(22 & 23) Parasitology - Malaria

Explain the renal affection In plasmodium malariae (benign quartan malaria)

kidney infection may occur due to the deposition of immune complexes in the glomerular tubules leading to nephrotic syndrome (malarial nephrosis)

The life cycle of plasmodium (inside human body) begins in human _____________ and then continues in __________. It is therefore an_______________ parasite

liver RBCs intra-erythrocytic

what is the habitat for the plasmodium species inside the human body

liver cells then red blood cells (intra erythrocytic)

The anopheles is a vector that transmits the disease _____________. And the mode of transmission is _______________.

malaria cyclo-propagative

plasmodium _____________ is also prevalent in tropics and subtropics, but is less common than plasmodium_________________

malariae falciparum

Plasmodium falciparum causes

malignant tertian malaria

Plasmodium ovale causes what type of malaria

ovale tertian malaria

The most common species (of plasmodium) that causes malaria in tropical and subtropical areas is?

p. falciparum

what happens to patient during cerebral malaria?

patient presents with loss of consciousness, rapidly progress to coma due to hemorrhage around the blocked vessels.

Species of genus___________ infect human causing malaria

plasmodium

What is the fate of early forms of sporozoites

produce schizonts

Recrudescence happens as a result of?

reactivation of blood stages surviving in small numbers in RBCs after primary infection. The parasites remain dormant in the RBCs (due ti inadequate treatment) until he host's immune response becomes weaker, and then they multiply to a level sufficient to cause clinical illness once more.

Relapse happens as a result of?

reactivation of dormant hypnozoites lying within the hepatocytes with formation of liver schizonts that rupture releasing merozoites that invade RBCs

The merozoites liberated from the liver invade the __________

red blood cells

when the hypnozoites are reactivated it is called

relapse

what is the fate of late form of sporozoites (hypnozoites)

remain dormant up to several years in the liver cells

Malarial paroxysm attacks are due to?

rupture of RBCs with release of toxins, parasite debris, malarial pigment and pyrogens.

Paroxysmal periodicity corresponds to the duration of te erythrocytic ______________ cycle

schizogony

During the exo-erythrocytic schizogony cycle, the sporozoite undergoes changes in shape and multiplies in the liver parenchymal cells forming a stage called

schizont

Pulmonary edema and atypical pneumonia is caused by the _____________ of parasitized red blood cells in the _______ and increased leakage from the pulmonary vasculature

sequestration lung

The plasmodium species divides both __________ and ______________

sexually (inside mosquito) and asexually (inside human)

A thin blood film form it's an easier morphologic differentiation to identify ____________. Thick smear permits easy detection of ________ because of ____________________

species parasites hemolysis of RBCs (screening and concentration)

The sexual stage in the life cycle of the plasmodium is also called____________ and it happens in ______________

sporogony the vector

Fine or coarse granules appear in the infected RBCs due to cytoplasmic damage by the growing parasite, this is called ___________

stippling

Presence of dots or clefts on the red blood cell is called__________

stippling

What is the hemoglobin index

the percentage of population examined having reduced hemoglobin level (anemia)

what is the parasitic index

the percentage of population examined whose blood contains the parasite

What is the splenic index

the percentage of the population examined having splenic enlargement

In plasmodium falciparum, infections trophozoites and schizonts are sequestered in the amall blood vessels of the internal organ. This leads to ____________

vascular obstruction

Infected RBCs are enlarged in plasmodium __________ and ___________

vivax ovale

Relapse occurs only in plasmodium ________ or ____________

vivax ovale

In plasmodium ovale, the wall of the erythrocytes tends to be __________ and acquires an oval shape while spreading the blood film.

weak

Malaria parasite passes its life cycle in 2 hosts. mention them

1-Definitive host: Female Anopheles mosquito. 2-Intermediate host: Man.

Is there a reservoir host for the plasmodium parasite?

No- EXCEPT in plasmodium malariae, chimpanzee may act as a RH

Which index is more indicative, sporozoite or oocyst index? and why?

Sporozoite index is more indicative, because oocysts may not develop into sporozoites.

What are the modes of infection of malaria?

1. Bite of female Anopheles (infective stage is sporozoites) 2. transfusion malarial: if blood donor with latent infection is used in blood transfusion. 3. Accidental malaria: due to common use of syringes 4. Congenital malaria: from mother to fetus.

