Para Samplex

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PARA FINALE II (2005)

1. An 18-year old male patient sought consult due to fever, with hepatosplenomegaly and urticarial rashes. He recalled that three weeks ago there were appearance of transient pruritus and skin rash immediately after exposure to a pond near rice fields. The following are true of this case EXCEPT: A. Infection was acquired through penetration of the parasite through the skin B. Eggs can be the diagnostics tool for identification of the parasite

C. The probably parasite needs at least two intermediate host to survive D. Cercaria is the infective state to humans 2. Mature eggs with fully embroyonated miracidium and terminal spine A. S. haematobium B. S. mansoni C. S. japonicum D. none of the above 3. Dioecius adult worms living primarily in the vesical and pelvic plexuses of the venous circulation less commonly in the portal blood stream A. S. japonicum B. S. haematobium C. S. mansoni D. A, B, C 4. Integumentary trabeculations of the male are more conspicuous and testes number 6 to 9 A. S. mansoni B. S. japonicum C. S. haematobium D. A, B, C 5. All these trematodes are leaf-like and hermaphroditic EXCEPT A. Blood flukes B. Live flukes C. Lung flukes D. Intestinal flukes 6. Which of the ff schistosomes produce an ovum with a lateral spine not readily appreciated on stool exam: A. Schistosoma japonicum B. Schistosoma hematobium C. Schistosoma mansoni D. none of these 7. Among the female Schistosomes, the one which is considered most prolific in terms of its egg-laying capacity is A. Schistosoma japonicum B. Schistosoma hematobium C. Schistosoma mansoni D. all of these 8. A 45-year old farmer diagnosed to have colonic cancer had a finding of parasite ova described as having a larva with rudimentary spine in the shell. Your most likely diagnosis of a parasitic infection is A. Ancylostomiasis B. Schistosomiasis C. Heterophyiasis D. Fascioliasis 9. The adult form of this Schistosome mainly inhabits the superior mesenteric plexuses: A. Schistosoma japonicum B. Schistosoma hematobium C. Schistosoma mansoni D. none of these 10. This female Schistosome is shorter and stouter than the male with a gynecophoral canal. A. Schistosoma japonicum B. Schistosoma hematobium C. Schistosoma mansoni D. none of these 11. Intestinal flukes EXCEPT: A. Heterophyes heterophyes B. Paragonimus westermani C. Fasciolopsis buski D. Metagonimus yokogawai 12. Flukes which needs a snail for both its 1st and 2nd intermediate hosts. A. F. buski B. P. westermani C. H. heterophyes D. E. ilocanum 13. Giant intestinal fluke A. F. buski B. F. hepatica C. P. westermani D. none 14. Human infection is acquired from the raw consumption of Pila luzonica snails A. E. ilocanum B. P. westermani C. C. sinensis D. B & C 15. In the life cycle of Echinostoma ilocanum, the required intermediate hosts are A. snail and snail C. snail and aquatic vegetation B. snail and crabs D. snail and fish 16. In the life cycle of Paragonimus westermani, the required intermediate hosts are A. snail and snail C. snail and aquatic vegetation B. snail and crabs D. snail and fish 17. Edema of the face, bloody mucoid diarrhea and intestinal obstruction are manifestations commonly observed in A. Echinostomiasis B. Fascioliasis C. Fasciolopsiasis D. Heterophyiasis 18. Halzoun is associated with which of the following trematode infections? A. Fascioliasis B. Fasciolopsiasis C. Echinostomiasis D. Heterophyiasis 19. The presence of a cephalic cone is a feature of an adult: A. Clonorchis sinensis B. Opistorchis felineus C. Fasciola hepatica D. Opistorchis viverinii

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PARA FINALE II (2005)

20. The adult fluke locks life “coffee beans”: A. Clonorchis sinensis

C. Paragonimus westermani 21. Hematuria is a prominent of infection with: A. Schistosoma mansoni C. Schistosoma haernatobium 22. The adults live in the duodenum A. Fasciola hepatica

