Block 10 Blood Tissu Protozo Filar Worms MCQ's
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- 1.A 35-year-old English businessman was admitted to the hospital for an unexplained fever. He presented with abdominal pain, sweating, rigors and vomiting. He was jaundiced and febrile. Over the following 24 hours, he became incoherent, disoriented, stuporose and finally comatose. He had reportedly been on vacation in India. A blood smear showed intraerythrocytic organisms. Which of the following is the most probable diagnosis?
- A.
Amoebiasis
- B.
Onchocercaisis
- C.
Trypanosomiasis
- D.
Malaria
- E.
Hydatid disease
- 2.The protozoa are unicellular organisms, unlike the helminthes, that are multicellular. Which of the following killing mechanisms might be effective for protozoa but not for helminthes?
- A.
IgG facilitated killing by macrophages
- B.
Antibody dependent cellular cytotoxicity
- C.
Parasite immobilization by mucus from hyperactive goblet cells
- D.
Destruction by eosinophilic granules
- E.
IgE mediated killing
- 3.A 50-year-old biochemist was admitted to the hospital for persistent fever. He presented with abdominal pain, sweating, rigors and vomiting and was jaundiced and febrile. He had reportedly just returned from a vacation in Minnesota where he did a lot of hiking and camping. A blood smear showed intraerythrocytic organisms with peculiar tetrad forms. Which of the following would be the most probable diagnosis?
- A.
Loaiasis
- B.
Babesiosis
- C.
Trypanosomiasis
- D.
Malaria
- E.
Hydatid disease
- 4.Trypanosoma cruzi initially penetrates through the mucous membranes on the skin and then multiplies in a lesion known as a chagoma. In the chronic stage of the disease, the ma in lesions are often observed in the
- A.
Spleen and pancreas
- B.
Heart and digestive tract
- C.
Liver and spleen
- D.
Digestive tract and respiratory tract
- E.
Heart and liver
- 5.A woman, recently returned from Africa, complains of having paroxysmal attacks of chills, fever, and sweating ; these attacks last a day or two at a time and recur every 36 to 48 h. Examination of a stained blood specimen reveals ringlike and crescent-like forms within red blood cells. The infecting organism most likely is
- A.
Plasmodium falciparum
- B.
Plasmodium vivax
- C.
Trypanosoma gambiense
- D.
Wuchereria bancrofti
- E.
Trypanosoma rhodesiense
- 6.Amoebae that are parasitic in humans are found in the oral cavity and the intestinal tract. Which one of the following statements best describes these intestinal amebae?
- A.
They are usually nonpathogenic
- B.
They can cause peritonitis and liver abscesses
- C.
They are usually transmitted as trophozoites
- D.
They occur most abundantly in the duodenum
- E.
Infection with Entamoeba histolytica is limited to the intestinal tract
- 7.A butcher, who is fond of eating raw hamburger, develops chorioretinitis; a SabinFeldman dye test is positive. This patient is most likely infected with
- A.
Trichinosis
- B.
Schistosomiasis
- C.
Toxoplasmosis
- D.
Visceral larva migrans
- E.
Giardiasis
- 8.A protozoan with characteristic jerky motility is most commonly observed in
- A.
Vaginal secretions
- B.
Duodenal contents
- C.
Blood
- D.
Biopsied muscle
- E.
Sputum
- 9.A helminth that is naturally transmitted by ingestion of pork, bear, or walrus meat could be detected in
- A.
Vaginal secretions
- B.
Duodenal contents
- C.
Blood
- D.
Biopsied muscle
- E.
Sputum
- 10.A 35-year-old petroleum engineer went to work in Ecuador for a year. His work required him to eat and drink local food and water. Six months after arriving, he experienced a bout of dysentery, which resolved slowly while he took antibiotics. A month later, he noticed fever, tiredness, and pain in the right upper quadrant. A liver scan showed an abscess that measured 5X3 cm and was associated with elevated blood levels of liver enzymes. How did this disease develop?
- A.
Motile trophozoites from the colon invaded the liver
- B.
Parasitic cysts from the small intestine invaded the liver
- C.
Parasitic eggstraveled in intestinal veins to the liver
- D.
Bacteria from ulcers in the colon migrated to the liver
- E.
A hepatitis virus infected the liver to cause an abscess
- 11.A 44-year-old Brazilian man was admitted as an emergency while visiting relatives in England. His symptoms began 4 days after his arrival and he deteriorated steadily over the following ten days, with vague abdominal pain, sweating, rigors and vomiting. On evaluation, he was jaundiced, had a temperature of 39.6C, BP of 90/70, Hb of 10.2, WBC of 5.5 and a blood smear showed marked polychromasia and heavy infestation with intraerythrocytic parasites. He was started on quinine i.v, but his condition rapidly worsened over the following 24h and he became comatose and could not be resuscitated. Which one of the following was the most probable immediate cause of death?
- A.
Acute quinine toxicity
- B.
Hepatorenal syndrome
- C.
Cerebral malaria
- D.
Acute myocardial infarction
- E.
Sickle cell crisis
- 12.The World Health Organization is encouraging efforts to develop a vaccine against malaria. If the objective is to make a vaccine that can prevent disease in a person who is at risk of being bitten by an infected mosquito, what stage of the parasite's life cycle must the vaccine protect against?
- A.
Gametocyte
- B.
Merozoite
- C.
Hypnozoite
- D.
Sporozoite
- E.
Trophozoite
- 13.When a mosquito bites a victim and infects them with malaria, wh ich stage of the parasite enters the host?
- A.
Merozoite
- B.
Sporozoite
- C.
Schizont
- D.
Gametocyte
- E.
Trophozoite
- 14.You are asked to participate in trial of a new anti-malarial vaccine. The vaccine targets the immune system against the sporozoite stage of Plasmodium falciparum. Why are you concerned about the efficacy of such a vaccine?
- A.
The sporozoite stage is injected by the mosquito but quickly reaches the liver.
- B.
The sporozoite stage only exists in the liver where it is relatively protected from immune attack.
- 15.A vaccine that is intended to specifically prevent the infection of human erythrocytes by malaria parasite must be directed against what stage of the organism's life cycle?
- A.
Merozoite
- B.
Gametocyte
- C.
Sporozoite
- D.
Hypnozoite
- E.
Trophozoite
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