Complete Text (Part 20)

261 Latin, preferabh' a noun, in tlie nominative, singu- lar: it should be invariably spelled with a capital letter. Ex.: Ascaris or Culex. 9. Species — the division next below the Genus. It consists of animals in all respects alike or which differ in only minor details. (The male and female of a species may be unlike, but in mating they pro- duce young having characteristics similar to those of the parents.) The specific name should be : 1. A noun in the genitive, or 2. An adjective, which should agree in gender, case and number with the generic name. (Ex- ception— may have a masculine noun as the specific with a feminine generic name.) 3. A modern patronymic — = Complete name plus i for a man. = Complete name plus ac for a woman. 4. Always spelled with a small letter. In naming a species, the name of the genus is always written first, with a capital letter, followed by the specific or descriptive term, with a small let- ter. When 'printed^ both should be in italics; when tvritten^ both are underscored — Ex.: Ascaris himhricoides or Musca domestica. Type Species — the species of a genus always re- ferred to as representing the genus. Other species may, for good reasons, be transferred to another genus, but the type species is permanently in the genus. Many favor reduplication in the naming of the t^'pe species, as Heteropliyes heteropliyes. USEFUL BIBLIOGRAPHY IN PARASITOLOGY. 1. C. W. Stiles- Articles in Osier's Modern Medicine. 2. Minchen— An Introduction to the Stud}^ of Protozoa. 262 3. G. W. Calkins— rrotozooclogy. 4. Doflein— Lehrbnch der Protozoenkunde, 3rd Edition. 5. Y. Prowazek — Handbiicli der patliogenen Protozoen. 6. Kolle U. Wassermann — Handbucli der patliogenen Mikroorganismen. (Edition, Vol. VIL). 7. Braun — The Animal Parasites of Man. 8. Fantham, Stephens and Theobald — , The Animal Parasites of Man. 9. Blanchard — Traite de Zoologie Medicale. 10. Leuckart — ■ Die Parasiten des Menschen. 11. Stitt— Practical Bacteriology, Blood Work and Ani- mal Parasitology, 1th Edition; Diagnostics and Treatment of Tropical Diseases. 12. Castellani and Chalmers — Mannal of Tropical Medicine, 2nd Edition. 13. Patrick Manson — Tropical Diseases, 5th Edition. 14. Mense — • Handbuch der Tropenkrankheiten, 2nd Edi- tion. 15. Herms — ■ Medical and Veterinary Entomology. CLASSIFICATION OF THE MORE IMPORTANT PARASITES OF MAN. Group I. — Protozoa (Phylum). Class A. — Rhizopoda or Sarcodma. A class of Protozoa whose functions of locomotion and prehension are performed by temporary protru- sions of protoplasm called pseudopodia. 263 A. Order — Gymxamoeba. (Jc'iius — Endiunoclja. Species : 1. E. coli — uoii-patliogeuic. 2. E. liistoUjiica — (Includes E. tetragena) — Amoebic clyseutery; Liver abscess. Class B. — FJagellata or Mastigopliora (to wear a whip ) . A class of Protozoa in which flagella or undulat- ing membranes serve the functions of locomotion and prehension. ' (1). Genus — Spirochaeta or Spiroscliaudiiuiia. Speci-es : 1. S. rccurroitic — (S. obermeieri) — European relapsing fever.- | 2. S. duttoiii — African relapsing fever. 3. ^. cartcri — Asiatic relapsing fever. 4. S. novyi — American relapsing fever. 5. ^. refringens. 6. S. vuiccnti — Vincent's angina. (2) Genus — Treponema. Species : 1. T. pallidum — Syphilis. 2. T. pertenue — Yaws. (8) Genus — Trypanosoma. Species : 1. T. qanMense. ) ^^ . . , ^ „ , ^ . V Sleeping sickness. 2. T. rJwdesiense j ( 4 ) Genus — Sch izotrypa num. Species : 1, S. cruzi — Brazilian tiwpanosomiasis. ( 5 ) Genus — Leishm a nia . Species : 1. L. donoixini — Kala-azar. 2. L. tropica — Oriental sore. 3. L. infantum — Infantile splenomegaly. (6) Genus — Balyesia. 264 Species : 1. B. higcmina — {Piroplasma higeminum) — Texas fever of cattle or Ked water fever. (7) Genus — Trichomonas. Species : 1. T. vaginalis. 