MIDTERM: PLASMODIUM SPP. Flashcards
● leading parasitic disease
● one of 3 major infectious disease threats
● chronic malaria leads to anemia
Plasmodium spp.
Plasmodium spp.
- Plasmodium falciparum
- Plasmodium vivax
(microscopically indistinguishable based on life cycle) - Plasmodium ovale
- Plasmodium malariae
- Plasmodium knowlesi
are 90% responsible of human malaria cases
Plasmodium falciparum & Plasmodium vivax
described in humans in the Philippines and most of Southeast Asia. a parasite of long-tailed macaques (Macaca fascicularis)
Plasmodium knowlesi
ANOPHELES MOSQUITO
principal malaria vector in the Philippines
a night biter, which prefers to breed in slow flowing, partly shaded streams that abound in the foothill areas.
ability to adapt to or utilize new habitats such as
irrigation ditches, rice fields, pools, and wells.
In Palawan, it was observed to be mildly exophagic and zoophilic.
Anopheles minimus var. flavirostris
ANOPHELES MOSQUITO
- associated with malaria transmission in the
coastal areas of Mindanao, particularly in Sulu
Anopheles litoralis
coexists with A. flavirostris in the portion of streams exposed to sunlight.
responsible for malaria transmission at higher
altitudes.
Anopheles maculatus
has the same breeding habitats and seasonal
prevalence as A. flavirostris
but prefer habitats located in forest fringe.
Anopheles mangyanus
➢ is also known as Erythrocytic Schizogony
➢ Where P. vivax and ovale forms its dormant stage and become hypnozoites
Exo-erythrocytic Cycle
MOST DANGEROUS AND DEADLY
Affects Erythrocytes of all ages
BLACK WATER FEVER (severe malaria)
o caused by hemoglobinuria (presence of hemoglobin in urine)
o characterized by intravascular hemolysis
caused by P. falciparum-induced red cell
destruction.
has Maurer’s dots - dark, irregular to commashaped cytoplasmic dots
Plasmodium falciparum
Benign Tertian Malaria
o Causes REPEATED RELAPSES from a single mosquito
o mimic those usually seen in cases of the flu, including nausea, vomiting, headache, muscle pains, and photophobia.
Most widespread
infects RETICULOCYTES
Schuffner’s dots are often present
Plasmodium vivax
Benign Tertian (same as P. vivax)
Infects RETICULOCYTES
Has Jame’s dots
Plasmodium ovale
Quartan Malaria (also known as “Malarial malaria”)
o typically experience an incubation period
of 18 to 40 days followed by the onset of
flulike symptoms.
o Cyclic paroxysms occur every 72 hours
(thus, the name quartan malaria).
Infects OLD RBCs
Has Ziemman’s dots
Plasmodium malariae
A parasite of Old World Monkeys
Long-tailed macaques (Macaca fascicularis)
Morphologically resembles P. malariae
Causes Malaria to humans and other primates
Life cycle: Microscopically indistinguishable from P. malariae
Requires infection of both mosquito and a
warm blooded host
Natural Host: Cynomolgus Monkeys
- SINTON & MULLIGANS STIPPLINGS
Plasmodium knowlesi
Differentiation of P. knowlesi and P.
malariae is achieved through ?
