Malaria Flashcards
Which disease transmission intensity can be measured by rates of splenomegaly? Other infections commonly causing massive splenomegaly?
- Malaria - hyperreactive malarial splenomegaly (due to recurrent infections)
- Schistosomiasis, visceral Leishmaniasis
hyperreactive malarial splenomegaly pathophysiology? Sx? Who is it dangerous in?
- Repeated infections -> overproduction on IgM. These removed by spleen which enlarges
- Spleen >10cm below costal margin, anaemia, abdo discomfort
- Pregnant - may get acute haemolysis
Hyperreactive malarial splenomegaly diagnosis? How to differentiate from lymphoma? Rx?
- Spleen >10cm below costal margin and reduces in size by 40% on antimalarial treatment
- Younger (usually <40) lymphocyte count more normal
- Chloroquine
Where has >90% vivax? Falciparum?
- Central America/ West Coast South America/ China
- Falciparum - Sub saharan Africa
Malaria life cycle. Form injected and what do these do?
Which infects RBCs?
Which is taken up by other mosquitos? Life cycle within mosquitos? How long does it last?
What form in only vivax and ovale?
- Sporozoites - infect hepatocytes and mature into schizonts (containing merozoites) which rupture.
-[Vivax and ovale some from this initial infection form hepatic hypnozoites] - Merozoites infect RBCs (as these mature in RBC form immature ring shaped trophozoites which go on to either
Produce:
- Gametocytes (male and female) taken up by mosquitos ) - to form ookinite then oocyst then oocytes in anopheles gut wall
- 10 days
Or Form mature trophozoite in RBC which turns into RBC shizon which then ruptures releasing more merozoites
- Hypnozoites
Why is falciparum more severe?
- Cytoadherance - Bind to endothelial cells in capillaries of organs -> prevents effective removal of infected cells by spleen
- Increased sequestration
- Also replicates faster
Which rbc antigen protects against vivax
- Duffy negative
Aspects of severe Malaria
Any 1 of:
- Anaemia <70g/L together with parasite count>10,000/µL
-or <50g/L in kids - Acidosis pH <7.3, bicarb <15, lactate >5
- Hypoglycaemia <2.2 mmol (<40 mg/dl)
- seizures >2,
- GCS <11
- Renal impairment Cr >265µmol/L (3 mg/dL)
- Bilirubin >50 µmol/L (3 mg/dL) together with a parasite count>100,000/µL
- Pulm oedema
- Shock (<80mmHg)
- Bleeding
- Hyperparasataemia >10%
- Black urine
Name 2 contributing factors for hypoglycaemia in Malaria
- Impaired hepatic gluconeogenesis
- Glucose consumption by parasites
- Quinine - stimulates pancreatic insulin secretion
Seen on fundoscopy of cerebral Malaria
White patches on retina (due to focal ischaemia) and haemorrhage
white-centred haemorrhages, a superficial blot haemorrhage at the fovea, mild macular whitening (black arrow) and cotton wool spot (white arrow)
Which Malaria can cause malarial nephrosis in children?
- P malariae
- Immune complex - Causes nephrotic syndrome that Doesn’t respond to steroids or Malaria eradication
Rbc on slide - looks like pair of headphones inside is typical of ?
Falciparum - actually 2 chromatin dots
Thick and thin blood films mainstay of dx for Malaria. Rapid diagnostic test can be used. What might a RDT look for? Which one specific to falciparum?
- pLDH (plasmodium LDH)
- HRP-2 (histidine rich protein 2) - falciparum
Which antimalarial most potent (fastest drop in parasite count)? Why often given in combination? Example Combination?
- Artensunate
- Can be given IV PR or oral
- Short half life *1hr and so often used in combination with other drugs ‘arteminism combination therapy’ as otherwise would need 7 day course.
- Artemether-lumefantrine
Which Quinine no longer recommended for p falcipaum
Chloroquinine - high levels of resistance
Which antimalarial for vivax and ovale in addition to choroquine? What do you need to screen for
- Primaquine 30mg for 14 days (15mg for ovale)
- G6PD
Rx of uncomplicated faciparum?
