Parasitic Infections in Blood and Lymph Flashcards
What are the blood and lymph infective protozoans?
Plasmodium sp.
Babesia sp.
Trypanosoma sp.
What are the blood and lymph filarial nematodes?
Wuchereria bancrofti
Brugia malayai
Onchocerca
Which trematode infects the blood?
Schistosomes
What cause malaria?
Plasmodium
Where does plasmodium live in the host?
Inracellular in hepatocytes and RBCs
Which species of plasmodium effect humans?
P. vivax
P. ovale
P. malariae
P, falciparum
What is the life cycle pattern of plasmodium?
A mosquito uptake a exflaggellated gamete which grows into a zygote, oocyst and then sporozoite
A female mosquito goes to drink blood from a human releasing the sporozite into the blood where it becomes a liver schizont
It will cycle between schizont and trophocyte by way of merozoites
It will become a gametocyte from a merozoite that does’t hate you and a mosquito drink it up
What is the incubation period for malaria?
1 to 2 weeks
What are the clinical signs of malaria?
Flu-like illness, headache, anorexia
Classic sighs of cycled fever, chills and rigor
Why is fever caused due to hemolytic anemia in malaria?
RBCs explode so hemoglobin and debris release the parasite antigen (GPI) leading to host secretion of TNF and IL-1
What are the fever cycles for the different types of plasmodiums?
Vivax and ovale: 48 hours
Malariae: 72 hours
Falciparum: at random
Which plasmodium can cause CNS or renal involvement?
Falciparum
Which plasmodium enjoy killing baby RBCs to breed their nastiness?
Vivax and ovale
Which plasmodium replicates in mature RBCs?
Malariae
Which plasmodium can form hypnozoites in the liver?
Vivax and ovale
What drug is needed if hypnozoites are present?
Primaquine
Which is the most severe plasmodium infection? Why?
Falciparum
Many strain are resistant to chloroquine
Replicates in erthrocytes at any age
More parasite replication
What is the parasite antigen of P. falciparum expressed on infected RBCs and what does it bind to?
pfEMP-1
ICAM-1
Due to the antigen presentation in P.falciparum, what happens when the RBCs block small vessels?
Block blood supply to organs leading to organ damage
What are the severe clinical manifestations of P.falciparum?
Cerebral malaria
Blackwater fever (renal damage)
Fetal and mother death in pregnancy
What is used for indication of malaria and what can you see?
Giemsa stained blood smears
Ring form, gametocytes, trophozoites, schizonts
If you happen across a chloroquine-resistant form of P. falciparum, what can you use instead?
Mefloquine
Quinine+doxycycline
Quinine+clindamycin
What drugs would you use for P. falciparum and P. malariae?
Chloroquine
What drug would you use for P. vivax and P. ovale?
Chloroquine+primaquine
How can malaria be prevented?
Mosquito control
Avoid mosquito bites
Chemoprophylaxis
In chemoprophylaxis use, what drugs should be taken to avoid malaria?
The same as the drug taken if you get malaria
P falciparium: same as previously mentioned plus atovaquone+proguanil = Malarone
What type of parasite causes babesiosis?
Babesia microti - protozoan
What is the vector for Babesia microti?
Ticks (Ixodes dammini)
What is the reservoir for babesia microti?
Mice
Immature ticks feed on mice, adults feed on deer
Nymphs and adults will also feed on humans
What is the pathogenesis of babesiosis?
Bite of infected tick, babesia replicates in erythrocytes, RBC lysis to release merozoites, 1-4 week incubation, fever chills head ache fatigue weakness, hemolytic anemia or renal failure
How is babesiosis diagnosed?
Demonstration of parasite in thick and thin blood smears
What is the treatment for babesiosis?
Clindamycin plus quinine
Atovaquone plus azithromycin
What is the cause of Chaga’s disease?
Trypanosoma cruzi (prorozoan)
What is the vector and reservoir for T. cruzi?
Triatomid bugs
Armadillos, rodents, dogs
What are the acute clinical manifestations of Chaga’s disease
Generally asymptomatic
Fever, anorexia, lymphadenopathy, mild hepatosplenomegaly, myocarditis
Chagoma - nodular lesion at inoculation site
Romana’s sign - chagoma near eye (unilateral periocular swelling)
What are the chronic manifestations of Chaga’s disease?
Amastigotes replicate in various cell types
Megaesohagus or megacolon
Cardiomyopathy
What is antigenic mimicry?
The parasite mimics the antigens of the heart muscle causing the immune system to attack to parasite but become confused and being attacking the heart as well
How is Chaga’s disease diagnosed?
Finding trypomastigotes in blood or amastagotes in biopsies of lymph nodes, spleen, liver or bone marrow
What is the treatment for Chaga’s disease?
Chronic not reversible
Some drugs for acute
What causes African sleeping sickness?
Trypanocomes brucei
What is the vector and reservoir of T. brucei?
Tsetse fly Wild ungulates (antelopes)
What are the two species of T. brucei in Africa?
T. brucei gambiense (West and Central)
T. brucei rhodesiens (East and South)
What is the the pathogenesis of sleeping sickness?
Bit of Tsetse fly, T. brucei replicates in blood and lymph, fever-lymphpadenopathy-pruritus, enters CNS after weeks/month, alter mental and sensory status, difficultly walk and talk, coma and death
How is T. brucei diagnosed?
Detection of trypomastigotes in blood, CSF and lymph films
How is T. brucei treated?
Suramin for blood and lymph phases
Malarsoprol for CNS
What are the different species of Schistosoma (blood flukes?
S. haematobium
S. manosi
S. japonicum
What is the life cycle of a Schistosoma?
Eggs hatch in the water as miracidum enter cell which develops into a cercaria released from the snail and burrow through skin which then develops into an adult and lays eggs in the blood and eventually are released in urine or feces
Where is S. haematobium found, where are adults found and where are eggs expelled from?
Africa and Middle East
Bladder vessels
Urine
Where are the adults of S. mansoni and S. japonicum found as adults and where are the eggs expelled from?
Venous plexus of intestines
Stool
What are the clinical manifestations of schitosomiasis?
Allergic dermatitis associated with cercarial penetration of skin Katayama fever (immune rxn to egg production) Granulomatoud lesions interfere with organ function
What is the treatment for Schitosomiasis?
Praziquantel
How can Schitosomiasis be controlled?
Education, improved snaitation, bio-control agents, molluscicides, drain marshes
What are the filariasis parasites?
Wuchereria bancrifti
Brugia malayi
Onchocerca volvulus
Loa loa
Which Filariasis causes elephantiasis?
Wuchereria bancrifti
Brugia malayi
What does Onchocercosis cause and what is the vector?
River blindness due to microfilariae in eye Black fly (Simulium)
What are the clinical manifestations of Onchocercosis?
Due to inflammatory response to microfilariae
Nodules on skin, depigmentation, thickening, itching
How do you diagnose Onchocercosis?
Demonstration of microfilariae in skin snip prep
What is the treatment of Onchocercosis?
Surgical removal of nodules containing adult worms
Ivermectin
What can be used for prophylaxis against Onchocercosis?
Ivermectin and diethylacarbanizine
What is Loiasis (loa loa) transmitted by?
Mango flies or deer flies (chrysops)
What is the pattern of movement of the Loa loa?
Adult worms live in connective tissue under the skin and between facial layer over somatic muscle
Thousands of microfilariae produced daily
Adult migrate frequently and can pass across the eye
