Report of the Departmental Committee apointed to inquire as to precautions for preventing danger of infection from anthrax in the manipulation of wool, goat hair, and camel hair.
- Great Britain. Committee on Anthrax.
- Date:
- 1918
Licence: Public Domain Mark
Credit: Report of the Departmental Committee apointed to inquire as to precautions for preventing danger of infection from anthrax in the manipulation of wool, goat hair, and camel hair. Source: Wellcome Collection.
51/356 page 43
![central portion varied from that of a pin’s head upwards, but it was always possible to cultivate anthrax where it was observed. It was constantly noted that where the thickness of the remnant was less than a quarter of an inch (6 millimetres), the formaldehyde had’ penetrated to the ‘centre, the whole had been ‘converted’ to’ a tough leathery substance, and all anthrax spores were destroyed. In some cases, where the thickness of the remnant was about’a quarter of an inch (6} millimetres) or slightly over, it was found possible to’ cause one or two isolated colonies to grow out of minute particles of the tough leathery changed blood in the culttre medium after prolonged incubation. ‘When the thickness of the remnant appreciably exceeded a quarter of an inch, it was possible to discern a 1ed sisal and detached coloniés of anthtax appeared in the culture ‘medium. Three things are clear: (1) That formaldehyde possesses fairly considerable powers of penetration into the blood which remains after the preliminary part of the disinfection process. Penetration takes place during immersion in the formaldehyde solution, but whether it is continued in the drying process we made’ no experiments to ascertain (but see Professor Delepine’s report to the Sub-Committee, pp. 60 to 65 below). In the’ time ‘and under the con- ditions of the experiments the distance the formaldehyde penetrates into’ the blood measured from the outer surface is approximately’ one-eighth’ of!an inch (3:mmz.); so that remnants of bloodelots of less than one-quarter of an inch (6; mm.) in thickness are'completely penetrated: (2) In remnants of bloodclots a quarter of, an inch thick or moré the formaldehyde is not in sufficient, strength or (more probably) has not, owing to the time necessary for penetration, had sufficient time to cause destruction of all anthrax spores.at the end of drying. (3) The action of formaldehyde which has penetrated into blood is progressive and does not cease with. drying, so that if the, penetrated blood be allowed to stand, all anthrax spores surviving at the end of drying are in time destroyed. The limit of time necessary to permit/of the destruction of the surviving. spores was. not ascertained, but.Jjt‘is apparently less than three days in most. cases. This clearly. depends,: however, on: the thoroughness with- which penetration has taken: place. There were indications that. remnants of élots: somewhat larger; than those referred to’ above might. contain a few surviving spores after three days’ standing, but none after four or five days. This might be the interpretation of the results obtained in Experiments, 11];112,115 and116, in-which.by cultivation after 65-70..hours> standing a few surviving spores were found, while after a further 48 hours’ standing Professor Delépine was unable to find SUE ving infection by. animal inoculation. The penetrative and progressive action of formaldehyde Lt its effect on hidod are of the greatest importance. The complete removal of all protection from the spores must be aimed at in the preliminary process, yet it is possible that some fragments of blood may escape. _ If not too large, these will be penetrated completely by formaldehyde and will-be converted from the friable, easily broken up clot into tough leathery masses, in which, after a few days, the surviving spores will perish owing to the slow but eventually fatal action of the formaldehyde. In other words, ‘a safety factor of considerable value is provided. 12. OTHER: EXPERIMENTS. “Tn addition -to the experiments Agen discussed and experiments on the commercial scale to be presently described, numerous others were carried out. Of these, the following | are of importance :—— (a) Experiment 146. -—-In pido to gain some idea of the degree of infection remaining in the bloodclots after the preliminary treatment, a bloodelot of: series C, (citrated. blood). was treated for three periods of 15 minutes in water at 102° F., each period being followed by squeezing through rollers. The wool was then practically free from blood, and was placed in ammonia solution and cultures, made the same day... The number of colonies of anthrax bacilli which developed on the culture plates was enormous, and, the result indicated. that: the wool after washing, even when freed from blood, may still be very highly infected. ‘This was to be expected, but the demonstration of the fact is worthy of being placed on record,.as it incidentally affords a complete explanation of the abundance in which anthrax bacilli. may oecasionally be grown from certain raw materials, such as Hast Indian goat hair, entirely free from blood. , ct epdhe, Sub-Committee was approached by the proprietors of “ bacterol,”’ a disinfecting preparation. of which formaldehyde is a eonstituent, with a view to making experiments with this substance by means of the apparatus and accor ding to the method advocated by them.. : It, was claimed that ‘“bacterol”. when so used has: great powers of penetration, whereby the complete destruction, of anthrax spores, even. when embedded in hard dry blood, could’ be ensured. Anxious to’ try any method offering prospects of success, we arranged that Messrs. Bacterol, Ltd., should send their, representative to Bradford: with. their apparatus: This they .did¢ and the following. experiments» were cafried- out by him. » The apparatus: consisted of a chamber having four shelves.of: perforated metal;.each capable of holding about 40 lbs. of mohair. . To. the. outside of the chamber a“vaporiser was fitted, consisting of a’ ‘strongly heated coil, through which’ the bacterol (a liquid) flowed, under. pressure, from a container,, The vapour.was admitted to the chamber through two pipes,,one entering below G2](https://iiif.wellcomecollection.org/image/b32178049_0051.jp2/full/800%2C/0/default.jpg)
