Parasitic infections of blood and tissues Flashcards Preview

Year 1 Microbiology > Parasitic infections of blood and tissues > Flashcards

Flashcards in Parasitic infections of blood and tissues Deck (28):
1

What is the pathogenesis of african sleeping sickness?

1. Flagellated protozoa develops in gut of tsetse fly 2. Chancre / hard nodule at site of bite 3. Parasite replicates in blood and lymphatics and goes to CNS

2

What is the causative agent of Chaga's disease?

Trypanosoma cruzi

3

What is the causative agent of African sleeping sickness?

Trypanosoma brucei

4

What are the symptoms of Chaga's disease?

1. Development of chagoma (Romana's sign) 2. Fever, malaise, myalgia, hepatosplenomegaly 3. Asymptomatic for life, or chronic (cardiac and GI)

5

What is the diagnosis for Chaga's disease?

1. Travel history 2. Acute - detection in peripheral blood 3. Chronic - serology

6

How is Leishmaniasis transmitted?

Bite of sand fly - parasites are regurgitated into blood stream

7

What are the reservoirs for leishmaniasis?

Dogs and rodents

8

What are the leishmaniasis spp. responsible for cutaneous presentations?

L. major, L. tropica, L. mexicana

9

What are the leishmaniasis spp. responsible for mucocutaneous presentations?

L. braziliensis

10

What are the leishmaniasis spp. responsible for visceral presentations?

L. donovani, L. infantum, L. chagasi

11

What is the initial presentation for visceral leishmaniasis?

Persistent low grade fever

12

Resolution of leishmaniasis is dependent on what type of immunity?

Cell mediated immunity (gamma interferon mediated activation of macrophages)

13

What are the main malaria-causing species of plasmodium?

P. falciparum and P. vivax

14

What is the characteristic clinical feature of malaria?

Malarial paroxysm

15

What are the durations and patterns of paroxysm for malarial species?

1. P. vivax and P. ovale - 48 hrs 2. P. malariae - 72 hrs 3. P. falciparum - 48 hrs

16

How does anemia occur in malaria?

Asexual stage of parasite destroys RBCs each time it completes a cycle of replication

17

What are the three mechanisms involved in the pathogenesis of malaria?

1. RBC lysis by mature asexual intra-erythrocytic parasites 2. Suppression of erythropoiesis by cytokines (TNFa, IL-1) 3. Destruction of RBCs by the spleen

18

Severe anemia is seen in which species of plasmodium?

P. falciparum - highest parasitemia

19

What are other symptoms / complications of malaria?

Splenomegaly, hypoglycemia, lactic acidosis, microvascular sequestration

20

Which populations are most at risk for babesiosis infection?

Elderly, asplenic, immunosuppressed

21

The Maltese Cross morphology is indicative of what disease?

Babesiosis (Babesia spp.)

22

What is the treatment for babesiosis?

Atovaquone and azithromycin (quinine / clindamycin)

23

How is babesiosis transmitted?

Bite of tick

24

What are the causative agents of filariasis?

Filarial nematodes Wuchereria bancrofti and Brugia malayi

25

What is the vector for filariasis?

Mosquito

26

How is schistosomiasis transmitted?

1. Egg get into water via urine or feces 2. Eggs hatch, infect snails, release cercariae which penetrate human skin and circulate to intestine, liver or bladder

27

What are the symptoms of S. japonicum / S. mansoni infection?

Chronic intestinal and hepatic dysfunction - portal fibrosis and hypertension

28

What are the symptoms of S. haematobium infection?

Hematuria, dysuria, urinary frequency, loss of bladder function, increased occurrence of squamous cell carcinoma of bladder