B. Fasciola hepatica D. Schistosoma japonicum B. Schistosoma japonicum D. All of these

C. Clonorchis sinensis D. Paragonimus westermani 23. In the life cycle of Fasciola hepatica, what dev lopraental stages occur inside the snail first intermediate host? A. miracidium sporocyst-redia C. redia-cercaria-metacercaria B. sporocyst-redia-cercaria D. sporocyst-cercaria-metacercaria 24. Mestacercaria encysted in flesh of freshwater fist is infective to definitive host A. Fasciola hepatica C. Clonorchis sinensis B. Fasciolopsis buski D. Paragonimus westermani 25. Metacercaria encysted on water chestnuts is infective to definitive host A. Fasciola hepatica C. Paragonimus westermani B. Clonorchis sinensis D. Fasciolopsis buski 26. Developmental state of Fascioloa hepatica infective to the 1 st intermediate host A. Egg B. miracidium C. cercaria D. metacercaria 27. A patient from sheep and cattle raising country developed enlarged and tender liver, jaundice, digestive disturbance and diarrhea. He has history of eating watercress salads before the onset of symptoms. What is the most likely diagnosis? A. Fasciola hepatica C. Clonorchis sinensis B. Opistorchis felineus D. Opistorchis viverrini 28. This parasite is commonly known as the sheep liver fluke: A. Echinostoma ilocarium B. Clonorchis sinensis C. Fasciola hepatica D. Fasciolopsis buski 29. This parasite is commonly known as the Chinese liver fluke: A. Echinostoma ilocarium B. Clonorchis sinensis C. Fasciola hepatica D. Fasciolopsis buski 30. Lancet shaped and almost transparent fluke A. Fasciola B. Paragonimus C. Echinostoma D. Clonorchis 31. Ova has a flattened operculum and thickened abopercular end. A. F. buski B. P. westermani C. H. heterophyes D. M. yokogawai 32. Human infection is acquired by eating uncooked freshwater crabs. A. F. buski B. P. westermani C. H. heterophyes D. E. ilocanum 33. Edemic hemoprysis A. H. heterophyes B. P. westermani C. F. buski D. A, B, C

B. Fasciolopsis buski

34. A 50-year old patient from Bicol came in because of an on and off fever and chronic productive cough. His chest x-ray revealed a “coin-lesion” at the mid portion of the right lung field with blunting of the right costo-phrenic angle. A sputum examination revealed golden ova with operculum. Your diagnosis of this case is A. Schistosomiasis B. Loaffler’s pneumonia C. Paragonimiasis D. Pneumocystosis 35. Metacercaria encysted in flesh of various crustaceans (crayfish, crabs) is infective to definitive host A. Fascioloa hepatica C. Clonorchis sinensis B. Fasciolopsis buski D. Paragonimus westermani 36. Longest tapeworm of man A. T. solium B. T. saginata C. D. latum D. E. granulosus 37. Presence of 15-30 uterine branches in gravid segments: A. T. solium B. T. saginata C. H. nana D. E. granulosus 38. Larvae of D. latum infective to man: A. procercoid larva B. plerocercoid larva C. cysticercoid larva D. A & C 39. Scolex is spatulate with two sucking grooves: A. D. latum B. E. granulosus C. H. nana D. H. diminuta 40. Region of growth of cestodes: A. scolex B. neck C. strobila D. none

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PARA FINALE II (2005)

41. May cause cerebral cysticercosis in man: A. T. solium B. T. saginata C. H. nana D. E. granulosus 42. Characteristics eggs show an inner envelope with polar thickening and filaments. This is true of: A. Hymenolepis nana C. Hymenolepis diminuta C. both D. neither 43. Drug of choice in the treatment of Taeniasis: A. Praziquantel B. Metronidazole C. Mebendazole D. Thiabendazole 44. Egg is subspherical whose inner membrane has two polar thickenings but no polar filaments: A. H. nana B. H. diminuta C. D. caninum D. E. granulosus 45. Useful in the diagnosis of T. solium A. Proglottids B. eggs C. both D. neither 46 Smallest of all tapeworms with only three proglottids A. Echinococcus B. H. nana C. H. diminuta D. none 47. The hydatid sand in Echinococcus infection are:

