B3-090 Protozoal Infections Flashcards
(127 cards)
1
Q
main species causing 95% of malaria
A
plasmodium faciparum
plasmodium vivax
2
Q
a majority of malaria in the US comes from
A
imported from visiting friends and relatives
3
Q
risk factors for malaria
A
living in an endemic area
4
Q
why are VFRs the highest risk causing malaria?
A
travel to more rural areas
poor adherence to propyhlaxis
5
Q
how is malaria most often transmitted?
A
anopheles mosquito bite
6
Q
less common transmissions of malara
A
blood transfusion
transplacental
needlestick
7
Q
incubation time of malaria
A
2 ish weeks
8
Q
which strains of malaria become hypnozoities and remain in the liver?
A
P. ovale
P. vivax
9
Q
sporozoites penetrate the hepatocyte via attachment of the sporozoitie surface protein coat to the hepatocyte heparan sulfate glycoproteins and LDL receptor
A
malaria
10
Q
diagnosis is really in thinking about it and having a low threshold of suspicion
A
malaria
11
Q
clinical presentation of malaria
A
fever, chills, headache, splenomegaly
**almost any symptom has been reported.
12
Q
3 stages of malarial paroxysm
A
- cold or chilling stage
- hot stage
- sweating stage
13
Q
cyclic fevers are a hallmark of ________ caused by ___________
A
malaria; lysis of RBCs
14
Q
tertian malaria is caused by what organisms?
A
P. vivax, P. ovale
Fevers occur every 48 hours
15
Q
Quartan malaria is caused by what organisms?
A
P. malariae
fevers occur every 72 hours
16
Q
P. falciparum causes _________ fevers
A
continuous
w/ intermittent irregular spikes
**on 48 hour cycle
17
Q
laboratory findings: malaria
A
anemia
WBC fluctuation
thrombocytopenia
evidence of hemolysis
18
Q
Sequestration is caused by __________ and results in ___________
A
P. faciparum; endothelial margination and stickiness
19
Q
why is P. falciparum the most virulent strain of malaria?
A
infects all RBCs
sequestration
20
Q
cerebral malaria
hypoglycemia
lactic acidosis
severe anemia
pulmonary edema
tropical splenomegaly
blackwater fever
are complications of which malarial organism
A
P. falciparum
21
Q
late splenic rupture is a complication of which malarial organism
A
P. vivax
22
Q
immune complex glomerulonephritis is a complication of which malarial organism
A
P. malariae
23
Q
a parasitemia >5% indicates
A
severe malaria
24
Q
risk factors for severe malaria
A
children 6 months-3 years
children and traveler’s who are not immune
25
malaria immunity requires
repeated exposure
**wanes with lack of exposure
26
in endemic areas, children are usually protected from malaria after ________ years
three
27
gold standard for diagnosis of malaria
parasites in RBC on peripheral blood smear
28
what kind of stain do you use to visualize malaria parasites in RBCs?
Giemsa stain
29
disadvantage: giema stain
requires expertise and can't be done STAT
patient deteriorate rapidly
30
antigen detection has _________ sensitivity for non-falciparum species
decreased
**always back up with smear
31
a PCR test can be performed for suspected malaria but
not commercially available, and not run STAT
32
the thick portion of a peripheral blood smear is for
a screening test
**sensitive
33
the thin portion of a peripheral blood smear is for
species identification and %parisitemia
34
how should you draw peripheral blood smears for optimal sensitivity?
