Blood-borne Parasitic Diseases Flashcards
1
Q
Malaria vector
A
Anopheles mosquito
2
Q
Malaria species
A
Plasmodium vivax P. falciparum P. malariae P. ovale P. knowlesi
3
Q
Malaria life cycle
A
- SPOROZOITES from mosquito saliva
- SCHIZOGONY cycle begins in liver
- MEROZOITES released from the liver
- Merozoites become uninucleate RING TROPHOZOITE
- Trophozoites age and can develop into AMOEBOID trophozoites or become MULTINUCLEATED SCHIZONT
- Erythrocytic schizonts can produce erythrocytic MEROZOITES
- RBC ruptures and they invade new cells
- Schizogony begins again or GAMETOGONY is initiated
- Mosquito feeds and takes in GAMETOCYTES that lead to sexual reproduction in the mosquito
Cycle starts over in new host
4
Q
Motile form of plasmodium
A
Sporozoites
5
Q
Cycle that takes place in the liver
A
Schizogony
6
Q
Released from the liver
A
Merozoites
7
Q
Cycle that takes place in the RBC
A
Erythrocytic cycle
8
Q
Differentiation in RBC to…
A
Ring trophozoite
9
Q
Uninucleated plasmodium in the RBC
A
Ring trophozoite
10
Q
Mature ring trophozoite
A
Amoeboid trophozoite
11
Q
Multinucleated trophozoite
A
Schizont
12
Q
Erythrocytic schizonts can produce…
A
Erythrocytic merozoites OR
Gametocytes
13
Q
Sexual cycle of plasmodium
A
Gametogony
14
Q
Sexual form of plasmodium
A
Gametocytes (male or female)
15
Q
Plasmodium that do not rupture erythrocyte
A
Gametocytes
16
Q
Pathogenicity of Malaria
A
- Consumes hemoglobin & destroys RBCs
- Fever and chills from PYROGENIC waste
- TNF intensifies symptoms
17
Q
Other signs of Malaria
A
Anemia
Hypotension
GI, HA, myalgia
18
Q
Host resistance to malaria
A
- Sickle cell = FALCIPARUM
- Duffy gene off (black people) = VIVAX
19
Q
Malaria reservoirs
A
Humans
Simians
20
Q
Infects YOUNG erythrocytes
A
P. pivax
21
Q
P. vivax key points
A
- Seldom fatal
- Young erythrocytes
- Caribbean, Latin America
- Primates are NOT reservoirs
- Sickle cell affords natural protection
22
Q
Liver hypnozoites
A
Dormant (3-5 years) form of VIVAX
23
Q
P. vivax locations
A
Caribbean
Latin America
**Rare in US and West Africa
24
Q
P. vivax diagnosis
A
GIEMSA STAIN
- Enlarged infected RBCs with SCHUFFNER’s DOTS (surface invaginations and stipling)
- Few infected cells
25
Schuffner's dots
P. vivax
26
Blackwater fever
Result of P. falciparum:
- High levels of free hemoglobin in urine
- Leads to autoimmune reaction in which host destroys kidney
- Chills, fever, rigor, dark to black urine
27
P. falciparum key points
- HIGH GRADE PARASITEMIA (all RBCs can be infected)
- Multiples rapidly
- High fever
- NO hypnozoite stage (non relapsing)
28
P. falciparum complications
- Black water fever
- Cerebral malaria
- Gastric falciparum malaria
- Algid malaria
29
Cerebral malaria
Occlusion of capillaries results in necrosis, hemorrhages, extreme fever, mania, convulsions, and death
30
Gastric falciparum malaria
Frequent vomiting in addition to other symptoms
31
Algid malaria
Skin is cold but internal temp is high
32
P. falciparum diagnosis
Erythrocytes with:
- Double or multiple ring stages
- Crescent shaped gametocyte
- MAURER'S CLEFTS
- Many infected cells
Young trophozoites and gametocytes (but NOT schizonts) observed in the periphery
33
Older erythrocytes
P. malariae
34
P. malariae key notes
- Older erythrocytes
- Paroxysms every 4th day
- Zoonotic from primate reservoir
- Basket and band shaped trophozoites
- Rosette shaped schizonts
35
P. ovale key points
- Similar to P. vivax
- Relapses common
- Common to west coast of Africa
36
P. knowlesi
- Zoonotic
- Maybe life-threatening if a heavy parasite burden
- Usually found in Southeast Asia
37
Relapses common
Vivax
| Ovale
38
Resistance mechanism of malaria species
Efflux pumps
39
Nantucket Island Fever (Babesiosis) cause
Babesia microti
40
Vector for babesiosis
Deer tick
41
Babesiosis clinical manifestations
Similar to malaria:
- Fever, chills, HA, anemia
- Small pinpoint lesions (no significant rash)
- Ranges from asymptomatic to life-threatening
42
Risk fo life-threatening babesiosis
- Immunocompromised
- Asplenic
- 50% mortality rate in Europe
43
Coinfection with babesiosis
Lyme Disease
44
Babesiosis morphology
"Cross-like" morphology in RBCs
45
Preventing babesiosis
Insect repellant
46
African sleeping sickness cause
Trypanosoma brucei
47
Chagas disease cause
Trypanosoma cruzi
48
Chaga's vector
- Triamtomine bugs ("Kissing bug")***
- Blood transfusions
- Organ tranpslants
- Congenital
49
T. cruzi life cycle
- TRYPOMASTIGOTES passed in feces of tiatomine bug at site of bite
- Trypomastigotes enter cells near inoculation site and differentiate into AMASTIGOTES
- Amastigotes replicate by binary fission in cells and differentiate into trypomastigotes
- Host cell ruptures and trypomastigotes released into circulation
- Ingested during bloodmeal by tiatomine bug and cycle starts over
50
Romana's sign
Swelling of the eyelid near the parasite entry site
51
2 stages of Chaga's Disease
Acute
| Chronic
52
Acute Chaga's
- Asymptomatic to mild manifestation
- Non-specific signs/symptoms
- CHAGOMA
- ROMANA'S SIGN (most characteristic)
*Upon waning of signs and symptoms, organism persists
53
Chronic Chaga's
- Infection may be asymptomatic for years (even for life)
- Pseudocysts of amastigotes in cells (preferentially in muscle and nerves - degeneration and necrosis)
- Chronic inflammation of organs (enlarged organs)
54
Complications of chronic chaga's
- Cardiac: Cardiomyopathy, HF, arrhythmia, cardiac arrest
| - Intestinal: Enlarged esophagus and colon
55
Chaga's diagnosis
Observe parasite on microscopy:
- Blood smear (acute phases): Trypomastigotes
- Biopsy (chronic cases): Amastigotes
Serologic tests
PCR test available
56
Chaga's prevention
- Vaccine being developed
- Spray houses with insecticides in endemic areas
- Bed nets
- Screen blood, organ, and tissue donors
- Screen newborns of infected mothers