2. T. intestinals. Flagellate diarrhoea. (8) Genus — Lamhlia. Species : 1. L. intestinalis. Flagellate diarrhoea. (9) Genus — Cercomonas. Species : 1. C. hominis. Flagellate diarrhoea. Class C. — Infusoria or Ciliata. A class possessing contratile vacuoles and numer- ous fine cilia which are shorter than fiagella and Jiave a sweeping stroke. A. Order — Heterotricha. Genus — Balantidium. Species : 1. B. coli. Class D — Sporozoa. These possess no motile organs. They live as para- sites in tissues and cells of other animals. Keproduc- tion by spores.- A. Order — Coccidaria. (1) Genus — Eimeria. Species : 1. E. stiedae. (2) Genus — Isospora — Luci. Species: 1. /. J)igemina. 265 B. Order — Haemosi'ORIdia. GeiiiiH — Plasmodium. Species : 1. P. vivax — Terian malaria. 2. P. malariae — Quartan malaria. 3. P. falciparum — (Laverania malariae) — AestiA'o-autumnal malaria. c. Order — Sarcosporidia. Genus — Sarcocystis — Stuntu etaoin Species : 1. S.— ?. Group II. — Vermes (Phylum) worms. Class A. — Platyhelminthes or Platodes. Flat worms. Divided into two main orders. A. Order — Trematoda or Trematodes. Flukes — possess intestine, but no anus; one or two suckers present: body never segmented nor cili- ated. Order divided into three main families. 1. Fasciolidae (family). Two suckers, one terminal, the other adjacent to it; situated ventrally; hermaphroditic. (1) Genus — Fasciola. Species : 1. F. hepatica — Liver fluke disease — Hepa- tic distomiasis. (2) Genus — Fasciolopsis. Species : 1. F. 'buskii — Intestinal distomiasis. (3) Genus — Dicrocoelium. Species : 1. D. lanceatum — He}3atic distomiasis. (4) Genus — Parngonimus. Species : 1. P. iv ester manii — Pulmonary distomiasis — Parasitic haemoptysis. (5) Genus — Clonorchis. I 266 impedes : 1. C. Hnivii^ls — Japanese liver (luke disease. (<)j Genus — 0 pi sth orchis. Species : 1, 0. felineus — Siberian liver fluke disease. (7j Genus — HeteropTiyes. Species : 1. H. lieteropJiyes — Intestinal distomiasis. 2. Paramphistomidae (family). Two suckers, one at either extremity ; hermaphro- ditic. (1) Genus — Gastrodiscus. Species : 1. G. hominis — Intestinal distomiasis. 3. Schistosomidae (family). Leaf-like male which by a folding-in of its sides makes a channel for the thread-like female. Sexes separate. (1) Genus — Schistosoma. Species : 1. S. haematoMum — (African blood fluke). 2. S. japonicum — (Asiatic blood fluke). 3. S. mansoni — (West Indian blood fluke). B. Order — Cestoda. Tapeworms; intestine absent; 2 to 4 suckers on head; adult body segmented and parasitic in intes- tine; larvae are parasitic elsewhere. Two main families. 1. Taeniidae (family). Head with four cup-like suckers; genital pores lateral. (1) Genus — Taenia. Species : 1. T. solium — (Pork or armed tapeworm). 2. T. saginata — (Beef or unarmed tape- worm ) . Hydatid disease. 267 (2) Genus — DipijUcUiiiH. Species : 1. D. caninnni — {Tdcnia cucumerUia ; the double pored or dog tapeworm). (3) Geuus — Hytnenolepis. Species : 1. H. nana — {Taenia ;/(///(/; the dwarf tape- worm). 2. H. ditnijiuta — {Taenia diniinuta ; Hijme nolepis flavopiuictata ; the rat tape- worm ) . 2. Dihoihriocephalidae (famihO. Head with two elongated slit-like suckers ; median genital pores ; ventral, median, rosette uterns ; single set of genital organs in each segment. Genus — Dihothriocephalus. Species : 1. D. Jatus — (the broad or fish tapeworm). Class B. — Xemathelminthes. Round worms, covered with a cuticle which is often ringed ; well developed alimentary canal ; sexes are usually separated ; males smaller in size, posterior end curved or curled, sometimes show- ing umbrella-like swelling, the copulatory bursa ; genital opening in the male near anus, in female midway; develop as a rule in damp earth from the eggs as rhabditiform larvae; a few are vivi- parous. Families important to man are: A. Order — Xematoda or Nematodes. 1. FiJariidae (family). (1) Genus — Filaria. Species : 1. F. 'bancrofti — {F. sanguinis hominis; F. nocturna) — Filariasis ; Elephantia- sis (?). 2. F. loa. 3. F. perstans. 