A. free protoscoleces tying inside the hydatid B. necrotic debris resulting from degeneration of the initial larval stages C. food for nutrition of the worm D. freely floating small ova 48. The known habitat of Taenia saginata is: A. small intestine of cattle C. small intestine of man B. small intestine of swine D. muscle of the hogs 49. The adult tapeworm is characterized by a scolex having four suckers and a rostellum with hooks: A. Taenia solium B. Taenia saginata C. both D. neither 50. The adult tapeworm is characterized by a scolex having four suckers and a rostellum without hooks: A. Taenia solium B. Taenia saginata C. both D. neither 51. The ova of this tapeworm is characterized by a radially striated embryophore: A. Taenia solium B. Taenia saginata C. both D. neither 52. Cysticercosis in man may occur as a result of ingestion of the parasite’s A. ova B. oncosphere C. procercoid larva D. pterocercoid larva 53. The drug of choice in the treatment of cyticercosis in man is: A. albendazole B. bithionol C. praziquantel D. mebendazole 54. The scolex of this tapeworm is elongated without any suckers but contain a ventral and dorsal groove: A. Echinococcus B. Hymenolepis C. Diphyllobothrium D. Dipylidium 55. Each proglottid of this tapeworm contain both female and male reproductive organ … which the eggs are discharged A. Echinococcus B. Hymenolepis C. Diphyllobothrium D. Dipylidium 56. The eggs of this tapeworm are operculated with a small knob at the abopercular end A. Echinococcus B. Hymenolepis C. Diphyllobothrium D. Dipylidium 57. This is also called the Jewish housewives’ disease A. Echinococcosis B. Hymenolepsiasis C. Diphyllobothriasis D. none of the choices 58. This is most closely associated with associated with Vitamin B12 deficiency A. Echinococcosis B. Hymenolepsiasis C. Diphyllobothriasis D. none of the choices 59. Proglottids of this tapeworm are often passed in chains: A. Echinococcus B. Hymenolepis C. Diphyllobothrium D. Dipylidium 60. Muscle pain and weakness are manifestations of A. Taeniasis saginata B. Taeniasis solium C. cysticercosis D. all of the above 61. This tapeworm has thin-walled ova: A. Echinococcus B. Hymenolepis C. Diphyllobothrium D. Taenia 62. The study of a parasite’s life cycle is useful to: A. recognize the diagnostic stage C. plan a control programme B. recognize the infective stage D. all of the above 63. Nematodes are also called: A. tapeworms B. roundworms C. flukes D. flatworms 64. Trematodes are also called: A. tapeworms B. roundworms C. flukes D. flatworms

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PARA FINALE II (2005)

65. Cestodes are also called:

A. tapeworms

B. roundworms 66. Region of growth of cestodes: A. scolex B. neck 67. Major features of the Cestoda are, except: A. Platyhelnunths

C. flukes

D. flatworms

C. strobila

D. none

B. Adults are all endoparasites C. No guy at adult stage of the life cycle D. They have a characteristic larva called hexacanth. This is a little larva with six hooks, arranged in three pairs 68. The term used to describe infection by the plerocercoid larva of a pseudophyllidean tapeworm: A. Spirometrosis B. Sparganosis C. plerocercoidosis D. none 69. May cause cysticercosis in humans: A. Taenia saginata B. Taenia solium C. both D. neither 70. Commonly known as the broad fish tapeworm: A. Taenia saginata B. Taenia solium C. Diphyllobothrium latum D. Dipylidium caninum 71. A 25 yr. old Japanese male went to the ER because of a subcutaneous swelling on both lower extremities. This is accompanied by allergic manifestations and occasional abdominal pain. Small hemorrhages and edema were also observed around the subcutaneous lesions. Biopsy was done on the lesion and revealed parasite eggs characterized by sculptured shell with transparent knob at one end. What is the most likely parasite involved in this case? A. Griasthostoma spinegerum B. Ascaris C. D. medinesis D. T. cruzi 72. Rat lung worm is the common name of: A. Gnathostoma spinigerum B. Trichinella spiralis C. Angiostrongylus cantonensis D. Toxocari canis 73. … infection A. E. vermicularis B. A. lumbricoides C. T. trichiura D. T. canis 74. Pruritus ani is a prominent manifestation of infection with this parasite A. E. vermicularis B. A. lumbricoides C. T. trichiura D. T. canis 75. 76. The female worms discharge larvae into water through an ulcerated area in the skin: A. Gnathostoma spinigerum B. Angiostrongylus C. Onchocerca volvulus D. Dracunculus medinensis 77. Humans are infected by ingestion of snails infected with the 3 rd stage larvae: A. Gnathostoma spinigerum B. Angiostrongylus C. Onchocerca volvulus D. Dracunculus medinensis 78. Humans are infected by drinking water contaminated with Cyclops harboring the 3 rd stage larvae: A. Gnathostoma spinigerum B. Angiostrongylus C. Onchocerca volvulus D. Dracunculus medinensis 79. The adult worms live in the pulmonary arteries of the rat A. Gnathostoma spinigerum B. Angiostrongylus C. Onchocerca volvulus D. Dracunculus medinensis 80. Infection with these worms produce disease known as eosinophilic meningitis: A. Gnathostoma spinigerum B. Angiostrongylus C. Onchocerca volvulus D. Dracunculus medinensis 81. The adule worms have a distinct head bulb covered by a row of hooks A. Gnathostoma spinigerum B. Angiostrongylus C. Onchocerca volvulus D. Dracunculus medinensis 82. The ova of this parasite are ovoid with a single polar thickening A. Gnathostoma spinigerum B. Angiostrongylus C. Onchocerca volvulus D. Dracunculus medinensis 83. The 2nd intermediate host of Gnathostoma: A. Cyclops spp. B. frogs C. crabs D. snail 84. This parasite causes the so called “migrating edema” A. Gnathostoma spinigerum B. Angiostrongylus C. Onchocerca volvulus D. Dracunculus medinensis