What is the phylum of the genus plasmodium

Apicomplexa

The paroxysm attack in P. Malariae is repeated every __________ day. Infection is usually ________

fourth (quartan malaria) Mild

Anopheles ______________ is the most efficient malignant malaria vector. While Anopheles ______________ and _______________ are the chief vectors of human malaria in Egypt.

gambiae Pharoensis and Sergenti

The clinical incubation period in malaria is____________. This is the time elapsing between inoculation of sporozoites and first appearance of characteristic malaria paroxysm.

1-5 Weeks (according to the species)

The clod stage lasts for ______ hour. Patient feels ___________, _________, resulting in ______________.

0.5 - 1 hour cold Shivering shaking chills

The sweating stage of paroxysm attack lasts for ______ hours. What happens to the patient during this phase?

1 - 2 hours Temperature falls and the headache disappears. Patient feels fatigued and exhausted. Herpes labialis frequently occurs in established malaria.

Vascular obstruction of the small blood vessels in vital organs as brain, intestine, lung, heart & suprarenal gland results in severe complications as in:

1. Cerebral malaria 2. Gastrointestinal disturbances 3. Pulmonary edema and atypical pneumonia 4. Degeneration of heart muscle 5. Algid malaria 6. Congenital malaria 7. Renal affection

List the three stages of the paroxysm attack os malaria

1. Cold stage 2. Hot stage 3. sweating stage

What is done during the malaria survey for the anopheline factor?

1. For larvae: Survey of Anopheles larvae and detection of the prevalent species 2. For adults: survey of adult female Anopheles and detection of prevalent species and their habits. (oocyte index and sporozoite index)

Mention the steps of the life cycle of Plasmodium inside the vector (sporogony cycle)

1. In the midgut of female Anopheles, all ingested stages are digested except gametocytes --> complete the cycle 2. The male (micro) gametocyte undergoes a process of exo-flagellation where the nucleus divides into 4-8 fragments by reduction division then separate as microgametes. 3. The female (macro) gametocyte maturates into macrogamete by reduction division. So, microgametes and macrogametes have haploid number of chromosomes 4. Union of micro and macrogametes --> zygote is formed --> transforms into a motile and elongated ookinete. 5. Ookinete penetrates the wall of the gut and transforms under the basement membrane into circular body--> the oocyst which matures into sporocyst. containing thousands of sporozoites. 6. Sporocyst ruptures and the liberated sporozoites enter the mosquitoes body cavity and migrate to the salivary glands. They enter the new host's blood with he next feed. The developmental cycle in the mosquito takes about 1 and 4 weeks.

Very briefly, list what happens during the erythrocytic schizogony cycle of the plasmodium parasite inside the red blood cells

1. Merozoites multiply through the following stages: "ring forms" then "growing trophozoite" 2. the nucleus of the trophozoite begins to divide (merogony or schizogony) , producing 6-24 merozoites. 3. merozoites are liberated from the red cell and reinvade other red cells and the cycle of the erythrocytic schizogony is repeated.

What are the direct methods to test for malaria

1. Microscopy 2. Blood concentration technique as quantitative Buffy coat 3. Detection of circulating antigens (rapid) 4. Detection of plasmodium specific genes by PCR

What are the three indexes we survey in the human factor (during malaria survey)?

1. Parasitic index 2. Splenic index 3. Hemoglobin index

List the four species of plasmodium (that cause malaria)

1. Plasmodium falciparum 2. Plasmodium vivax 3. Plasmodium ovale 4. Plasmodium malariae

list what happens to the plasmodium parasite inside the liver cells (exo-erythrocytic schizogony cycle)

1. Sporozoites are injected with the saliva of the biting female anopheles mosquito 2. Within 30 mins, each sporozoite attacks a liver parenchymal cell, undergoes changes in shape and multiplies forming a stage called schizont containing thousands of merozoites (meronts) 3. Liver cell then ruptures releasing merozoites into the blood 4. The merozoites liberated from the liver invade red blood cells

List the symptoms and signs of Malaria.

