Malaria: Causes and Parasites
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Questions and Answers

What is the main cause of relapsing malaria?

Plasmodium vivax

Which species of malaria parasite is the most prevalent and causes the majority of severe malaria cases and deaths?

Plasmodium falciparum

Who are among the most at-risk groups for severe malaria?

Pregnant women in their second and third trimesters and children aged five and under

How many species of malaria parasites cause significant disease in humans?

<p>Five</p> Signup and view all the answers

Which species of malaria parasite can result in severe malaria but with less frequency compared to others?

<p>Plasmodium vivax and Plasmodium knowlesi</p> Signup and view all the answers

What is the typical cause of severe malaria?

<p>P. falciparum infection</p> Signup and view all the answers

What are the three stages of the life cycle of malaria parasites that infect humans?

<p>Infection of a human with sporozoites, asexual reproduction, sexual reproduction</p> Signup and view all the answers

What is the infective stage of malaria parasites that infect humans?

<p>Sporozoites</p> Signup and view all the answers

What is the term for dormant sporozoites in the liver of humans infected with P.vivax and P.ovale?

<p>Hypnozoites</p> Signup and view all the answers

In which species of Plasmodium are schizonts rarely seen in peripheral blood?

<p>Plasmodium falciparum</p> Signup and view all the answers

How many merozoites can a mature schizont of Plasmodium contain?

<p>8-24</p> Signup and view all the answers

Which phase of the Plasmodium life cycle is not pathogenic and does not produce symptoms of the disease?

<p>Exoerythrocytic phase</p> Signup and view all the answers

What is the name of the process in which schizont divides asexually to form daughter cells in protozoans?

<p>Schizogony</p> Signup and view all the answers

How do sporozoites enter the bloodstream of humans?

<p>Through the bite of an infected female Anopheles mosquito</p> Signup and view all the answers

What is the term used to describe the process where sporozoites undergo asexual replication in liver cells to form a liver schizont?

<p>Exo-erythrocytic schizogony</p> Signup and view all the answers

What is the term used to describe the stage where trophozoites undergo asexual reproduction inside erythrocytes?

<p>Erythrocytic schizogony</p> Signup and view all the answers

What is the critical stage of development for the parasite to undergo morphological changes and grow in size?

<p>Ring stage trophozoites</p> Signup and view all the answers

Which stage of the parasite is responsible for the clinical manifestations of the disease?

<p>Blood stage parasites</p> Signup and view all the answers

What stage of the Plasmodium life cycle involves sporozoites staying dormant in the liver and potentially causing relapses?

<p>Hypnozoit stage</p> Signup and view all the answers

In which organism does the completion of sexual reproduction stage of the Plasmodium life cycle occur?

<p>Mosquito</p> Signup and view all the answers

What is the term used to describe the stage of Plasmodium that is rarely seen in peripheral blood of Plasmodium falciparum infections?

<p>Schizonts</p> Signup and view all the answers

How many merozoites can a mature schizont of Plasmodium contain?

<p>8-24</p> Signup and view all the answers

What is the term for the infective stage of malaria parasites that infect humans?

<p>Sporozoites</p> Signup and view all the answers

Which phase of the Plasmodium life cycle is non-pathogenic and does not produce symptoms of the disease?

<p>Exoerythrocytic phase</p> Signup and view all the answers

What are the two main causes of relapsing malaria?

<p>Plasmodium vivax and Plasmodium knowlesi</p> Signup and view all the answers

Who are the most at-risk groups for severe malaria?

<p>Pregnant women in their second and third trimesters, children aged five and under</p> Signup and view all the answers

Which Plasmodium parasite causes the majority of severe malaria cases and deaths?

<p>Plasmodium falciparum</p> Signup and view all the answers

What is the typical cause of severe malaria?

<p>Inefficacious, delayed, or absent treatment of uncomplicated malaria</p> Signup and view all the answers

How many species of malaria parasites cause significant disease in humans?

<p>Five</p> Signup and view all the answers

What is the main route through which malaria is spread to humans?

<p>Bites of infected female Anopheles mosquitoes</p> Signup and view all the answers

What is the term for the stage in which trophozoites mature into schizonts and release merozoites?

<p>Erythrocytic schizogony</p> Signup and view all the answers

Explain the significance of the ring stage trophozoites in the life cycle of malaria parasites.