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PARA FINALE II (2005)

85. Patients infected with this parasite show symptoms like neck rigidity & headache A. Gnathostoma spinigerum B. Angiostrongylus C. Onchocerca volvulus D. Dracunculus medinensis 86. The anterior half of this parasite is covered with broad leaf-like spines which are tridented A. Gnathostoma spinigerum B. Angiostrongylus C. Onchocerca volvulus D. Dracunculus medinensis 87. Loeffler’s syndrome is due to what stage of the causative parasite? A. embryonated egg B. fertilized egg C. larvae D. adults 88. The female parasite emerges from an ulcerated to discharge larvae A. Gnathostoma spinigerum B. Angiostrongylus C. Onchocerca volvulus D. Dracunculus medinensis 89. CSF examination shows low sugar, high protein, and high eosinophilia A. Gnathostoma spinigerum B. Angiostrongylus C. Onchocerca volvulus D. Dracunculus medinensis 90. This parasite has a reputation for being erratic: A. Ascaris sp C. Toxocari sp B. Enterobius sp D. Anisukis sp 91. The most common cause of lymphatic filariasis is A. Wucheririae banerafti C. Loa loa B. Brusia malayi D. Dirofilaria immitis 92. A 6 year old male from X was admitted to the local government hospital Y because of severe dehydration. He has history of passing unsegmented, creamy white adult worms through the arias. This patient is most likely having a A. nematode infection C. trematode infection B. cestode infection D. protozoan infection 93. What stage in the life cycle of a nematode parasite is most likely to produce a pulmonary problem? A. larva B. ova C. adult D. larva and adult 94. Parasite/s that leave the host’s body via the sputum: A. Paragonimus westermani C. Trichomonas vaginalis B. Ascaris lumbricoides D. A & B 95. Portal of entry is thru inhalation of airborne eggs into posterior pharynx: A. Ascaris lumbricoides C. Shistosoma japonicum B. Enterobius vermicularis D. A, B, C 96. Blood-sucking insects causing malaria belong to the Genus: A. Anopheles B. Culex C. Mansonia D. Simulium 97. Cysticercus cellulosae is the immature infective stage of this parasite and acts as source of infection: A. Taenia saginata B. Taenia solium C. Diphyllobothrium latum D. Hymenolepis nana 98. The trophozoite is pyriform or teardrop shaped, pointed posteriorly with paired nuclei, one on each side of mixlline; A. Trichomonas tenax C. Trichomonas hominis B. Giardia lamblia D. Trichomonas vaginalis 99. Clinically undergo malabsorption syndrome and gastrointestinal symptoms: A. Giardia lamblia C. Trichomonas hominis B. Trichomonas vaginalis D. Trichomonas tenax 100. A larger organism that provides physical protection and nourishment is termed: A. Host B. Parasite C. Parasitism D. Spurious parasite 101. The normal habitat of Ascaris lumbricoides is the: A. small intestine B. cecum C. lungs D. appendix 102. The infective stage of Ascaris lumbricoides is the: A. unfertilized egg B. fertilized egg C. embryonated egg D. larvae 103. This roundworm causes visceral larva migrans: A. A. lumbricoides B. Toxocara C. Anisakis D. Trichuris trichiura 104. This roundworm causes Loeffler’s Syndrome: A. A. lumbricoides B. Toxocara C. Anisakis D. Trichuris trichiura 105. Adult male and female worms live in clusters with their anterior end embedded in a crater like tumor of the gastric mucosa A. Toxocara sp. B. Anisakis sp C. Ascaris sp. D. Enterobius sp

