table III), Simond seems to have been the first to call attention tothe important part which blood-sucking insects, particularly fleas, play in the transmission of plague. Although many investigators have been successful in demonstrating the presence ofBacillus pestisin the digestive system of blood-sucking insects, it was not until the experiments of Gauthier and Raybaud that the actual transmission of plague infection by fleas was convincingly proved. Ever since the exhaustive and conclusive experiments, which were carried out both under natural and artificial conditions by the British Plague Commission, and the work of Verbijtski, which antedates the British Commission, were presented, there has been no doubt that the transmission of plague by blood-sucking insects, particularly by the fleas, is one, although not the only, mode of spreading this disease. It is obvious, as Herzog correctly remarks, that the factors which are responsible for the spreading of plague must be considered individually in each epidemic and in various parts of the world as well. There is no doubt that the importance of any insect in the transmission of plague depends on its habits as well as on those of the host, be it either animal or man.[12]Centralbl. f. Backt., 1 Abt. (1897),22, 87, 437. Report of Indian Plague Commission (1898–99). Zeitschr. f. Hyg. u. Infectionskrankh. (1901),36, 89. Kolle und Wassermann: Handbuch der pathogenen Mikroorganismen (1903),2, 538. Zeitschr. f. Hyg. u. Infectionskrankh. (1905),51, 268. Journ. Hyg., Cambridge (1907–10), plague numbers.Ibid.(1908),8, 162, 260.
Two of the patients, cases 8 and 12, had numerous plague bacilli in the sputum at the time when the expectoration showed the presence of blood (twenty-three and one-half and eighty-two hours, respectively, before death). In 3 cases I was able to prove the presence ofBacillus pestisin the skin lesions,intra vitam, fifteen, twenty-two, and forty-eight hours, respectively, before death. In case 18 there was no doubt that the skin lesions, which covered the whole body and the face, were of secondary nature, as the patient died shortly afterward. It was undoubtedly a case similar to those reported by Gotschlich and Zabolotny.[5]In the other two patients there was only 1 maculopapulous efflorescence on the foot in case 1 (with a corresponding femoral bubo) and 2 lesions of the same type on the arm and forearm in case 4 (with a corresponding axillary bubo). It is possible that these lesions were the original port of entry of infection. Numerous plague bacilli were found in the skin lesions of these cases, both microscopically and in culture.
[5]Kolle und Wassermann: Handbuch der pathogenen Mikroorganismen. Gustav Fischer, Jena (1903),2, 521.
The plague patients tabulated inTable IIrecovered. They were all treated with antiplague serum. While cases 5, 11, 19, and 24 appeared clinically to be rather severe, cases 2 and 20 were mild.
It can be seen from thetablethat the plague bacilli may not be detected in the enlarged gland at first (case 2) and that their presence may be revealed only after repeatedexamination of the bubo. It is also evident from the results of repeated examinations that the plague bacilli disappear from the infected gland in a comparatively short time, as a rule at the time when pus starts to form. Contrary to the findings in patients who died, distinct phagocytosis was noticed in the smears made from the aspirated liquid in those patients who recovered and who had been treated with serum soon after the onset of the disease. It is undoubtedly this process that clears the gland of the infectious agents.
The general opinion in regard to the presence ofBacillus pestisin the circulating blood seems to have been, as Thompson remarks, that "the bacillus is rarely to be found in the peripheral blood stream before the agonal stage."[6]
[6]Journ. Hyg., Cambridge (1906),6, 558.
The Austrian Commission, using few drops of blood, found positive blood culture in 40 per cent; Calvert in Manila in 100 per cent when examined twenty-four hours before death; Choksy, Berestneff, and Mayr in 45 per cent; and Greig in 60 per cent. The Indian Commission examined 28 patients, and obtained positive blood cultures in 16 out of 23 fatal cases. Not a single positive blood culture was obtained from the patients who survived. The time of blood examination in positive cases was three and one-half to seventy-five and one-half hours before death. The amount of blood used was 1 cubic centimetre. Only 6 out of the 30 samples, which gave positive blood culture, were found positive by microscopical examination of blood smears. The following conclusions are based on these observations in regard to the septicæmic stage of bubonic plague: (1) "A severe septicæmia maybe present at a comparatively early stage of the disease and for a considerable number of hours before death, and (2) the septicæmia may be of an irregular and fluctuating type."[7]
[7]Ibid.(1907),7, 395.