<p>The ring stage trophozoites are critical for the parasite to undergo morphological changes, grow in size, and remodel the host red blood cell (RBC) to release new infectious merozoite forms into circulation.</p> Signup and view all the answers

Describe the process by which sporozoites enter the bloodstream of humans.

<p>Sporozoites enter the bloodstream of humans through the bite of an infected female Anopheles mosquito.</p> Signup and view all the answers

What is the term for the differentiation of some parasites into sexual erythrocytic stages?

<p>Gametocytes</p> Signup and view all the answers

Explain the term 'exo-erythrocytic schizogony' in the context of malaria parasite development.

<p>Exo-erythrocytic schizogony refers to the asexual replication cycle of sporozoites in liver cells, resulting in a liver schizont containing thousands of merozoites.</p> Signup and view all the answers

What is the main function of blood stage parasites in the life cycle of malaria?

<p>Blood stage parasites are responsible for the clinical manifestations of the disease.</p> Signup and view all the answers

What is the main transmission route for Giardia lamblia?

<p>Consumption of inadequately treated contaminated water, ingestion of contaminated uncooked vegetables or fruits, or person-to-person spread by the faeco-oral route.</p> Signup and view all the answers

What is the resistant stage of Giardia lamblia to chlorine in water treatment facilities?

<p>Cyst stage</p> Signup and view all the answers

Describe the infective stage of Trichomonas vaginalis.

<p>Quiescent form of the trophozoite</p> Signup and view all the answers

How is Trichomonas vaginalis primarily transmitted?

<p>By sexual intercourse</p> Signup and view all the answers

What are the key features of Trichomonas vaginalis?

<p>Trophozoite form, pear-shaped organism, central nucleus, four anterior flagella, one posterior flagellum, undulating membrane extending about two-thirds of its length.</p> Signup and view all the answers

What are the common locations where Giardia lamblia is particularly common?

<p>Tropics and subtropics</p> Signup and view all the answers

What is the characteristic shape of Balantidium coli cyst?

<p>Oval, pointed at the anterior end</p> Signup and view all the answers

Describe the shape of Balantidium coli trophozoite.

<p>Oval shape</p> Signup and view all the answers

What is the motility of Balantidium coli trophozoite?

<p>Motile</p> Signup and view all the answers

Where is Balantidium coli often found in infected individuals?

<p>Found in feces</p> Signup and view all the answers

What is the main reservoir for Balantidium coli infections?

<p>Swine and monkeys</p> Signup and view all the answers

How are Balantidium coli infections transmitted?

<p>Faeco-oral route</p> Signup and view all the answers

Describe the locomotion mechanism of flagellates.

<p>Flagellates move by lashing a tail-like appendage called a flagellum or flagella.</p> Signup and view all the answers

What is the unique characteristic of Giardia lamblia trophozoite?

<p>Bilaterally symmetrical, pear-shaped, with two nuclei (large central karyosome) and four pairs of flagella.</p> Signup and view all the answers

Explain the process of excystation in Giardia lamblia life cycle.

<p>During excystation, each cyst of Giardia lamblia gives rise to two trophozoites in the intestinal tract.</p> Signup and view all the answers

What is the role of gastric acid in the infection process of Giardia lamblia?

<p>Gastric acid stimulates excystation, leading to the release of trophozoites in the duodenum and jejunum.</p> Signup and view all the answers

How do Giardia lamblia trophozoites feed once attached to the intestinal villi?

<p>Giardia lamblia trophozoites feed on mucous secretions without penetrating the mucosa lining.</p> Signup and view all the answers

What is the structure of a Giardia lamblia cyst and how does it contribute to transmission?

<p>The oval-shaped cyst has a thick smooth wall, four nuclei, and contains parabasal bodies and flagella. Each cyst gives rise to two trophozoites during excystation in the intestinal tract.</p> Signup and view all the answers

Where is the trophozoite of Trichomonas vaginalis found in women?

<p>Urethra &amp; vagina</p> Signup and view all the answers

What is the primary mode of transmission for Trichomonas vaginalis?

<p>Sexual intercourse</p> Signup and view all the answers

What is the prevalence of Trichomonas vaginalis in developing countries among women?