Polymerase Chain Reaction (PCR) Assay and Molecular characterization
MORPHOLOGICAL FEATURES
- only mature cells
- infected rbc: larger than normal, pale, often bizarre, SCHUFFNER’S DOT are often present
- MAURER’S CLEFT
Plasmodium falciparum
MORPHOLOGICAL FEATURES
- only young and immature cells
- infected rbc: larger than normal, pale, often bizarre or distorted,
- SCHUFFNER’S DOT are often present
Plasmodium vivax
MORPHOLOGICAL FEATURES
- only young and immature cells
- infected rbc: enlarged, oval in shape, often with fringed or irregular edge; SCHUFFNER’S DOT appear even with younger stages
- JAME’S DOT
Plasmodium ovale
MORPHOLOGICAL FEATURES
- only young and immature cells
- infected rbc: larger than normal, pale, often bizarre or distorted, SCHUFFNER’S DOT are often present
- ZIEMANN’S STRIPPING
Plasmodium malariae
Range from 11 days-4 weeks
PREPATENT PERIOD
- Sporozoite injection & the appearance of clinical symptoms typically
- Initial mosquito bite and exoerythrocytic cycle of malarial infection
INCUBATION PERIOD
a sudden attack or increase of symptoms of a disease (such as pain, coughing, shaking, etc.) that often occurs again and again
Paroxysms
Prodromal Symptoms
o Feeling of weakness and exhaustion
o Desire to stretch and yawn
o Aching bones, limbs, back
o Loss of appetite
o Nausea and vomiting
o Sense of chilling
At disease onset:
o Malaise
o Backache
o Diarrhea
o Epigastric discomfort
3 Stages of Classical Malaria Paroxysms:
* Coldness & apprehension
* Mild shivering quickly turns to violent teeth chattering and shaking
of the entire body
* Convulsion may last 15-60 minutes
COLD STAGE
3 Stages of Classical Malaria Paroxysms:
* Headaches, palpitations, tachypnea, epigastric discomfort, thirst, nausea and vomiting
* Temperature may reach a peak of 41°C
* Last for 2-6 hrs
HOT STAGE/FLUSH PHASE
3 Stages of Classical Malaria Paroxysms:
*Defervescence or diaphoresis
*Temperature lower over the next 2-4 hrs
* Total duration of typical attack is 8-12 hrs
SWEATING STAGE
- only infect the aging cells
Plasmodium malariae
infect young Red Blood Cell
Plasmodium vivax and Plasmodium ovale
infect all ages of erythrocytes
Plasmodium falciparum & Plasmodium knowlesi
- RENEWAL OF PARASITEMIA or clinical features arising from persistent undetectable asexual parasitemia in the absence of an exo-erythrocytic
- Recurrence of malaria due to the SURVIVAL OF THE PARASITE in the RBCs of the patient
Recrudescence
- is RENEWED ASEXUAL PARASITEMIA following a period in which the blood contains no detectable parasites
- Recurrence of malaria even though the
patient has been cured - Usually occurs with Plasmodium vivax and
Plasmodium ovale due to the reactivation of
HYPNOZOITES in the liver
Relapse
The rupturing of RBCs causes _______________ to be
released. Due to these factors, it causes the infected
body to experience the familiar symptoms of malaria:
o Fever
o Chills
o Headache
o Excessive perspiration
TUMOR NECROSIS FACTOR (TNF) & OTHER CYTOKINES
- are the ligands for rosette formation.
- adhere to parasitized and non-parasitized
Rosettins and PfEMP-1
- act like the endotoxin of gram negative bacteria, lipopolysaccharide
(LPS).
Glycosy|phosphatidylinositol (GPI)
SEVERE FORMS OF MALARIA:
● impairment of consciousness
● signs of cerebral dysfunction (delirium and generalized convulsions)
● severe hemolytic anemia
characterized by a hematocrit less than 7 g/dL and hyperbilirubinemia with levels more than 50 mmol/L
SEVERE HEMOLYTIC ANEMIA
- manifest diffuse symmetrix encephalopathy
- FATAL
o Signs & Symptoms: retinal hemorrhage, bruxism (fixed jaw closure and teeth grinding), and mild neck stiffness.
Cerebral Malaria
- is common, and it includes air flow obstruction, impaired ventilation and gas transfer, and increased pulmonary phagocytic activity
Altered Pulmonary Function
__________ reaches up to 60% of patients with severe falciparum malaria
- Serum creatinine of more than 265 mmol/L
- 24-hour urine output of less than 1 ml/kg/hr
Acute Renal Failure (ARF)
o Increases the risk of maternal death, maternal
anemia, intrauterine growth retardation,
spontaneous abortion, stillbirth, and low birth
weight associated with risk for neonatal death
PLACENTAL MALARIA
MICROSCOPIC DETECTION OF MALARIA
GIEMSA STAIN (specimen of choice) & WRIGHT’S STAIN (GOLD STANDARD)
BLOOD SMEARS( under OIO)
- used as SCREENING SLIDES, locates parasites
sitting in RBCs
Thick smears
BLOOD SMEARS( under OIO)
- used in DIFFERENTIATING Plasmodium spp.
