PR MALARIAL Flashcards
Intracellular protozoans
Malarial Parasites
Phylum of Malarial Parasites
Phylum Apicomplexa
Life cycle of Malarial Parasites
alternating sexual (sporogony) and asexual
stages (schizogony)
Vector of Malarial Parasites
Female Anopheles minimus flavirostris mosquito
Immediate Host
Man
Habitat
Livers and RBCs of humans
Infective stage to mosquito
gametocytes
Infective stage to man
sporozoites
MOT
mosquito bite, blood transfusion, congenital
Asexual cycle of parasite
Exo-erythrocytic cycle / Schizogony Cycle
where does schizogony cycle happen
in liver cells
life cycle when Mosquito bites human, injects sporozoites
Schizogony cycle
EXO-ERTHROCYTIC CYCLE
minutes before it reaches liver
30-40 minutes
merozoites undergo asexual reproduction
schizogony
what cells do sporozoites infect
liver cells
dormant merozoites seen in P. ovale and P. vivax
hypnozoites
life cycle when merozoites from liver infect RBCs
Eryrthrocytic cycle
sexual cycle
Sporogonic cycle
entire cycle of mosquito (days)
8-35 days
Sequential Phase of Paroxysms
- Chills
- Fever
- Sweating / Diaphoresis
- Normal
pigment found in Plasmodium species as a result of the parasite feeding on hemoglobin
Hemozoin
Most prevalent Plasmodium in the Philippines
Plasmodium falciparum
P. falciparum
Merozoites develop in _______
parasitophorous vacuolar membrane (PVM)
P. falciparum
what happens when merozoites invade RBCs
RBC reduce their deformability
P. falciparum
Type of Malaria
Malignant Tertian Malaria
P. falciparum
Paroxysmal Cycle
36-48 hours
P. falciparum
Type of RBC infected
Size of Parasitized RBC
Type of RBC infected - all forms
Size of Parasitized RBC - normal
P. falciparum
Presence of RBC stages
Ring forms, gametocytes
P. falciparum
Ring Forms
- 2 chromatin dots
- multiple ring forms
- has Accole/applique
P. falciparum
Developing Trophozoite
Merozoites
- Developing Trophozoite : Heavy ring forms
- Merozoites : 20-24
P. falciparum
Schizont (# of merozoites)
8-36
Average : 22-24
P. falciparum
Microgametocyte
Macrogametocyte
- Microgametocyte : Sausage shaped & Diffuse Chromatin
- Macrogametocyte : Crescent shaped & Compact Chromatin
seen in macrogametocyte of P. falciparum and is a remnant of RBC
Laveran Bib
P. falciparum
Stipplings
Maurer’s Cleft
P. falciparum Incubation Period
8-11 days
P. falciparum
where does schizogony occur
internal organs
metabolic product of parasite
Hemozoin
most severe clinical manifestation of P. falciparum
Cerebral malaria
happens if malaria if complicated and not treated immediately
Cerebral malaria
Massive intravascular hemolysis and hemoglobinuria due to P. falciparum
Severe blackwater fever
Increase in RBC destruction leads to release of hemoglobin in the urinary system
Hemoglobinuria
Causes abdominal pain, hepatomegaly, upper GI bleeding, nausea (with or without
jaundice)
Dysenteric Malaria
Rapid development of hypotension
Algid Malaria
Because of hemoglobin to the kidneys
Acute renal failure
Blood clots form throughout the body (blocking the small blood vessels)
Disseminated intravascular coagulation (DIC)
P. falciparum
Shortest pre-patent period
9-10 days
P. falciparum
Pre-erythrocytic stage
5 1⁄2 - 7 days
concept of Recrudescence
renewal of parasitemia from persistent undetectable asexual parasitemia
Most prevalent species (widest distribution)
Plasmodium vivax
Target RBC of P. vivax
Young RBCs - reticulocytes
T/F Relapses can occur in P. vivax
True
what is more severe ovale or vivax
vivax
P. vivax
Incubation period
Pre-patent period
Pre-erythrocytic stage
- Incubation period : 8-17 days
- Pre-patent period : 11-13 days