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PARA FINALE II (2005)

106. An immuncompromised patient diagnosed with Acute leukemia has gross hermaturia with no other accompanying manifestations. His urinalysis revealed red cells and a larval stage of the parasite. Patient claimed that he had bouts of diarrhea during the last two weeks. Your most likely diagnosis of this case is: A. Ancylostomiasis B. Strongyloidiasis C. Necatoriasis D. All of these 107. The stage of the parasite in number 106 infective to man in this case is A. Rhabditiform larva C. third stage filiform larva B. Encysted larva D. filariform larva 108. A 36-year old male coffee farmer from Batangas consulted in a government hospital outpatient department due to mild diarrhea associated with vague abdominal pain of 6 days duration. There was also associated generalized body weakness and poor appetite. A history of dry cough and soreness of the throat a few days before start of the diarrhea, was elicited. Physical examination revealed urticaria on both feet especially the sole. Examination of blood revealed slightly decreased hemoglobin and hematocrit and mild eosinophilia. Peripheral smear showed normocytic red blood cells with mild hypochromia. Stool examination showed thin shelled ova in early cleavage stage. X-ray examination revealed clear lungs. 109. The most likely diagnosis in this case is: A. Scabies B. Filariasis C. Hookworm Disease D. Onchocerciasis 110. The infective stage of this parasite is the: A. Egg B. rhabditiform larva C. filariform larva D. adult 111. Appropriate management of the anemia in this case is by: A. transfusion of packed red blood cells C. iron-rich diet B. ferrous sulfate tablets D. only B & C 112. Smallest nematode worm of humans A. Trichuris trichura B. Capillaria philipinensis C. Trichinella spiralis D. Ascaris lumbricoides 113. Adult worms have a slender-filiform anterior end arid a stouter posterior portion. The appearance of which resembles a “whip” A. Trichuris trichura B. Capillaria philipinensis C. Trichinella spiralis D. Ascaris lumbricoides 114. Female adult worms larger than the male A. Trichuris trichiura B. Capillaria philipinensis C. Trichinella spiralis D. All of the above 115. Clinical picture of infection is intestinal malabsorption with symptoms of chronic diarrhea A. T. trichiura B. C. philippinensis C. T. spiralis D. A & C 116. Severe infection leads to rectal prolapse A. T. spiralis B. C. philippinensis C. T. trichiura D. A & B 117. The drug of choice in the treatment of falciparum malaria is A. chloroquine only B. chloroquine and primaquine C. primaquine only D. chloroquine, primaquine, and quinine 118. Which of the Ff. sexual stages of Plasmodium falciparum is infective to the intermediate host? A. sporozoite B. trophozoite C. merezoite D. gametocyte 119. Which of the following is/are associated with relapse? A. P. vivax and P. malariae B. P. ovale and P. vivax C. P. ovale D. P. falciparum and P. malariae 120. Recurrence of paroxysms after the initial attack in malariae malaria is called: A. recrudescence B. relapse C. reinfection D. all of these 121. A finding of more than 40% Heinz bodies in the peripheral blood smear means A. the patient has a high risk of developing malarial infection B. is concurrently positive with plasmodium infection C. that the patient has G6PD deficiency, and therefore prone to develop hemolysis with some antimalarial drugs

D. All of these 122. Renewed manifestation of infection due to the invasion of blood by hypnozoites (dormant form of merozite). A. Paroxysms B. Recrudescence C. Relapse D. Parasitaemia 123. In the life cycle of Plasmodium, exflaggelation takes place in the A. liver phase C. erythrocytic phase B. sporogonic phase D. schizogonic phase

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PARA FINALE II (2005)

124. Which of the following is associated with nephritic syndrome? A. benign tertian malaria C. quartan malaria B. malignant tertian malaria D. subtertian malaria 125. These political provinces in the Philippines are free of malaria, EXCEPT: A. Cebu B. Leyte C. Bohol 126. Liver enlargement in falciparum infection is due to