Artemisinin combination therapy 3-days
Eg Artemether/Lumefantrine
Rx severe falciparum
IV artesunate
Malaria in pregnancy rx
Still ACT
A-Lumefantrine first line
[But not A-co-trimox or A-pyronaridine]
Best evidence vector control for Malaria (2 things)
- Insecticide treated nets
- Residual indoor spraying
Malarone is? How does it work? How does this affect length of treatment when used for prophylaxis?
- Atovaquone-proguanil
- Prevents formation of schizonts ‘causal prophylaxis’
- Most other agents kill blood stage schizonts - ‘suppressive prophylaxis’
- Therefore only need Malarone for 1 week after leaving but others need to keep taking for 1 month
Malaria vector
Anopheles
Malaria reservoir
Humans
Where does the sexual multiplcation of malaria take place
In mosquitos -> form sporozoites
Called when fusion of male and female gametocyte in malaria ? type of genome
Zygote (diploid genome)
[This penetrates gut wall and produces oocyst]
Trophozoites which mature in RBCs which type causes:
-Schüffner’s dots:
- Ziemann’s stippling:
- Sinton and Mulligan’s stippling:
- Maurer’s clefts:
Schüffner’s dots: P. vivax and P. ovale; enlarge RBC
- Ziemann’s stippling: P. malariae
- Sinton and Mulligan’s stippling: P. knowlesi
- Maurer’s clefts: P. falciparum
What is the brown pigment seen in RBCs infected by malaria
haemozoin
Types of malaria and how often fevers after initial attack?
[all are daily at first)
Knowlesi - Daily
Vivax, falciparum, ovale - every 2 days
P malarea - every 3 days
Fever causes the synchronisation of erythrocytic schizogony
Which Malaria has trophozoites which disappear from blood after 16-24hrs?
Faliparum - sequestered in endothelial capillaries via cytoadherence due to PfEMP-1
[You will still see ring trophozoites and gametocytes]
2 parts of sequestration and proteins
Adherence between endothelial lining cells (ICAM-1,
intercellular adhesion molecule-1)
[I cam adhere]
knob-like projections on infected RBC surface (PfEMP-1, Pf-erythrocyte membrane protein-1): Cytoadherence.
[Pfemp through]
how many parasites to see malaria on thick film
50/microL
What 2 things can merozoites become
majority → schizonts (merozoites) (asexual)
- few → gametocytes (sexual)
Define
Patent parasitemia.-
Sub-patent parasitemia.-
Pre-patent period.-
Patent parasitemia.- Parasitemia detected by optic microscopy
(≥50 p/µL)
Sub-patent parasitemia.- Parasites present in the blood but not detected by optic microscopy (<50 p/µL)
Pre-patent period.- Time between infection and patent parasitemia
Recrudescence is? Seen in?
Renewed detection of parasitemia arising from
survival of undetectable erythrocytic parasites (persistent
undetectable parasitemia):
P. malariae, P. falciparum, P.knowlesi, drug resistant P.vivax.
What are hypnozoites also called?
exo-erythrocytic malaria parasites
What is pyrogenic density? Who is it lower / higher in?
Level of parasitemia at which fever occurs
Lower in nonimmunes (<10 000 Pf/µL)
- Higher in immunes (tolerate up to
100 000 Pf/µL).
As infection continues your PD will increase slightly - ie will have asymptomatic parasitaemia
2 ways of malaria transmission
Bite from anopheles
Inoculated with RBC eg transfusion / needles …
Congenital
Malaria Hypo vs meso vs hyper vs holoendemic
Hypoendemic: Spleen rate (SR) or parasite rate (PR)
≤ 10% in children 2-9 yo.
Mesoendemic: SR or PR 11-50% in children 2-9 yo.
Hyperendemic: SR or PR consistently over 50% in children
2-9 yo.
Adult spleen rate is also high (>25%).
Holoendemic: SR or PR consistently over 75% in children
2-9 yo.
Adult spleen rate is low.
Parasitaemia rate in infants < 1 yo is high (> 75%)
What is introduced malaria
Secondary cases acquired locally, but derived from imported cases. ie malria traveller infects mosquitos in new area
What is Authochthonous malaria
contracted locally
Premunition in malaria is? how long does it last?