- Pre-erythrocytic stage : 6-8 days
P. vivax
Type of Malaria
Benign Tertian Malaria
P. vivax
Paroxysmal Cycle
48-72 hours
P. vivax
Type of RBC infected
Size of Parasitized RBC
Type of RBC infected : Young RBCs
Size of Parasitized RBC : enlarged RBCs (1.5-2 times)
P. vivax
Presence of RBC stages
All stages present
P. vivax
Ring forms
- Large ring form
- Big/heavy chromatin dot
- Signet ring appearance
P. vivax
Developing Trophozoite
Ameboid/bizarre looking
P. vivax
Schizont
12-24 merozoites
P. vivax
Microgametocyte
Macrogametocyte
Microgametocyte : round, large pink to purple chromatin mass
Macrogametocyte : round, eccentric chromatin mass
P. vivax
Stipplings
Schuffner’s dots
- infected RBC with red dots
Infections usually benign
Plasmodium ovale / vivax
occurs after 6-10 paroxysms
Spontaneous recovery
P. ovale
Presence of 2 distinct nonrecombining species
- Classic: Plasmodium ovale curtisi
- Variant: Plasmodium ovale wallikeri
P. ovale
Incubation period
Pre-patent period
Pre-erythrocytic stage
Incubation period: 10-17 days
Pre-patent period: 11-13 days
Pre-erythrocytic stage: 9 days
P. ovale
Type of Malaria
Ovale Tertian Malaria
P. ovale
Paroxysmal Cycle
48 hours-72 hours
P. ovale
Type of RBC infected
Size of Parasitized RBC
Type of RBC infected : Young
Size of Parasitized RBC : Enlarged RBC with serrated or fimbriated edge
P. ovale
Presence of RBC stages
All stages present
P. ovale
Ring Forms
Large rings
P. ovale
Developing trophozoite
- Non-ameboid
- Ring-shaped
- Similar to vivax
- Serrated/fimbriated
P. ovale
Schizont
8 merozoites
P. ovale
Microgametocyte
Macrogametocyte
Microgametocyte : round gametocytes
Macrogametocyte : Smaller than P. vivax
P. ovale
Schizont
8 merozoites
P. ovale
Stipplings
James’ dots
plasmodium with longest incubation
Plasmodium malariae
P. malariae
Type of Malaria
Quartan Malaria
P. malariae
Paroxysmal Cycle
72 hours
P. malariae
Type of RBC infected
Size of Parasitized RBC
Type of RBC infected : Old RBCS (Senescent RBCS)
Size of Parasitized RBC : Normal
P. malariae
Presence of RBC stages
Few ring forms seen (mostly trophozoites and schizonts)
P. malariae
Ring Forms
- Heavy chromatin dot (bird’s eye appearance)
- Small form
P. malariae
Developing Trophozoite
Band formation or Inverted basket form
P. malariae
Schizont
- 6-12 merozoites
- rosette/fruit-pie appearance
P. malariae
Microgametocyte
Macrogametocyte
Microgametocyte : Round gametocytes
Macrogametocyte : Same ^^ (smaller than vivax)
P. malariae
Stipplings
Ziemann’s dots
Quartan Malaria incubation period
27-50 days (longest)
Complication of P. malariae
- Nephrotic syndrome is common
- Immune complex deposition (antigen-antibody complex) in the glomerulus/kidney
same morphology with malariae and differentiated through molecular methods (PCR) and molecular characterization
Plasmodium knowlesi
P. knowlesi
Type of Malaria
Simian Malaria, Quotidian Malaria
P. knowlesi
Paroxysmal Cycle
24 hours (has the shortest erythrocytic cycle)
P. knowlesi
Type of RBC infected
Size of Parasitized RBC
Type of RBC infected : can infect all
Size of Parasitized RBC : normal
P. knowlesi
Ring forms
- Early ring form: like falciparum
- Later ring form: like malariae
P. knowlesi
Developing Trophozoite
Band formation
Plasmodium that undergoes recrudescence
P. malariae and P. falciparum
Plasmodium that undergoes relapse
P. ovale and P. vivax
Primary mosquito vector
Anopheles minimus flavirostris
Characteristics of Anopheles minimus flavirostris
- Only female bites (for egg nourishment and ovulation, males only go to flowers)
- Night biter (10pm – 2am)
- Exophagic and Endophagic