From thetablesit will be seen that out of 15 patients examined by me, 14 gave positive blood culture; and of these 3 recovered. One blood culture revealed the presence of streptococcus in addition toBacillus pestis. The results of the examinations tabulated inTables IandIIshow, in agreement with the findings of the Indian Commission, the occasional early occurrence of plague bacilli in the blood stream, as the time of examination in the positive cases varied from one hour to one hundred six hours before death. In consideration of the ephemeral character of the septicæmic stage of plague, as evidenced by repeated blood cultures in the three patients who recovered, one can hardly avoid the impression that there is a certain degree of septicæmia in every case of plague. The possibility of detecting the bacillus in the circulating blood increases in proportion with the quantity of blood used for culture. The best chance to recover plague bacilli from the circulating blood seems to be in the stage of high fever and general prostration.
The phenomenon of agglutination of plague bacilli by the serum of patients was first observed by Wissokowitsch and Zabolotny in 1897[8] and later confirmed by the German Plague Commission. Vagedes, Klein, and others[8]pointed out the defects of the reaction as a diagnosticmeans. Aside from the technical difficulties, the reaction was found inconstant, and its occurrence was not noticed until the second week of the disease and even then only in low dilutions of the serum.
[8]Referred to in Kolle und Wassermann: Handbuch der pathogenen Mikroorganismen (1903),2, 524.
Although the recent work of Strong[9]and of Strong and Teague[10]has reduced the technical difficulties, the fact remains that positive agglutination of plague bacilli by the patient's serum cannot be obtained in the first week of the disease, and, therefore, the isolation of plague bacilli from the body of the patient is still the only quick and safe method of plague diagnosis.
[9]The Philippine Journal of Science, Sec. B. (1907),2, 155.
[10]Ibid.(1912),7, 194–201.
Having utilized the technic devised by Teague, I have had no difficulty in performing the agglutination test in plague. The emulsion of plague bacilli, to be used for the test, was prepared by suspending young cultures of virulent plague bacilli, grown at 30° C., in salt solution and filtering the suspension through filter paper. No antiseptic was added nor heat applied. Serial dilutions of unheated patient's serum were mixed with equal amounts of bacterial suspension in small test tubes. Incubation at 35° C. followed. Controls, consisting of serial dilutions of normal human serum as well as bacterial suspensions without serum, excluded any possible error which might have been caused by spontaneous sedimentation of the bacterial suspension; while a parallel test with highly agglutinant serum facilitated the reading of positive results.
Altogether, 22 tests were performed on 15 patients, 11 of whom were fatal cases and 4 of whom recovered.In the negative reactions, the duration of the disease at the time of examination ranges from two to six days. The non-fatal cases showed slight agglutination from the sixth day on. From that day, the agglutination titer of the serum was found to rise, and the agglutinins persisted in the blood of convalescents up to the seventh week of the disease.[11]
[11]It is hoped that it will be possible to examine some of the survivors for agglutination from time to time.
It must be borne in mind that the patients, who showed positive agglutination, had been vigorously treated with antiplague serum. Nevertheless, in consideration of the low titer of the curative serum (dilution 1:32, agglutination positive; dilution 1:64, agglutination negative), the rise of the agglutinant power of the patient's serum in dilutions higher than 1:16 cannot be explained as wholly due to passive immunity, but rather to active immunity arrived at on the principle of simultaneous immunization.
From the preceding observations the following conclusions are drawn:
Table III.—Insects Found to Contain Bacillus Pestis
II.Observations on the Transmission of Plague By Blood-sucking Insects
Judging from the data which have been collected from the literature[12]on the transmission of plague (Table III), Simond seems to have been the first to call attention tothe important part which blood-sucking insects, particularly fleas, play in the transmission of plague. Although many investigators have been successful in demonstrating the presence ofBacillus pestisin the digestive system of blood-sucking insects, it was not until the experiments of Gauthier and Raybaud that the actual transmission of plague infection by fleas was convincingly proved. Ever since the exhaustive and conclusive experiments, which were carried out both under natural and artificial conditions by the British Plague Commission, and the work of Verbijtski, which antedates the British Commission, were presented, there has been no doubt that the transmission of plague by blood-sucking insects, particularly by the fleas, is one, although not the only, mode of spreading this disease. It is obvious, as Herzog correctly remarks, that the factors which are responsible for the spreading of plague must be considered individually in each epidemic and in various parts of the world as well. There is no doubt that the importance of any insect in the transmission of plague depends on its habits as well as on those of the host, be it either animal or man.
[12]Centralbl. f. Backt., 1 Abt. (1897),22, 87, 437. Report of Indian Plague Commission (1898–99). Zeitschr. f. Hyg. u. Infectionskrankh. (1901),36, 89. Kolle und Wassermann: Handbuch der pathogenen Mikroorganismen (1903),2, 538. Zeitschr. f. Hyg. u. Infectionskrankh. (1905),51, 268. Journ. Hyg., Cambridge (1907–10), plague numbers.Ibid.(1908),8, 162, 260.