State of partial immunity
- Due to continuous exposure of infective bites
- Tend to have asymptomatic parasitaemia
After 6m loss of exposure -> loss of this partial immunity
Why do babies not tend to get malaria for first 3-6 months
Maternal IgG protects
Then risk of high levels parasitaemia and death while still an infant
OR develop premunition
Which deficiencies protect against malaria ? relevance
Iron KEY [riboflavin and PABA]
Iron supplementation in people who DONT have iron deficiency is assoc with increased risk of malaria
Ie STILL GIVE iron if iron deficient
Duffy is
Duffy NEGATIVE genotype: RBC lacking Ags Fya and Fyb
Resistance to Vivax [very little vivax in west Africa]
name 3 protections against severe malaria
Hb S
Hereditary ovalocytosis
Duffy negative antigen
Thalassemia
G6PD deficiency
Hemoglobinopathies
HLA changes
Protect against cerebral/severe malaria
Flight range of anopheles
2-3km - Bit may end up on plane or ship
What affects sporogony in malaria
- Duration of the sporogony:
Optimum conditions: 25o- 30oC
Mean relative humidity ≥ 60%.
Sporogony: Ceases at To < 16oC
Slows down considerably at To > 35oC
Needs rainfall
2 key features of vivax in infected RBC
Enlarged as only invades reticulocytes
Caveolae in RBC membrane: Schüffner’s dots.
2 people who cant get primaquine
Need to screen for G6PD
[doesn’t occur much in Peru and so just given Rx]
Also don’t give during pregnancy
Pregnancy and malaria risk which pregnant women have the worst time? What happens
Young and primigravid
Increased severe anaemia
Sequestration in placenta
Key issue with falciparum and preg? why? Why not in multigravida?
Sequestration in placenta
Parasites in placenta express variant surface Ags
(VSAs) → cytoadhere to chondroitin sulphate A (CSA)
Multigravids - Develop antibodies to VSA
How long does risk of severe malaria last for pregnant women
8-10 weeks post-partum
Issues for babies with malaria-infected pregant mothers
70% of IUGR
35% of preterm delivery worldwide
Stillborn / Miscarriage
Anaemia of newborn
Long term risk of chronic diseases in later life
Uncomplicated P malariea Rx
3 days chloroquine
Uncomplicated P vivax rx
3 days chloroquine
7 days primaquine
In G6PD how can you give primaquine
Low dose 45mg instead of 210mg and only given weekly for 8 weeks
Why combination therapy in p falciparum
More effective
Less development of resistance
How long in ACT for p faliparum uncomplicated
3 days usually
[When combined with rapidly eliminated compounds
(tetracyclines, clindamycin), a 7-day course of treatment is
required.]
Why primaquine in flaciparum
Kills gametocytes
Most common ACT for uncomplicated falciparum
Artesunate
Lumefantrine OR Mefloquine
for 3 days
[+ Single dose primaquine often used for gametocytes]
1st trimeter uncomplicated falciparum
ACT
Why only primaquine after 6m old
hypnozoites only if infected by bite - Ie not from maternal blood
Falciparum Malaria in returning traveller Rx options
Atovaquone/proguanil 4 tabs qd X 3 or
Artemether/lumefantrine bid X 3 days
[or Quinine x 3 days, + doxycycline x 7 days]
P vivax in returning traveller Rx uncomplicated ? When different?
Chloroquine for 3 days + Primaquine 30 mg (base) po X 14d.
Papa new guin/ Indonesia -> treat as falciparum
Drug that can be used as a single dose for vivax Hypnozoites (but rarely available
Tafenoquine
When does anopheles bite
Night
When does anopheles bite
Night
When does anopheles bite
Night
What stage of malaria life does Malarone act on when used for prophylaxis?
Atovaquone-proguanil acts on hepatic schizonts during initial infection
When do doxycycline, mefloquine, and chloroquine act on malaria life cycle
Blood-stage schizonticides interrupt schizogony within red cells
[malarone does too but also on shizonts]
What is reccomended first line test in US for malaria
RDT: Binax card test - Antigen detection
[Only good sensitivity is for falciparum]
Which Malaria fever
Quotidian
Tertian
Quatan
Quotidian - knowlesi (daily)
Tertian - vivax falciparum ovale
Quatan - malariae 3 days
P. knowlesi usually georgraphy? mistaken for? rx?
South east asia [Monkey malaria]
Looks similar to p malariae on blood film
VERY sensitive to all antimalarials
Which malrial prophlyaxis can be used 1/week? Side effects?
