Flashcards in Parasitic infections of blood and tissues Deck (28):
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
What is the causative agent of Chaga's disease?
What is the causative agent of African sleeping sickness?
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)
What is the diagnosis for Chaga's disease?
1. Travel history 2. Acute - detection in peripheral blood 3. Chronic - serology
How is Leishmaniasis transmitted?
Bite of sand fly - parasites are regurgitated into blood stream
What are the reservoirs for leishmaniasis?
Dogs and rodents
What are the leishmaniasis spp. responsible for cutaneous presentations?
L. major, L. tropica, L. mexicana
What are the leishmaniasis spp. responsible for mucocutaneous presentations?
What are the leishmaniasis spp. responsible for visceral presentations?
L. donovani, L. infantum, L. chagasi
What is the initial presentation for visceral leishmaniasis?
Persistent low grade fever
Resolution of leishmaniasis is dependent on what type of immunity?
Cell mediated immunity (gamma interferon mediated activation of macrophages)
What are the main malaria-causing species of plasmodium?
P. falciparum and P. vivax
What is the characteristic clinical feature of malaria?
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
How does anemia occur in malaria?
Asexual stage of parasite destroys RBCs each time it completes a cycle of replication
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
Severe anemia is seen in which species of plasmodium?
P. falciparum - highest parasitemia
What are other symptoms / complications of malaria?
Splenomegaly, hypoglycemia, lactic acidosis, microvascular sequestration
Which populations are most at risk for babesiosis infection?
Elderly, asplenic, immunosuppressed
The Maltese Cross morphology is indicative of what disease?
Babesiosis (Babesia spp.)
What is the treatment for babesiosis?
Atovaquone and azithromycin (quinine / clindamycin)
How is babesiosis transmitted?
Bite of tick
What are the causative agents of filariasis?
Filarial nematodes Wuchereria bancrofti and Brugia malayi
What is the vector for filariasis?
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
What are the symptoms of S. japonicum / S. mansoni infection?
Chronic intestinal and hepatic dysfunction - portal fibrosis and hypertension