1. The paroxysm (through 3 stages) 2. Hemolytic anemia 3. jaundice 4. Enlarged tender liver and spleen

What are the complications of malaria

1. Vivax, ovale, and malariae are relatively benign 2. In falciparum malaria infection is usually sever.

Enlarged tender liver and spleen in malaria is due to hyperplasia of reticuloendothelial cells in response to the three things. Mention them

1. release of merozoites 2. pigments 3. remnants of ruptures RBCs (debris)

Species identification of plasmodium is possible on the basis of three things. Mention them

1. shape and size of the intra-erythrocytic parasitic stages. 2. Developmental stages found in peripheral blood. 3. Modifications of infected erythrocytes.

Very briefly, list what happens during the gametogeny cycle of the plasmodium parasite inside the red blood cells

1. some mrozoited do not repeat the schizogony cycle, and rather develop into gametocytes. 2. The gametocyte do not develop any further in the human host. 3. Gametocytes continue their development if ingested by a feeding female Anopheles mosquito (male do not feed on blood)

Within how many minute does each sporozoite attack a liver parenchymal cell after it has been injected with the salive of the anopheles?

30 mins

The hot stage of paroxysm attack lasts for ______ hours. There is?

4 - 6 hours fever hot dry skin flushed face full rapid pulse headache nausea vomiting convulsions (in children)

Explain the renal affection In plasmodium falciparum (malignant malaria)

A. Acute tubular necrosis due to anoxia B. Black water fever: may be the result of repeated attacks of plasmodium falciparum infection and incomplete quinine treatment.

Malaria survey includes two factors. what are they?

A. Human factor B. Anopheline factor

Recrudescence occurs in _________ species of plasmodium

All

The life cycle of malarial parasite comprises of 2 stages:

Asexual phase occurring in humans Sexual phase occurring in mosquito

What are the indirect method to test for malaria

Detection of antibodies in serum by serological tests as IHA, IFAT, and ELISA; important for screening blood donors.

What is oocyst index?

Dissection of guts to detect the percentage of mosquitoes having oocysts.

What is sporozoite index?

Dissection of the salovary glands to detect the percentage of mosquitoes having sporozoites.

What are the different intra-erythrocytic parasitic stages

Early trophozoite (ring form) Late trophozoite Schizont Macro- and micro-gametocytes

The methods of transmission: transfusion, accidental, and congenital result in ___________________ only. With no liver phase, so no __________ occurs.

Erythrocytic cycles Relapse

What is the definitive host for the plasmodium parasite?

Female Anopheles mosquitoes (vector)

Anemia is severe in plasmodium falciparum due to?

Heavy parasitemia, release of large numbers of merozoites from liver schizont, infection of all ages of RBCs and rupture of parasitized and non parasitized RBCs.

the malaria parasite, when inside RBCs, feeds on ___________. Its digestion results in the formation of _________________ composed of _____________ trapped in the cytoplasm of the parasite .

Hemoglobin malarial pigment hematin

Explain the procedure of the blood concentration technique as quantitative Buffy coat

In this technique, anti-coagulated blood is centrifuged in a capillary tube coated with the fluorescent dye acridine orange. Following centrifugation, malaria parasites are concentrated below the buffy coat layer.

What is malaria survey?

It is the examination of a locality for malaria to get information that allows proper control.

Falciparum malaria is severe due to the sequestration of RBCs. When does sequestration (cytoadherence) occur?

It occurs as erythrocytes infected with trophozoites and schizonts of plasmodium falciparum adhere to each other, to uninfected erythrocytes (resetting) and to specific receptors of blood capillaries. This can lead to capillary blockage with hemorrhages.

__________ is the most important parasitic disease of man. Approximately _______% of the world's population is infected causeing over____________ deaths each year.

Malaria 5% 1 million

How does congenital malaria occur

Malaria is transmitted from mother to fetus due to the formation of infarctions in the placenta or when umbilical cord is cut.

Intermediate host for the plasmodium parasite is?

Man (where asexual reproduction happens (schizogony)

Each schizont contains thousands of___________

Merozoites (meronts)

What is the gold standards of diagnosis of malaria? and define it.

Microscopy: demonstration of the parasite in thin and thick blood film stained with Giemsa or Leishman stains. samples are best taken during the attack

In which species of plasmodium do the sporozoites develop at different rates resulting in the formation of early and late forms.

