Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GORGAS > Malaria > Flashcards

Malaria Flashcards

1
Q

Species of Malria that can be dormant

A

P Vivax
P Ovale
- form hypnozoites in the liver which can lie dormant for months to years resulting in relapses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Sexual reproduction stage?
Occurs?

A

Sprogony
Occurs in anopheles mosquitoes
Mosquito takes gametocytes during blood meal
Male and female gametocytes form oocysts
Oocysts rupture to sporozoites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Asexual reproduction?

A

Schizogony
Occurs in human (ex-erythrocytic or erythrocytic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Schuffners dots

A

P vivax
P ovale

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Ziemanns stippling

A

P malariae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Sinton and Mulligans stippling

A

P Knowelsi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Maurers Clefts

A

P Falciparum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Quotidian fever

A

24hrs P Knowelsi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Tertian fever

A

48hrs:
P falciparum
P vivax
P ovale

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Quartan fever

A

72hrs
P malariae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is cytoadherence?

A

Occurs in P Falciparum
Knobs on RBC surface, cause cytoahderence
Reduces clearance from spleen as get sequestration of mature trophozoites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

If you see mature schizonts in P Flaciparum smear?

A

Hyperparasitemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Patent parasitemia
Sub patent
Pyrogenic Density

A

Detected by optic microscopy (>50 ul)
Parasites in blood but not detected by optic microscopy (<50)
PD is the level of parasitemia at which fever occurs (<10,000 in non immune)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Recrudescence vs relapse

A

Renewed detection of parasitemia arising from survival of undetectable erythrocytic parasites- often failed anti-malarial treatment
Relapse is due to hipnozoties (p ovale and p vivax)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Average incubation periods

A

P Vivax and Ovale (13 days)
P malariae (28 days)
P falciparum (12)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Hypoendemic

A

Spleen rate or parasite rate <10% in children

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Mesoendemic

A

SR or PR 11-50% in children 2-9yrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Hyperendemic

A

SR or PR >50% in children (2-9yrs)
Adult SR is also high

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Holoendemic

A

SR or PR >75%
Adult SR is low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Stable vs Unstable Malari

A

Stable malaria is found in highly endemic populations who have high immunity, epidemics are unlikely.
Unstable is low endemicity and low immunity, transmission rates vary and epidemics likely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which strain of P Vivax has long latency periods?

A

Temperate (Hibernans) and subtropical strains (St Elizabeth and Korean)
Relapse seen in 8-10 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which strain of P Vivax shows short latency?

A

Tropical strain (1 month)
Eg Chesson (New Guinea)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Premunition?

A

State of partial immunity seen in areas of stable malaria.
Asymptomatic parasitemia common, reduces asexual parasitemia and production of gametocytes. Controls, does not prevent infection
Loss of exposure, get loss of immunity (6 months)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Immunity in stable malaria

A

Infants partially protected for 3-6months (maternal IgG)
Infected young children have high parasitemia causing severe disease
Older children who survive develop premunition and adults typically have asymptomatic parasitemia, rarely severe malaria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Immunity in unstable Malaria

A

Immunity low
Severe infection in all age groups including adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Nutritional factor affecting malaria in host

A

Iron deficiency associated with reduced risk of malaria
(In areas with good malaria controlz do not withhold iron in anaemic pts)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is hereditary ovalocytosis?

A

Reduces invasion by P Falciparum and P Vivax seen in SE Asia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is Duffy negative genotype

A

Resistant to invasion by P vivax
Seen in West Africa, African and American blacks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Genetic factors inducing immunity in host

A

1) Haemoglobin S (sickle cell trait), mainly protects against severe cerebral malaria (p falciparum)
2) Duffy antigen negative (West Africa stops P Vivax invasion)
3) Heredity ovalocytosis seen in SE Asia, protective against p falciparum and p vivax

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Other host factors genetic immunity

A

B and alpha thalassemia
G6PD deficiency
Haemoglobin AC and CC- reduced cytoadherence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Anthropophily vs Zoophily

A

Anophele mosquitoe preference human vs animal blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Dominant species in Peru

A

P Vivax

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

P Vivax appearance

A

-increased RBC size
-hipnozoites round ovid body
-irregular and pale
-male gamerocytes pinkish stain, female more blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are VSAs?

A

Found in P Falciparum parasites in placenta
Cause placental sequestration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

P falciparum effects on newborn in stable malaria?

A

-Doubles risk of LBW (use chloroquine proph)
-IUGR main cause, will cause 70% IUGR and 36% preterm delivery
-Doubles risk of stillbirth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

P Falciparum effects on pregnant women in stable area

A

-primigravid at greatest risk
-often severe anaemia, can be asymptomatic
-congential malaria usually clears spontaneously

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

P Falciparum effects on pregnancy in unstable area

A

Affects all parities of women
Cerebral malaria, pulmonary edema and death
Still birth, LBW and preterm delivery 4× as high

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

P Falciparum effects on Infant in unstable area

A

Increased risk of congenital malaria (risk continues up to 6wks post delivery)
Anaemia 3x risk
Reduced transplacental maternal antibodies (reduced response to infections)
Multigravid babies at increased risk
Increases risk of disease later in life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

P Malariae Tx

A

Chloroquine Base (3 days)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

P vivax Tx

A

Chloroquine Base (3 days)
And Primaquine Base (7 days) kills hipnozoites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Uncomplicated P Falciparum Tx

A

ACT: artesunate, mefloquine, primaquine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Uncomplicated P Falciparum in Pregnant woman (1st Trim)

A

Quinine Salt and Clindamycin
For 2nd and 3rd Trim ACT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Why can you not give primaquine to children <6mths

A

G6PD deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Are hypnozoties present in congential malaria

A

NO!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What % parasitemia in severe malaria?