- Antropophilic and zoophilic
Transmits malaria in hilly or high altitudes
Anopheles maculatus
Characteristics of Anopheles maculatus
- Zoopholic
- Exophagic
transmits in coastal areas
Anopheles litoralis
Characteristics of Anopheles litoralis
- larvae breeds in salt or brackish (mix of fresh and salt water) waters
- anthropophilic
- exophagic
transmits in forest-fringe areas
Anopheles mangyanus
transmits in forests
Anopheles balabacensis
secondary vector of malaria in the country
Anopheles balabacensis
Characteristics of Anopheles balabacensis
- breed in stagnant water, hoof prints (when water goes inside the prints), dug wells
- anthropophilic
primary mosquito vector in Africa
Anopheles gambiae
Reason why Anopheles gambiae best vector of malaria
- bites humans only
- longer life span compared to other species
- more time to bite people
A sequence of Chills, Fever, and Sweat and a characteristic periodicity
Classical Paroxysm
Intense Cold phase that would last for ________ mins
15 - 60 mins
what happens during
Chills
- Shatter (vigorous shivering)
- There is muscle contraction
- Coincide with the bursting of RC
what happens during
Fever
- There will be a release of fever-inducing substances
can promote inflammation - Intense Heat, drying burning skin
- Throbbing headache
Fever-inducing substances
- Release of pyrogens
- Release of tumor necrosis factor (TNF) that
Duration of Fever
2-6 hours
Duration of Sweating
2-4 hours
what happens during
Sweating
- The body cannot maintain the high body temperature, and the body will decrease this by sweating
- There will be profuse sweating
- Exhausted and weak → sleep
Pathogenesis is due to
- RBC hemolysis
- Release of parasite metabolites
- Immunologic response
- Malarial pigment (hemozoin)
3 components of apical complex
rhoptries, dense granules, micronemes
Purpose of apical complex
cell invasion to the host cell
Formation of knobs on infected RBCs
Cytoadherence
What does P. falciparum form during cytoadherence
parasite forms parasitophorous vacuole in the RBC (merozoite is inside)
bind and attach RBCs to the wall of the blood vessels
PfEMP1
main component of the knob
PfEMP1
PfEMP1
Plasmodium falciparum erythrocyte membrane protein
receptors on surface of blood vessels
ICAM-1
ICAM-1
intercellular adhesion molecule 1
Sample used for laboratory diagnosis
capillary blood, peripheral blood
gold standard for detecting Plasmodium spp.
microscopic examination of the thick and thin smear
purpose of thick smear
quantification and screening of parasite
purpose of thin smear
species identification
other diagnostic method used
Quantitative Buffy Coat (QBC)
stain used in QBC
acridine orange stain
seen when Plasmodium is detected using QBC
(+) bright green and yellow under fluorescence
microscope
Antigen produced by Falciparum trophozoite and gametocytes
HRP-II: histidine rich protein
can distinguish Falciparum from non-Falciparum
species
pLDH: parasite lactate dehydrogenase
Main treatment for uncomplicated P. falciparum, vivax,
malariae, and ovale
Chloroquine
WHO recommended drug for falciparum and malariae
Arthemether combination treatment
severe malaria and DOC for pregnant women
Quinine
severe malaria
Artesunate
relapsing vivax or ovale malariae
Primaquine
not given to women and children (target the bones)
Doxycycline
Prevention for Plasmodium spp.
- Early diagnosis
- Prophylaxis
- Use of insecticide treated nets and repellants (target
vector) - Use of larviparous fish (prevent transmission)
- Use of larvicides (kill larva)
(secretes toxin that kills larva) - Health education
- No clear vaccine