P. Ovale P. vivax

In which species of plasmodium do sporozoites develop uniformly producing schizonts at the same time (not at different rates)? And therefore they have no____________

P. falciparum and P. malariae NO hypnozoites

Degeneration of heart muscle is due to?

Partial blockage of myocardial capillaries

What is the least common malaria parasite of humans? ____________. It is restricted to_________

Plasmodium ovale Africa

Plasmodium malariae causes what type of malaria

Quartan malaria

What is the meaning of recrudescence?

Recurrence of symptoms and reappearance of the parasite in peripheral blood film within a few weeks to dew years after apparent cure of primary infection.

What is the meaning of relapse ?

Recurrence of symptoms and reappearance of the parasite in peripheral blood film within few weeks to few years after apparent cure of primary infection.

The asexual stage of the plasmodium life cycle is also called____________ and it happens is ___________

Schizogony the human liver cells and RBCs

what is the infective stage of the plasmodium parasite?

Sporozoite

What determines the degree of parasitemia?

The number of merozoites released from each liver schizont

What is responsible for the febrile paroxysms characterizing malaria

The rupture of the mature schizonts, releasing large quantities of pyrogens

Advantages of Detection of circulating antigens technique

These tests are simple, rapid, sensitive, and highly specific.

The paroxysm attack in P. falciparum is repeated every __________ day or____________: This is because there is no _____________

Third (Malignant tertian malaria) irregularly: since there is no synchronicity in rupture of schizonts.

The paroxysm attack in P. Vivax and Ovale is repeated every __________ day. Relapses may occur every few __________.

Third (benign tertian malaria) Months

Autoimmune severe intravascular hemolysis of parasitized and non-parasitozed RBCs may occur leading to_______________, ___________________,____________________, and ______________. It maybe autoimmune phenomena due to the development of antibodies of infected RBCs.

acute tubular necrosis haemoglobinuria black discoloration of urine renal failure

In plasmodium vivax, plasmodium ovale, and plasmodium malariae ________ erythrocytic stages can be found. In plasmodium falciparum only _________ and __________ are found (due to sequestration of infected RBCs in deep blood vessels)

all rings and gametocytes

Blood stages of malaria should be differentiated from those of ________

babesia

why is the phylum named "Apicomplexa"

because they possess a structure called the apical complex, by means of which they attach to and penetrate host cells.

The predominant type of malaria in most parts of the world is

benign tertian malaria

plasmodium vivax causes what type of malaria

benign tertian malaria

Algid malaria is due to _________ of the small blood vessels of the ____________________ leading to circulatory collapse with ____________ and _________________ with rapid weak pulse and cold skin.

blockage suprarenal glands hypotension hypothermia

Explain the gastrointestinal disturbances that happen in malaria due to vascular obstruction

blockage of intestinal capillaries causes congestion and sloughing of intestinal epithelium resulting in dysentery or profuse diarrhea in severe cases

Hemolytic anemia in malaria is due to?

destruction of great numbers of erythrocytes with reduction of hemoglobin.

laboratory diagnosis of malaria include:

direct methods indirect methods

Malaria is suspected in any person coming from or visiting an ____________ area and presenting with suggestive symptoms and signs as fever, rigors, _________________, _____________, _____________, and even ___________

endemic/ malarious splenomegaly anemia jaundice coma

The cycle of division the parasite plasmodium undergoes in the liver cell is called

exo-erythrocytic schizogony

Plasmodium ____________ produce 40,000 merozoite per____________

falciform per schizont !!!!!

All erythrocytic stages circulate in blood except in plasmodium _______________ infections, in which only early trophozoites (rings) and gametocytes appear in peripheral blood.

falciparum

Splenic rupture may occur especially in ______________ malaria

falciparum

Plasmodium __________ invades RBCs of all ages, while plasmodium _________ invades young RBCs.

falciparum vivax

highest parasitemia occurs with plasmodium _____________

falciparum (40,000 merozoite/ schizont)

What are the prodromal symptoms of malaria (which happen during early cycles of multiplication) include _____________, ___________, _____________. In non endemic areas, the disease is misdiagnosed as __________

headache, bone aches, irregular fever influenza

jaundice in malaria is due to ________________ as free Hb is changed to _____________

hyperbilirubinemia bilirubin

the late form of sporozoites produced by P.ovale and P. vivax is called

hypnozoites