Thin smears
Is the MEASUREMENT OF PARASITE LOAD in the sample and the indication of the degree of active parasitic infection
Parasitemia
Blood smears are usually obtained every _________
every 6-8 hours
Not seriously ill
once daily is sufficient
Seriously ill
2-3 times daily
- Immunochromatographic methods to detect
Plasmodium-specific antigens in a finger prick
blood sample - Performed in 15-30 mins without use of electricity,
special equipment, or any training in microscopy - Easily taught and interpreted
- 90% specificity
Malaria rapid diagnostic tests (RDTs)
Malaria rapid diagnostic tests (RDTs)
Antigens being targeted:
- Histidine-rich protein II (HRP II)
- plasmodium lactate dehydrogenase
(pLDH) - Plasmodium aldolase
cannot differentiate between current and past
infections and are therefore most helpful in
epidemiologic studies.
presently available methods are not capable of
making a definitive diagnosis of acute malaria
Serologic tests
to significantly enhance microscopic diagnosis of
malaria especially in cases of low parasitemia and
in cases of mixed infection
Polymerase chain reaction (PCR) techniques
ANTIMALARIAL DRUGS MAIN USES:
- preventing either the occurrence of the infection or any of its symptoms.
PROTECTIVE (prophylactic)
ANTIMALARIAL DRUGS MAIN USES:
- use refers to action on the established infection, which involves the use of blood schizonticidal drugs for the treatment of the acute attack and in the case of relapsing malaria
Curative
ANTIMALARIAL DRUGS MAIN USES:
- deterrence of infection of mosquitoes with the use of gametocytocidal drugs to attack the gametocytes in the blood of the human host; interruption of the development of the sporogonic phase
Preventive
destroy the sexual forms of the parasite in the blood
Gametocytocidal drugs
which kill the dormant forms in the liver
HYPNOZOITOCIDAL OR ANTIRELAPSE DRUGS
Inhibit the development of the oocysts on the gut wall of the mosquito
Sporonticidal drugs
TREATMENT
first line antimalarial treatment in africa
Lumefantrine
2nd line drug
QUININE SULFATE PLUS DOXYCYCLINE OR
CLINDAMYCIN
Disadvantage of Quinine: produces
toxic side effects such as cardiotoxicity
and cinchonism, characterized by
tinnitus, headache, and blurring of vision
contraindicated in pregnant women and children below 8 years.
Tetracycline
known to be effective antimalarials, although they kill the parasite rather slowly.
TETRACYCLINE and CLINDAMYCIN
- Drug of choice in severe malaria
Quinine/quinidine
drug choice for plasmodium vivax; mainstay of antimalarial treatment for the last 50 years
Chloroquine
intermittent preventive treatment combined with sulfadoxine
Pyrimethamine
severe/uncomplicated falciparum malaria
Artemisinin-based Combination Therapies (ACTs)
Classification of response to malaria
treatment can be divided into?
- early treatment failure
- late treatment failure, and
- adequate clinical and parasitological response
Early diagnosis and prompt treatment of malaria are essential for malaria control. Breeding sites of ______________should be detected early and contained.
Anopheles flavirostris
ANTIMALARIAL OF CHOICE IN PREGNANCY
Quinine plus Clindamycin taken for 7 days
- DRUG OF CHOICE FOR GAMETOCYTES AND HYPNOZOITES
- should NOT be given in pregnancy
and in children less than 4 years of age
Primaquine
Resistance of a parasite to drugs is graded according to the PATTERNS OF _______after initiation of treatment
asexual parasitemia
TYPES OF RESISTANCE OF PARASITE TO DRUGS
- is the MILDEST FORM of resistance which is characterized by initial clearance of parasites but recrudescence occurs within a month after the start of treatment
RI
TYPES OF RESISTANCE OF PARASITE TO DRUGS
- INITIAL REDUCTION IN PARASITEMIA after treatment but there is failure to clear the blood of asexual parasites and soon after an increase of parasitemia follows.
RII
TYPES OF RESISTANCE OF PARASITE TO DRUGS
-SEVEREST FORM OF RESISTANCE which parasitemia will either show no significant change with treatment or will eventually increase.
RIII
ADDITIONAL TREATMENTS
- important especially in children to prevent convulsions.
Antipyretics and sponging
administered with care to avoid pulmonary edema.
Fluid replacement or blood transfusion
o To control seizures
o 10 mg intravenous
Diazepam