D. Zamboanga

A. ballooning degeneration of hepatocytes B. fatty change C. hypertrophy and hyperplasia of tissue macrophages D. periportal fibrosis 127. Protozoan that may infect the common bile duct and gallbladder: A. Giardia lamblia C. Trichomonas vaginalis B. Entamoeba histolytica D. B & C 128. Causative parasite of Traveller’s diarrhea A. Chilomastix mesenili C. Giardia lamblia B. Trichomonas tenax D. Dientamoeba fragilis 129. Onset of vulvar pruritus, vaginal pruritus with vaginal discharge usually acute and occurs with or after menstruation. A. Trichomonas vaginalis C. Trichomonas hominis B. Trichomonas tenax D. A, B, C 130. Exact method of transmission is unknown, exposure result from droplet spray from mouth, kissing or use of contaminated dishes and drinking glasses. A. Chilomastix mesenili C. Trichomonas hominis B. Trichomonas tenax D. Trichomonas vaginalis 131. Diagnosis is by fecalysis and enterotest A. Amoebiasis B. Giardiasis C. Trichomoniasis D. A & C 132. The trophozoite is pyriform or teardrop shaped, pointed posteriorly with paired nuclei, one on each side of midline: A. Trichomonas tenax C. Trichomonas hominis B. Giardia lamblia D. Trichomonas vaginalis 133. Human infection may come either from consumption or handling of infected men or from contact with feces in soil A. Toxoplasma B. sarcocystis C. Cryptosporidium D. B &C 134. Seatorrheic diarrhea A. E. histolytica B. G. lamblia C. both D. neither 135. Pathogenic state of Entamoeba histolytica A. trophozoite B. cyst C. both D. neither 136. Pathogenic amoeba A. Entamoeba histolytica C. Endolimax nana B. Entamoeba coli D. Iodamoeba buetschlii 137. Spherical cyst with 1 to 8 nuclei and whiskbroom chromatoidal body A. Entamoeba coli C. Endolimax nana B. Entamoeba histolytica D. Iodamoeba buetschlii 138. Spherical cyst with 1 to 4 nuclei and bull’s eye appearance of karyosome A. Entamoeba coli C. Endolimax nana B. Entamoeba histolytica D. Iodamoeba buetschlii 139. Cyst is spherical or oval, cytoplasm appears clean-looking or with ground-glass appearance A. Entamoeba coli C. Endolimax nana B. Entamoeba histolytica D. Iodamoeba buetschlii 140. High incidence of extraintestinal amoebic infection occurs and develops in A. right lobe of the liver C. lungs B. left lobe of the liver D. brain 141. Entamoeba histolytica contaminating food or drink is in the form of: A. trophozoite B. cyst C. both 142. No cystic stage A. Dientamoeba fragilis C. Entamoeba coli B. Entamoeba histolytica D. Endolimax nana 143. An important reservoir of Balatidium coli is: A. cattle B. fish C. pig

D. neither

D. dog

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PARA FINALE II (2005)

144. A 12 year old male is brought to the ER because of changes in sensorium. Few hours ago, patient complained of severe headache which was followed by fever, headache and vomiting. The amoeba most probably causing this presentation is: A. Acanthamoeba B. Naegleria C. Balantidium D. None 145. The largest protozoan known to infect man is the: A. Entamoeba coli C. Balantidium coli B. Naegleria fowleri D. Entamoeba histolytica 146. Blood transfusion for the management of severe anemia and hemolysis in complicated falciparum malaria would ideally be in the form of: A. whole blood C. packed red blood cells B. fresh frozen plasma D. plasma expanders 147. Irregular and crenated red blood cells are most associated with this specie: A. Plasmodium ovale C. Plasmodium falciparum B. Plasmodium vivax D. Plasmodium malariae 148. The presence of a parasite in or on the tissues of a host. Such colonization may or may not have a deleterious effect on the host. This is called a/an: A. disease B. epidemic C. pandemic D. any of the above 149. An infection which has always existed in a region. A. endemic B. epidemic C. pandemic D. all of the above 150. The time between the entrance of a parasite into a host and the beginning of a disease. A. virulence B. incubation C. patent period D. none