Mefloquine (and for 4 weeks post travel)
Insomnia, vivid dreams, and anxiety in some patients
Where are 95% of malaria deaths? Who makes up loads of them?
Africa
Children <5 80%
Malria definitive vs intermediate host
Def - mosquito
Intermediate - human
Which malaria commonly has chronic infection (doesn’t kill you)
Plasmodium malariae
P falciparum affects what age RBC ?
Whats found in peripheral circulation
Key things found on RBC?
Pre-patent / incubation period
All ages of RBCs infected - normal size
- Usually only rings and gametocytes in the
peripheral circulation Ie Shizonts are rare
-unless very heavy burden - Characteristic Maurer’s clefts and appliqué forms
- Prepatent period 9-11 days
- Incubation period 9-14 days
What does vivax require to bind
duffy antigen
Prepatent perior of vivax
11-13 days
Pre patent period ovale
10-14 days
P malaria infects which RBCs? Parasitaemia ?
Fever cycle?
Associated with?
- Infects old RBCs - smaller
Parasitemia less than 1% - Quartan cycle (72 hours)
Long-lasting, chronic infection of senescent RBCs
Nephrotic syndrome
Which malarias have high parasitaemia
Falciparum
Knowlesi
Knowlesi infects which rbcs ? looks similar to? differentiate?
All RBCs
24 hour fevers
Looks like p malaria (mature trophozoites)
PCR
What temp is too cold for anopheles
<18
How does p faliparum get in and cause adhereance?
- RBC surface knobs (PfEMP1: major protein)
- Adhesion of RBC to the endothelium of capillaries &
venules (receptors: CD36, ICAM-1, CSA…)
Formation of rosettes with uninfected cells
What does cytoadherance and rosetting lead to?
poor tissue perfusion
organ dysfunction, anaerobic glycolysis and lactic acidosis
immune evasion
What is a rosette? Significance?
binding of two or more uninfected red blood cells (rbc) to an infected rbc
promotes RBC sequestration in the microvasculature and is associated with severe malaria
What is the new malaria vaccine?
RTS,S/AS01
(Mosquirix)
How is best to get blood for malaria film in low resource setting? Rich?
Finger prick
Venipuncture
Issues with using an anticoagulant for malaria blood film? How long before you make a blood smear ?
- Interference with adhesion of blood to slide
- Distortion of parasite morphology
- Merozoites from mature schizont may be released
- The later stages of parasites more affected.
Should make the blood smear within 1 hr
What is used to fix the RBCs in a thin smear? Which stain?What pH is perfect>
Methanol
Giemsa
7.2
What is the remnant of RBC which seen next to gametocyte called?
Laveran’s bibs (usually falciparum)
Which malaria has a large cytoplasm with ameboid appearance?
Vivax - usually with scuffner’s dots
Which malaria has a 6-14 mereozoites with large nuclei around mass of dark brown pigment?
Ovale
or malariae
What non malaria looks like p falciparum? How is it actually different?
Babesia microti
Do not produce any pigment
Babesia microti definitive host? intermediate? rx?
Ixodes tick
Mouse
[humans accidental host]
Atovaquone + Azithromycin
[AA it’s not Malaria]
Falciparum RDT vs microscopy
equal or superior to routine microscopy
which RDT is specific to falciparum ?
Histidine-rich protein 2 of P. falciparum (PfHRP2)
3 types of RDT for malaria ? Which one can’t differentiate between species
Parasite lactate dehydrogenase (pLDH)
-has a P vivax vs p falciparum isomer Pv/Pf)
Histidine-rich protein 2 of P. falciparum (PfHRP2)
-Most sensitive for Pf
Plasmodium aldolase
-Pan malarial and can’t speciate
Name 2 causes of false negative RDT in falciparum
Low P. falciparum parasitemia
- Plasmodium other than P.falciparum
- High P. falciparum parasitemia (prozone)*
- Pfhrp2/3 Gene deletion or alteration*
- User interpretation
Name 2 Causes of false positive RDT in malaria
Persistence HRP-2
Delayed reading
Buffer substitution
Cross reactions between species
- Concomittant conditions
(RF, hepatitis, schistosomiasis, toxoplasmosis, dengue, leishmaniasis, Chagas disease and human African Trypanosomiasis)
What is the prozone effect? What can you do if you suspect this?