<p>5% –20%</p> Signup and view all the answers

Where can T.vaginalis be found in females for laboratory diagnosis?

<p>Urine sediment, wet preparations of vaginal secretions, vaginal scrapings</p> Signup and view all the answers

How can infections of Trichomonas vaginalis occasionally be transmitted other than through sexual intercourse?

<p>Fomites (toilet articles, clothing)</p> Signup and view all the answers

In which tissues do large numbers of trophozoites in the tissues and secretions of men result in inflammation?

<p>Urethra &amp; prostate gland</p> Signup and view all the answers

Where can Trichomonas vaginalis trophozoite be found in women?

<p>Urethra and vagina</p> Signup and view all the answers

What is the primary mode of transmission for Trichomonas vaginalis?

<p>Sexual intercourse</p> Signup and view all the answers

What is the prevalence of Trichomonas vaginalis in developing countries among women?

<p>5% – 20%</p> Signup and view all the answers

How can infections of Trichomonas vaginalis occasionally be transmitted other than through sexual intercourse?

<p>By passage through the mother's infected birth canal</p> Signup and view all the answers

Where can Trichomonas vaginalis trophozoite be found in men?

<p>Urethra and prostate gland</p> Signup and view all the answers

What are the reported prevalence rates of Trichomonas vaginalis in developing countries among men?

<p>2% – 10%</p> Signup and view all the answers

What is the main route of transmission for Giardia lamblia?

<p>Consumption of inadequately treated contaminated water, ingestion of contaminated uncooked vegetables or fruits, or person-to-person spread by the faeco-oral route.</p> Signup and view all the answers

How can laboratory diagnosis of Giardia lamblia be confirmed in asymptomatic carriers?

<p>Examination of formed stool showing cysts.</p> Signup and view all the answers

What is the infective stage of Trichomonas vaginalis?

<p>Trophozoite.</p> Signup and view all the answers

What is the critical method for the detection of parasitic antigens in Giardia lamblia?

<p>Immunologic tests.</p> Signup and view all the answers

How is Trichomonas vaginalis primarily transmitted?

<p>Sexual intercourse.</p> Signup and view all the answers

Where is Giardia lamblia particularly common?

<p>Tropics and subtropics.</p> Signup and view all the answers

Describe the locomotion mechanism of flagellates.

<p>Flagellates move by lashing a tail-like appendage called a flagellum or flagella.</p> Signup and view all the answers

Explain the process of excystation in Giardia lamblia life cycle.

<p>Excystation in Giardia lamblia life cycle is stimulated by gastric acid, leading to the release of trophozoites in the duodenum and jejunum.</p> Signup and view all the answers

What is the unique characteristic of Giardia lamblia trophozoite?

<p>The Giardia lamblia trophozoite has a bilaterally symmetrical, pear-shaped body with two nuclei and four pairs of flagella.</p> Signup and view all the answers

Describe the shape of Balantidium coli trophozoite.

<p>The Balantidium coli trophozoite is oval in shape.</p> Signup and view all the answers

What is the infective stage of malaria parasites that infect humans?

<p>The infective stage of malaria parasites that infect humans is the sporozoite.</p> Signup and view all the answers

Describe the shape of Balantidium coli trophozoite.

<p>Oval shape</p> Signup and view all the answers

What is the main transmission route for Balantidium coli infections?

<p>Fecal-oral route</p> Signup and view all the answers

Describe the infective stage of Trichomonas vaginalis.

<p>The infective stage of Trichomonas vaginalis is the trophozoite.</p> Signup and view all the answers

Explain the life cycle of Balantidium coli.

<p>Involves ingestion of infectious cysts, excystation, and invasion of trophozoites into the mucosal lining of the large intestine, caecum, and terminal ileum.</p> Signup and view all the answers

What is the epidemiological significance of Balantidium coli infections?

<p>Distributed worldwide, with swine and monkeys as important reservoirs; transmission through fecal contamination of water supplies.</p> Signup and view all the answers

How does Balantidium coli cyst differ from the trophozoite in terms of motility?

<p>Cyst is non-motile, while trophozoite is motile.</p> Signup and view all the answers

What is the pathological similarity between Balantidium coli and amebiasis?

<p>Both organisms elaborate proteolytic and cytotoxic substances that mediate tissue invasion and intestinal ulceration.</p> Signup and view all the answers

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