A

40%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Tx of P Falciparum in traveller

A

Atorvoquone/Proguanil or
Artemether/lumefatine or quinine and Doxy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Treatment of P Vivax relapse

A

Chloroquine 3 days
Primaquine 14 days

48
Q

What drugs are hepatic schizonticides?

A

Atorvoquine Proguanil
Primaquine

49
Q

What drugs are hypnozoiticides

A

Primaquine

50
Q

What drugs are blood stage schizonticides?

A

Atrovoquone-proguanil
Doxycycline
Mefloquine
Chloroquine

51
Q

Where is most imported Malaria from? Most common cases

A

88% Africa
61% west africa
Falciparum nearly every case- typically within 1 month

52
Q

Clinical Manifestations of severe malaria?

A

Any one of:
Prostration
GCS <11
Resp distress
Convulsions
Circulatory collapse
Pulmonary oedema
Abnormal bleeding
Haemoglobinuria

53
Q

Lab features of severe Malaria?

A

Severe anaemia
Hypoglycemia
Acidosis
Renal impairment
Lactate >5
Hyperbiliruninaemia
Hyperparasitemia (2% if non immune or 10% endemics)

54
Q

Hyperparasitemia in P Falciparum

A

2% non immune
10% endemics

55
Q

Binax card?

A

Malaria rapid test
Good sensitivity for P Falciparum, not the others

56
Q

Tx of Complicated Malaria

A

IV artesunate

57
Q

Tx of suspected resistant P falciparum (uncomplicated)

A

Aetemether/Lumefantrine
Atorvoquone/Proguanil
Quinine plus doxy
Mefloquine

58
Q

What tx for P Falciparum do you not give if contracted in SE Asia?

A

Mefloquone
Quinine plus doxy
Give atorvoquone/proguanil

59
Q

Where is P Knowelsi from?

A

Borneo (Malaysia)
Thailand
Philippines
Burma

60
Q

Prophylaxis Tx in Traveller

A

Atorvoquone/Proguanil or Doxycyline or Tafenoquine or Mefloquine (not SE Asia!)

61
Q

What must you do before giving tafenoquine

A

Check G6PD levels!!

62
Q

Mefloquine prophylaxis Regimen
Important SE

A

Weekly and for 4 weeks post travel
Best for longer trips
NOT for people with psychiatric disorders

63
Q

Doxycycline as prophylaxis Regimen and side effects?

A

Daily dosing including 4 weeks post travel
Photosensitivity, GI irritant esophageal ulcers, vaginal candida
Miss 1 day- get malaria

64
Q

Atrovoquone/Proguanil Tx regimen

A

Highly effective especially against P vivax
Daily plus 7 days after
V expensive

65
Q

Primaquine Phosphate as prophylaxis

A

Only recommended as alternative for P Vivax
Need to test G6PD

66
Q

Tefanoquine as prophylaxsis Regimen

A

Not in Children
Must have >70% G6PD function
Need loaded dose of once weekly and then take every day in malaria zone for 3/7

67
Q

Which countries account for almost half cases worldwide?

A

Nigeria
DRC
Uganda
Mozambique

68
Q

What can cause recrudescence?

A

Resistance (Vivax)
Incomplete treatment
Unusual PK
Immunodeficiency

69
Q

Where is seeing emerging resistance to Chloroquine in P Vivax?

A

Indonesia
Papa New Guinea
Sabha

70
Q

P Falciparum Pre patent period
Incubation period

A

9-11 days
9-14 days

71
Q

P vivax prepatent and incubation period

A

P vivax is mainly found in Asia, SA and horn of Africa
Prepatent 11-13 days
Incubation 12-17 days and 6-12months

72
Q

P ovale incubation and prepatent period

A

Can infect Duffy negative immature RBCs
Mainly subsaharan Africa
Prepatent 10-14 days
Incubation 14-18 days

73
Q

What is P Malariae associated with?

A

Nephrotic syndrome

74
Q

Why do you sometimes need PCR to speciate P Knowelsi?

A

Appearance similar to p malariae, differentiate with PCR

75
Q

Diagnosis of malaria principles

A

Need to diagnose quickly (<1hr)
Anticoagulant not recommended
Stain with giemmsa stain 7.2
Thin smear: quantification against RBC
Thick smear: quantification against WBC

76
Q

How many merozoites in schizont of P Falciparum?

A

40

77
Q

When is a thick smear inaccurate?

A

When parastie count is high

78
Q

When can a thick smear slide be pronounced negative?