False negative result due to too many antigens or antibodies
Can dilute sample and re test
Pfhrp2 gene deletion causes?
False negative in Pf RDT testing
how long does a RDT take?
20 mins
name 3 drawbacks of RDTs in malaria
RDT does not eliminate the need for microscopy
* False positive and false negative
Does not give parasite quantification
Can not be use to monitor malaria treatment
Very poor performance for P.ovale,P. malariae and P. knowlesi
Alternative to PCR and RDT for malaria diagnostic
LAMP testing (like Tb)
[Loop-mediated isothermal amplification test]
Almost 100% sens / spec
Which is more sensitive thick or thin smear/
Thick
Can you use RDTs to monitor treatment in malaria?
No Eg Persistnece of HRP
Rings of P. falciparum in a thick blood smear
Rings of P. falciparum in a thick blood smear
Which antimalarials act on gametocytes
ACT
Primaquine
Tafenequine
What is uncomplicated hyperparasitemia in malaria?
≥ 4% parasitaemia but no signs of severity
-Risk of severe malaria and treatment failure
What degree of parasitaemia is always severe malaria
> 10%
[usually >2% in non-immune]
Which stages of malaria does artemisinin affect? Why an extra drug?
Kills all stages of malaria
Longer acting
Clears remaining parasites and protection against resistance to the artemisinin derivate
Provide a period of post-treatment prophylaxis
Gene which gives malaria resistance to artemisinin
Pfkelch13
Rings of P. falciparum in a thin blood smear.
Why primaquine as an extra only in low transmission area?
Low transmission - infected people are symptomatic
-> can prevent reservoir
High transmission - lot of asymptomatic, infective people (with parasitaemia) about who will act as a reservoir even if you treat the symptomatic people
Rx of recurrent pf malaria following rx if <28d? If >28d?
<28 days
Use alternative ACT
After 28 days
* Use the first-line ACT
[but not mefloquine]
Which antimalarials absolute CI in pregnanacy
primaquine or tetracyclines
Rx uncomplicated vivax/ovale/malariae/knowlesi?
Chloroquine (+ primaquine in Vivax/ovale)
or ACT
In area with cloriquine resistnace
-ACT
Name 2 groups primaquine contraindicated?
Preg / breastfeeding
<6m
Rings of P. falciparum in a thin blood smear.
Malaria life cycle
In who can you use a qualitative (yes/no) test for G6PD
Men as only 1 x-chromasone
Women may be heterozygous -> need a qualatitive test
Alternative to primaquine
Tafenaquine
[Only if G6PD >70% Activity]
A 32 y.o. female from Afghanistan 35 week pregnant presents with a 3- day history of fever, chills and myalgias. She immigrated to Montreal, Canada 3 months ago. A RDT and thick and thin malaria smears are performed and P. vivax is diagnosed. Absence of severity criteria. Rx?
Baby born and has fevers and has P vivax on blood smear?
Chloroquine then weekly chloroquine prophylaxis until pregnancy and breastfeeding complete
->Primaquine
Baby gets just cloroquine (no need for primaquine)
Rings of P. falciparum in a thin blood smear.
iRng-form trophozoites of P. falciparum in a thin blood smear, exhibiting Maurer’s clefts.
Ring-form trophozoites of P. falciparum in a thin blood smear, exhibiting Maurer’s clefts.
Ring-form trophozoites of P. falciparum in a thin blood smear, exhibiting Maurer’s clefts.
Trophozoites of P. falciparum in a thick blood smear…
Apparently
Trophozoite of P. falciparum in a thin blood smear
Trophozoite of P. falciparum in a thin blood smear
Trophozoite of P. falciparum in a thin blood smear. In this figure, a gametocyte can also be seen in the upper half of the image.
Trophozoites of P. falciparum in a thin blood smear.