3 spaced draws over 12-24 hours
35
a lateral flow assay done for malaria is detecting
HRP-1
36
con of lateral flow assay for malaria
less sensitive, must be backed up by thick smear
37
what drug is tissue schizonticidal for malaria?
primaquine
**P. ovale, P. vivax
38
what drug is the best choice for blood schizonticidal for malaria?
atovaqunone/proguanil
**resistance to chloroquine and mefloquine is growing
39
if you have clinical suspicion of malaria
perform thick and thin blood smears AND read them within hours (STAT)
40
if quindine is unavailable, contact CDC malaria hotline for
artesunate
41
what is malaria related mortality so high?
lack of prevention
diagnostic failure
management failure
42
"looks like malaria, acts like Lyme disease"
babesia
43
most common babesia species
B. microti
44
babesia is usually transmitted by
ixodes tick (NE, MN, WI)
45
rare routes of transmission for babesia
blood transfusion
transplacental
46
pathogenesis: malaria and babesia
invade RBCs
cytokine and TNF-a release
fever
causing anemia, thrombocytopenia, splenomegaly
47
incubation period: babesia
1-4 weeks
48
may-september seasonality
(75% June-August)
babesia
49
most babesia infections are
asymptomatic
50
symptoms of babesia
febrile illness with anemia
shaking, chills, fever, headache, myalgia
51
what patient population are we concerned about with a babesia infection?
asplenics
also elderly and immunocompromised
52
on physical examination of babesia infection, what would be noted?
fever, splenomegaly, hepatomegaly
53
babesia is often seen as a coinfection with
Lyme disease
54
diagnosis of babesia on blood smear is indicated by
ring forms and maltese crosses
55
treatment of mild to moderate babesia (<4% parisitemia)
atovoquone and azithromycin
56
treatment of severe babesia (>4% parasitemia)
IV azithromycin + atovoquone
IV clindamycin + quinine
57
hemoflagellates
trypanosoma and leishmania
58
two clinically important species of trypanosom
T. brucei
T. cruzi
59
epimastigote of trypansoma
found in vector
60
amastigote of trypansoma
non motile, dividing, found in tissues
61
trypomastigote
motile, non-dividing, found in blood
62
identify nucleus, flagellum, undulating membrane, and kinetoplast
63
T. brucei is transmitted by
tsetse fly
64
african sleeping sickness is caused by
T brucei
65
T. brucei gambiense is endemic to _______ Africa
western
66
T. brucei rhodesiense is endemic to ______ Africa
east
67
the primary reservoir for T. brucei is
animals
68
Stage I of a T brucei infection is characterized by
intermittent fever, headache, rash, posterior cervical lymphadenopathy, chancre at bite site
69
stage 2 of a T. brucei infection is characterized by
wasting, meningoencephalitis
headaches, phychosis, ataxia, tremor, difficulty concentrating, altered sleep cycle, convulsions
70
Which T. brucei species is the most severe, charactereized by rapid progression from stage 1 to stage 2?
T. brucei rhodesiense
71
diagnosis of T. brucei is
limited
can develop over years, so hard to get a good hx
labs are nonspecific
can see trypomatigotes in blood smear
72
chagas disease
T. cruzi (american trypanosomiasis)
73
T. cruzi is most commonly transmitted by
Kissing Bug (reduviid/triatome)
74
5-20% of T cruzi infections are transmitted via
blood transfusion
75
less common transmission of T cruzi
transplacental
transplantation
oral transmission
accidental-laboratory
76
T cruzi: slyvatic cycle exists in
US-west and South
77
T. cruzi is most prevalent in
Central and South America
**blood donors and individuals from these areas are classical presentation
78
wild and domestic animals around ________ are reservoirs of T. cruzi
rural mud/thatch homes
79
contaminative transmission
bug bites, turns around and poops into the conjunctive or it it itches and the host scratches the poop into the wound
80
T. cruzi spreads via
contaminative transmission
81
Acute chagas symptoms:
chagoma-followed by malaise and fever
romana's sign- painless unilateral edema of both eyelids
**mostly occurs in children under 15. highest 1-5
82
chronic chagas symptoms
most are indeterminate/latent phase with minimal symptoms
some progress to cardiomyopathy, GI involvement, megaesophagus, megacolon
83
T. cruzi diagnosis
clinical
acute disease: blood smears
chronic: histopath biopsy
84
the kinectoplast on T. brucei is _________ compared to T. cruzi
much larger
85
treatment T cruzi
nifurtimox
benznidazole
86
intracellular pathogens that live in the macrophage
leishmania
87
leishmania is transmitted by
sand fly
88
Old World Leishmania (mediterranean, africa, asia)
L. donovani
L. infantum
L. tropica
89
New World Leishmania (latin America)
L. chagasi
L. mexicana
L. braziliensis
90
reservoirs of Leishmania
dogs, rodents, etc
91
wet, dry, pizza-like chronic ulcer with raised borders. sporotrichoid
(variable lesions at site of inoculation)
cutaneous leishmaniasis
92
dissemination of skin to naso-oropharyngeal mucosa
erosive mucosal regions in nose, mouth, pharynx, larynx
mucocutaneous leishmaniasis
93
mucocutaneous leishmaniasis is caused by
L. braziliensis
New World
94
L. tropica associated with Gulf War
viscerotropic leishmaniasis
95
insidious onset of malaise, fever, weight loss, splenomegaly, hepatomegaly, pancytopenia
visceral leishmaniasis
caused by L donovani, L infantum
96
most severe form of visceral leishmaniasis
kala azar (black fever)
97
diagnosis Leishmania
clinical/epidemiological
aspirate spleen or bone marrow
amastigotes on slide in macrophages
98
leishmania treatment requires
expert consulations
99
is treatment required for cutaneous leishmaniasis?
no, self limited
100
definitive host for toxoplasma gondii
cats
101
intermediate host for toxoplasma gondii are infected by
fecal contamination
102
toxoplasma gondii can be transmitted to humans via
undercooked meat (tissue cyst)
contaminated food/water
transplacental
blood transfusion
organ transplant
103
toxoplasma gondii presentation in immunocompetent host
mostly asymptomatic
may be mono like-mono spot neg
104
toxoplasma gondii presentation in immunocompromised host
febrile illness with CNS symptoms, pneumonitis, chorioretinitis
**can be primary or reactivate
105
congenital toxoplasma gondii is from a _______________ infection in mother
acute primary
106
classic triad for congenital toxoplasmosis:
chorioretinitis, intracranial calcifications, hydrocephalus
107
AIDS defining illness [from this lecture]
toxoplasma gondii
108
toxoplasma gondii: diagnosis
compatible clinical syndrome
imaging
brain biopsy
IgM, IgG
109
toxoplasmosis on CNS imaging will show
multiple ring enhancing lesions
110
what would you see on tissue histopath of toxoplasma gondii?
tissue cysts- bradyzoites
free tachyzoites (cresent shaped)
111
treatment of toxoplasma gondii in newly infected women
spiramycin
112
treatment of toxoplasma gondii in immunocompromised
pyrimethamine+sulfadiazine+folinic acid
**maintenance for life
113
feeding and dividing form of amoeba
ameboid trophozoite
114
environmentally resistant form of amoeba
cyst
115
mobile form of amoeba
flagellate
116
free living means
humans play no part in life cycle
117
where are free-living amebae found
everywhere
118
Naegleria fowleri is an amoeba causing
primary amebic meningoencephalitis
119
rapid onset
severe headache
vomiting
stiff neck rapidly progresses to coma
seen in healthy children, sometimes adults
naegleria fowleri
120
Acanthamoeba and Balamuthia cause
granulomatous amebic encephalitis
121
prolonged onset
headache
low-grade fever
focal neurological deficits
seen in immunocompromised adults
Acanthamoeba (and Balamuthia)
122
acanthamoeba causes
amebic keratinitis in cornea
123
diagnosis PAM
wet mount or Giemsa of CSF
brain biopsy
124
male 18-28, contact lense wearer may be at risk for
amebic keratinitis
125
Diagnosis: GAE
brain or skin biopsy
126
diagnosis: AK
culture corneal scraping or contacts
giemsa stain
127
treatment AK
prescription eye medication
debridement
corneal transplant, enucleation