268 (2) (reuiLs — Dracuucnlu^. X peek's : 1. D. medinensis — Guinea worm ; "Fiery serpent" (?). Angiostomidoe (family) . Genus — Strougyloides. Species : 1. S. stercoralis — Cochin China diarrhea. Trichinellidae (family). ( 1 ) Genus — Trich inella. Species : 1. T. spiralis — [Trichina spiralis) ^Trichi- niasis. (2) Genus — Trichiuris. Species : 1. T. trichiura — (TricJwcephahis dispar ; whipworm). Strongylidae (family) . ( 1 ) Genus — Ancylo stoma. Species : 1. A. duodenale — Old World hookworm). Uncinariasis or Hookworm disease, (2) Genus — Xecator. Species : 1. Kecator americanus — (New World hook- worm). Uncinariasis or Hookworm dis- ease. ( 3 ) Genus — Trich ostrongylus: Species : 1. T. instahilis — Parasite of sheep and goats; accidental, but harmless parasite of man ; eggs may be mistaken for hook- worm ova. (4) Genus — Dioctophyme. Species : 1. D. renale — (Eustrongyliis gigas; the dog kidney Avorm). 269 5. Ascaridae (family). Xo intermediate host uecessary. (1) Genus — Ascaris. Species : 1. A. lunil))icoides — Eel worm) — Ascaria- sis. (2) Genus — Toxocara. Species : 1. T. canis — [Ascaris mijsfa.r; Toxascaris niystax ; Belascaris mystax ; the clog as- caris or eel worm ) . (3) Genus — Oxyuris s. 1. or Entei'ohius. Species : 1. 0. vennicularis — E. vevmicularis ; pin- worm or seatworm. . Group III. — Arthropoda (Phylum) — ( jointed-limbed invertebrates) . Class A. — Arachnoidea. (Resembling a spider.) These have the head and thorax fused together ; possess four pairs of am- bulatory appendages ; never have compound eves ; chitinous exoskeleton : no antennae ; body is often segmented ; respiration is by tracheal tubes. Those of chief interest belong to the general order Aca- rina, which includes chiefly the mites and /^^icArs. (1) GemvL'^-Sar copies. Species : 1. S. scahiei — (Itch mite) — Scabies or ''the itch." (2) Genus — Dcmodex. Species : 1. D. foUiculorum. (3) Genus — Leptus. Species : 1. L. autiuiinaJe — (Harvest bug or "chig- ger"). 270 Class B. — Jnsccta. Possess one pair of antennae, three pairs of month parts and three pairs of legs. The body is divided into tlu-ee parts — head, thorax and abdomen. Usn- ally have two pairs of wings. Most insects show metamorphosis ; ova develop into voracions, worm- like /(// vac; then follows the encased pupa stage, and this finally tnrns into an imago or fnlly de- veloped insect. The following are important in their relation to man : A. Order — Su'huxculata (Flat; Avingless ; no metamorphosis.) 1. Pcdiculidae (family). ( 1 1 (ienus — Pediculus. Species : 1. F. capitis — (Head lonse). 2, P. vestinicnti — (Body lonse). Pedicnlosis ( 2 j . ( ienus — Pli th irius. Species : 1. P. piihis — {Phthirius inguiiialis; Pedicu- lus piihis; Crab louse). Pediculosis. B. Order — Heimiptera or Khynchota. Insects possessing a sucking beak ; metamorphosis not marked. ]. Gimicidae (familj). Genus — Cimex. Species : 1. C. lectularius — (Acanthia lectularia; the bed-bug). c. Order — Siphoxaptera Laterally flattened, wingless insects which undergo complete metamorphosis. 1. Pulicidae (family). (1) Genus — Pulex. Species : 1. P. irritans — (European human flea), (2) i^^nw^-^Ctenoceplialus. 271 Species : 1. C. canis — [C. serratlceps; American dog and human flea). (3) Genus — ^arcopsylla. Species : 1. S. penetrans — (Pulex penetrans; Trop- ical sand flea; "chigger"). (4) Genus — Xenopsylla or LaemopsyUa. Species : 1. A^. chcopis — (LaemopsyUa clieopis ; rat flea of India; plague flea). (5) Genus — Ceratophyllus. Species : 1. C. fasciatus — (Rat flea.) D. Order — Diptera. Have distinct mouth parts — for biting or sucking ; undergo complete metamori^hosis ; possess one pair of wings ; other pair usually rudimentary. 1. Culicidae (family). (1) Genus — Culex. Species : 1. C. quinquefasciatiis — (C fatigans; House mosquito ) . Transmits : 1. Dengue fever. 2. FiJaria hancrofti. 3. Proteosoma infection of birds. (2) Aedes or Stegomyia. Species : 1. A. calopus — {Stegomyia calo pus; S. fas- ciataQ — Transmits fellow fever. (3) Anopheles. Species : 1. A. rnaciilipcnnis — Transmits malaria. 2. Muscidae (family). (1) Genus — Glossina. 272 Species : 1. G. palpalls — Transmits sleeping sickness Trypanosoina gamhiense. 2. G. morsitans — Transmits Trypanosoma rJiodcsiense and Trypcmesoma hrucei. (2) (lenus — Stomoxys. Species : 1. S. calcitrans — (Stable fly). ( :> ) Genus — Musca. Species : 1. M. domestica — (Common house fly). 273 En (la mocha histolytica. Two forms of the amoeba occur in the stools, the mobile and the encysted. In examining the feces for this organism it is best to pick out a bloody particle of mucns if such is present, make an emulsion with a small amount of salt solution upon a glass slide, place a cover-slip over it and examine Avith low pow- er for small retractile bodies. If such are found tlieu examine AvJtli the high power for confirmation and details. Wa'lker's table for dift'erentiating E. Coli and E. Histolytica. (Barker Vol. II. page 421.) Mobile stage. E. histolytica. 1. Appearance hyaline. 2. Kefractiveness more feeble. 0. Movements active in fresh stool. 4. Nucleus more or less indistinct. 5. Chromatin of nucleus scanty. E. coli. 1. Appearance porcelaneous. 2. Kefractiveness pronounced. 3. Movements sluggish. 4. Nucleus distinct. 5. Chromatin of nucleus abundant. Encysted Stage. E. histolytica. 1. Cyst smaller. • • • 2. Cyst less refractiAe. 3. Usualh^ contains elongated refraction bodies knoAvn as "chromidial bodies." 4. Nuclei never more than four. 5. Cvst wall thinner. 274 E. coll. 1. C^'St larger. 2. Cyst more refractive. 3. Cysts do not contain "cliromidial bodies.' 4. Nuclei 8, occasionally more. 5. Cvst wall thicker. In general it may be said that when one finds an amoeba with phagocyted r. b. c. one should suspect a pathogenic form. This does not always hold true but is fairly reliable. Coli may contain one or two, while histolytica usually contains a great many. Pathology — The amoeba attack most frequently the upper part of the large intestine, where tluy en- ter the crypts of the mucosa and produce small necrotic areas. From here they invade the sub- mucosa and undermine smaller or largr patches. The organism frequently find their way into the liver and produce abscesses tiiere. Diagnosis — The finding the amoeba in the stools. Trypanosoma gambiense. Size — 18 to 25 microns by 2 to 21/2 microui-'. Pathology — The organism enters the circulating blood and at first causes a varying febrile condition. Later the patient goes into the sleeping-sickness proper, which condition is hopeless. Diagnosis — Make stained preparations of the blood. If the organisms are few a method of con- centrating the organisms can be carried out as fol- lows : ^Lake a vena puncture and draw ofl:* about 15 cc. of blood into :> cc. of a 2.5 per cent solution of sodium citrate in N/NaCl, which will prevent it from clotting. Centrifugalize and draw off cellular elements, make smears and stain, as follows : Add acid alcohol to fix smear and remove hemoglobin al- 275 • lowino: to stand 30 minutes to 2 hours. Wash in running water for half to two hours to remove all acid. Dry in the air and stain with Romanowsky stain. A surer method is to inject rats with a small amount of blood and examine rat's blood for the parasites. Lmnhar Puncture — The organisms are present in the second stage of the disease. Draw off fluid, centrifugalize and examine sediment. Gland Puncture — Aspirate a suspected gland with a hypodormic needle. A surer method is to remove a gland and examine or inject preparations of it into rats. Mode of Infection — Through the common fly, Glossina palpalis. There are two methods of trans- mission. 1. Immediate or direct. 2. Indirect. A sexual type of development takes place Avhich requires an average of 24 days for the fly to become infective. This can be varied by change in temperature. The fly is infective as long as he lives. Trichomonas intestixalis. This organism is probably the same as Tricho- monas vaginalis. It is found in the vagina, urethra, large and small intestine, stomach and sputum. Size — 20 to 25 microns by 8 to 12 microns. I </5 1 13 ■(3 g5 C aj =5 i^T ^ ri "382 j^;^ o^ § t, 3 X ? 'S i2 =2 .2; c u >. "i^ a a, g X ._ bo— « M t- ^ o ^ JO £ —^ ® „ ij Q^ P ^ C bi" 5 276 fl- C 0^ - - fc-43 ,.5 ^i^' o •> !« t-l C I ' >-l • tJ I 1 1 1 « c-r! 07; c ;-i o tj Q .— *j t- ® a c o « ® e - ilT'S 2-% J«-?? 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