Gametocyte of P. falciparum in a thick blood smear. Note also the presence of many ring-form trophozoites.
Gametocytes of P. falciparum in a thick blood smear.
Gametocyte of P. falciparum in a thin blood smear. Also seen in this image are ring-form trophozoites exhibiting Maurer’s clefts.
Gametocyte of P. falciparum in a thin blood smear. Also seen in this image are ring-form trophozoites and an RBC exhibiting basophilic stippling (upper left).
Gametocyte of P. falciparum in a thin blood smear, showing Laveran’s bib. Also seen in this image are ring-form trophozoites exhibiting Maurer’s clefts.
Schizont of P. falciparum in a thin blood smear.
Schizont of P. falciparum in a thin blood smear.
Ring-form trophozoites of P. knowlesi
Band-form trophozoite of P. knowlesi
[looks same as malariae]
Mature schizont P knowlesi
Ring-form (lower right) and developing (upper left) trophozoites of P. malariae
[Just need to be able to spot there’s something there on thick film]
“Birds-eye” trophozoite of P. malariae in a thin blood smear.
Ring-form trophozoite of P. malariae
Band-form trophozoite of P. malariae
Band-form trophozoite of P. malariae
Basket-form trophozoite of P. malariae
Gametocyte of P. malariae in a thin blood smear.
Schizont of P. malariae in a thick blood
Schizont of P. malariae in a thick blood
Schizont of P. malariae in a thin blood smear.
Ring-form trophozoites of P. ovale in a thin blood smear. Note the multiply-infected RBC
Trophozoite of P. ovale in a thin blood smear. Note the fimbriation
Trophozoite of P. ovale in a thin blood smear. Note the fimbriation and Schüffner’s dots.
Trophozoite of P. ovale in a thin blood smear. Note the fimbriation and Schüffner’s dots.
Trophozoite of P. ovale in a thin blood smear.
Just need to spot there’s Malaria here as its a thick film
[Gametocyte of P. ovale (red arrow) nestled between two white blood cells in a thick blood smear.]
Microgametocyte of P. ovale in a thin blood smear. Note the elongated, oval shape and the Schüffner’s dots.
Macrogametocyte of P. ovale in a thin blood smear. Note the fimbriation.
Macrogametocyte of P. ovale in a thin blood smear, showing Schüffner’s dots.
Macrogametocyte of P. ovale in a thin blood smear. Note the fimbriation
Schizont of P. ovale in a thin blood smear. Notice the fimbriation.
Ring-form trophozoites of P. vivax in a thin blood smear
Ring-form trophozoites of P. vivax in a thin blood smear.
Trophozoites of P. vivax in a thin blood smear. Note the amoeboid appearance, Schüffner’s dots and enlarged infected RBCs
Trophozoites of P. vivax in a thin blood smear. Note the amoeboid appearance, Schüffner’s dots and enlarged infected RBCs
Trophozoite of P. vivax in a thin blood smear. The infected RBCs are also noticeably larger than the uninfected RBCs.
Trophozoite of P. vivax in a thin blood smear. Note the band-like appearance of the trophozoite in this figure that may be mistaken for a band-form trophozoite of P. malariae. Note, however, the fine, light brown pigment that is distributed throughout the cytoplasm (pigment in P. malariae is usually darker and coarser and distributed on the periphery of the cytoplasm). The infected RBCs are also noticeably larger than the uninfected RBCs.
Macrogametocytes of P. vivax in a thin blood smear. Note the enlargement of the gametocytes compared to uninfected RBCs.
Macrogametocytes of P. vivax in a thin blood smear. Note the enlargement of the gametocytes compared to uninfected RBCs.
Macrogametocytes of P. vivax in a thin blood smear. Note the enlargement of the gametocytes compared to uninfected RBCs.
Macrogametocytes of P. vivax in a thin blood smear.
Ookinete of P. vivax in a thin blood smear.
Ookinete of P. vivax in a thin blood smear.
Schizont of P. vivax in a thin blood smear.
Schizont of P. vivax in a thin blood smear.
Ruptured schizont of P. vivax in a thin blood smear, showing free merozoites and pigment.
Vivax male gametocyte
Chromatin pulled together
Falciparum - Rings and Maurer’s cleft on a thin smear
shizont falciparum
vivax - Ameboid trophozoite and Schüffner’s dot
vivax shizont
vivax gametocyte
Ovale Trophozoite and Schüffner’s dot, fimbriated RBC
Ovale Schizont and Schüffner’s dot
ovale - Gametocyte and Schüffner’s dot
malariae - Trophozoites band basket forms
malariae Schizont, rosette pattern
malariae - gametocyte
Really sick
knowlesi - Mature trophozoite band form
knowlesi - Schizont, rosette pattern
Babesia microti
- Pleomorphic (vary in shape and size) and do not produce pigment.
* Tetrad forms (Maltese cross)
* Extracellular forms
How many merozoites in Ovale vs Vivax shizont
Ovale - 6-14
Vivax 12-24
Define Imported malaria
Acquired outside a specified area in which it is found
Define Induced malaria
Acquired accidentally or deliberately by transfusion, needles, organ transplantation
Define Indigenous malaria
Naturally present in an area or country
Define Stable malaria
Areas of high endemicity (holoendemic) transmission rates are high, high levels of immunity in the population, epidemics are unlikely
What is unstable malaria in a location?
Areas of low endemicity, transmission rates vary, immunity is low in the population, epidemics are likely
ruptured spleen in which malaria
more common in P. vivax malaria
Severe malaria definition in kids
-Anyone unable to take oral therapy
-Prostrated: unable to sit upright, or to drink in the case of children too young to sit
-Comatose: unable to localize a painful stimulus
-in respiratory distress: acidotic breathing nasal flaring
- intercostal indrawing
- deep (acidotic Kussmaul breathing)
- >2 seizures
Severe malaria definition in kids
-Anyone unable to take oral therapy
-Prostrated: unable to sit upright, or to drink in the case of children too young to sit
-Comatose: unable to localize a painful stimulus
-in respiratory distress: acidotic breathing nasal flaring
- intercostal indrawing
- deep (acidotic Kussmaul breathing)
- >2 seizures
Compared with adults, children with severe malaria are more likely to?
- Raised intracranial pressure
- Impaired oculo vestibular reflexes
- Flaccid muscle tone
- Convulsions
name 3 long-term sequelae of cerebral malaria
Cortical blindness
Involuntary movements
Hemiplegia
Spasticity
Cognitive and learning defects
Who should get Intermittent Preventive Therapy for malaria?
What is it?
Recommended for all pregnant women in moderate
high malaria
At 4 antenatal checks (2nd and 3rd trimesters) give - 3 tabs of Sulfadoxine
pyrimethamine (SP) by Directly Observed Treatment (folic acid)
Suspected severe malaria pre-hospital Rx in children
Pre-referral rectal artesunate for children
name 3 causes of treatment failure in malaria
Delayed presentation, diagnosis, treatment
The inappropriate drug, dose, route of administration
Incomplete course, poor bioavailability
Drug resistance (against artemisinins and ACT partner drugs)
Fake or substandard drug
P vivax positive in pregnancy rx?
Either Arteether/lumefantrine or
Chloroquine
Then option for chloriquine prophylaxis
Primaquine after finishing breastfeeding
3M congo
3 days fever and disorientation
1 day of : sulfadoxine/pyrimethamine
Hb 5.1 + p falciparum in blood
rx?
When transfuse?
IV artesunate + Ceftriaxone (10% severe malaria have bacteraemia)
Transfuse if Hb <4,
4-6 with respiratory distress / CV instability
Which malaria RDT is affected by the prozone effect
Only HRP-2
Which ACT is not good for vivax infection
Artesunate+sulfadoxine/pyrimethamine
1st line ACT in pregnancy
Artemether/lumefantrine
Why not primaquine during pregnancy
Baby might have G6PD
Why gram-negative sepsis in severe malaria
Micro-occlusions including bowel -> translocation
ACT options - just recognise them
artemether + lumefantrine
artesunate + amodiaquine [not with EFV (hepatitis) or AZT (neutropenia)]
artesunate + mefloquine
artesunate + sulfadoxine-pyrimethamine [not HIV pts with h/o TMP-SMX or first trimester]
dihydroartemisinin + piperaquine
artesunate + pyronaridine [not first tri]