A

Only when minimum of 100 fields have been examined correctly

79
Q

When is a thin smear inaccurate and when can it be pronounced negative?

A

Inaccurate when parasite count is very low
Only deemed negative when a minimum of 800 fields have been examined

80
Q

What malaria has Maltese cross

A

Babesia Malaria
Resembles Falciparum!

81
Q

Babesia species

A

B Microti (NE and Midwest USA)- usually asymptomatic
B Divergins (Europe) - severe disease
M01 found in Missouri

82
Q

How do you treat babesia malaria?

A

Atovaquone and azithromycin
Clindamycin and quinine (if severe)

83
Q

Key points for RDTs

A

1)The accuracy of diagnosis of uncomplicated P Falciparum infection is equal or superior to routine microscopy
2)Sensitivity decreases at low parasitemia
3) use in combination with microscopy!!

84
Q

HRP2 is RDT for what?

A

P Falicparum

85
Q

pLDH

A

Pan species
Can use ones with isomers for Vivax or Falciparum

86
Q

P Aldolase

A

Pan Species

87
Q

Certain requirements for a RDT to be allowed on market

A

P Falciparum and P Vivax detection score of >75%
False positive rate <10%
Invalid rate <5%
Also consider: ease, storage, price

88
Q

What causes false negatives in RDTs?

A

Low P Falciparum parasitemia
Plasmodium other than Falciparium
User interpretation

89
Q

HRP-2 causes of false negatives

A

High Falciparum parasitemia
Pfhrp2/3 Gene deletion

90
Q

Causes of false positives in RDTs?

A

Persistence HRP-2
Delayed reading
Buffer substitution
Cross reaction between species
Concomitant conditions eg chagas disease, dengue, toxoplasmosis

91
Q

Prozone effect

A

Cause of false negatives as high antibody titre interacts with formation of antibody-antigen lattice

92
Q

Where is Pfhrp2/3 gene deleted?

A

Most commonly amazon basin
Now in Mali, India, Africa
40 countries have gene deletions

93
Q

What species are RDTs not great for?

A

P Ovale
P Malariae
P Knowelsi

94
Q

What do you do of testing for P Falciparum in area where >5% missed due to pfhrp2 deletion

A

Use a combination of HRP2 and pf-LDH or combination of pf-LDH and pan-LDH

95
Q

PCR for malaria testing

A

Differentiates species
Good when low parasitemia on blood film

96
Q

When do you use malaria serology?

A

NOT in acute malaria- takes time for antibodies
Useful for screening blood donors

97
Q

When is LAMP good?

A

Context of malaria elimination
High NPV- good to r/o imported Malaria in non-endemic countries

98
Q

Define uncomplicated hyperparasitemia

A

> 4% parasitemia but no features of complicated malaria

99
Q

Severe malaria defined as? Clinical features

A

One of:
GCS<11
Prostration
More than two convulsions in 24hrs
Pulmonary oedema
Significant bleeding
Shock

100
Q

Lab categories of severe malaria

A

Acidosis or lacate >5
Hypoglycaemia
Hb <7 or hct <20 and parasite count >10,000
Renal impairment
Jaundice and parasite count >100,000
Hyperparasitemia (>10% endemic and >2% non immune)

101
Q

Examples of ACT

A

Artemether-lumefantrine
Artesunate-amodiaquine
Artesunate-mefloquine

102
Q

How long ACT

A

3 days;
Minimise resistance
Good adherence
Less risk of failure
Less risk of gametocytaemia

103
Q

How do you reduce transmission of P Falciparium

A

In low transmission areas give single dose of primaquine on first day of ACT tx
Do not need G6PD testing as v low dose
AVOID in pregnant woman and babies <6mths

104
Q

What happens if recurrence of P Falciparum?

A

If within 28 days- alternative ACT
If after- use first like ACT but avoid use of mefloquine as increases neuropsychiatric reactions

105
Q

Tx of pregnant woman in first trimester with P Falciparum?

A

Artemether-lumefantrine

106
Q

What ACT to avoid during first trim pregnancy?

A

Sulfadoxine-pyrimethamine

107
Q

What do you avoid in pregnancy and lactating women who have malaria?

A

Primaquine and tetracyclines

108
Q

What to avoid in Tx uncomplicated P Falciparum in HIV taking co-trimoxazole?

A

Avoid Artesunate-SP

109
Q

What to avoid in tx of P Falciparum malaria in HIV patient on efavirenz or zidovudine?

A

Artesunate- Amodiaquine

110
Q

Tx when malaria species unknown?

A

ACT

111
Q

Tx of Vivax, knowelsi, ovale, malariae

A

ACT or chloroquine

112
Q

If chloroquine resistance what Tx

A

ACT

113
Q

How to prevent relapse in Ovale and Vivax

A

14 days primaquine

114
Q

G6PD Def common where?

A

Africa and Asia

115
Q

G6PD genetics?

A

X linked
Much more common in men

116
Q

What time do in females heterozygous G6PD def?

A

Need quantitative test, do not give them tenefoquine

117
Q

What to do if G6PD def? (<30%)

A

8 week course of weekly primaquine

GORGAS (33 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions