Table of Contents
Plasmodium vivax
Plasmodium viridax, a protozoal parasite, is a human pathogen. This parasite is the most common and widespread cause of recurring malaria. P. viridax malaria can cause severe illness and death. It is more virulent than Plasmodium falciparum (the most deadly of the five human malaria parasites), but it can be fatal. P. viritax is transmitted by the female Anopheles mosquito. The males don’t bite.
Plasmodium falciparum
Plasmodium falciparum, a protozoan parasite that infects humans unicellularly, is the most deadly form of Plasmodium. It is transmitted by the bite of female Anopheles mosquitoes and causes falciparum malaria, the most severe form of the disease. It accounts for approximately 50% of all cases. P. falciparum has been described as the most deadly parasite known to man. It is also linked to the development of blood cancer (Burkitt’s lymphoma).
This species was created from Laverania, a malarial parasite that was found in gorillas around 10,000 years ago. Alphonse Leveran, who first identified the parasite in 1880 and gave it the name Oscillaria malariae, was the first person to do so. It was transmitted by mosquitoes in 1897 by Ronald Ross. Giovanni Battista Grassi discovered the transmission of this parasite from a female anopheline moth to humans in 1898. Plasmodium falciparum was first named by William H. Welch in 1897. The name was officially adopted by ICZN in 1954. P. falciparum can take many forms throughout its life cycle. The sporozoites, which are produced by the salivary glands of mosquitoes, are responsible for infecting humans. The sporozoites are able to grow and multiply in the liver, becoming merozoites. These merozoites infiltrate the erythrocytes to form trophozoites (RBCs), schizonts, and gametocytes. This is when the symptoms of malaria are formed. The gametocytes in the mosquito undergo sexual reproduction to become a zygote. Ookinete is responsible for the formation of sporozoites from oocytes.
According to the World Health Organization World Malaria Report 2020 there were 229,000,000 cases of malaria in 2019 worldwide, resulting in approximately 409,000 deaths. P. falciparum is responsible for nearly all deaths from malaria. 94% of these cases are in Africa. 67% of all deaths are caused by P. falciparum in children under five years old. Nearly 100% of the cases in Sub-Saharan Africa were caused by P. falciparum. In most other countries with malaria, other less virulent species are more common.
Differences between Plasmodium vivax and Plasmodium falciparum – Plasmodium vivax vs Plasmodium falciparum
| Character | Plasmodium vivax | Plasmodium falciparum |
| Diseases | Benign tertian malaria | Malignant tertian malaria |
| Geographical area | Tropics, Africa (rarely found in West Africa), Middle East Asia, Central America, and Central America. It is the most widespread species of Plasmodium that causes malaria in humans. | Predominant species worldwide tropics, especially sub-Saharan Africa. |
| Type of RBC invaded | Primarily, reticulocytes and young red cells are invaded. | All red cells are infected regardless of age. |
| Parasitized red cell lines | Enlarged, pale. Fine stippling (Schuffner dots). | Not enlarged. Coarse stippling, (Maurer’s clefts). |
| Color of the cytoplasm (in Giemsa stained thick blood smear). | Decolorized, pale. | Sometimes, normal, bluish tinge |
| Maximum parasitemia level | Blood can be up to 30,000/mL | May exceed 200,000/mLUsually, 50,000/mL |
| No. No. | 30,000 | 10,000 |
| Ring stagetrophozoites | Large rings (3-1/2 inches in diameter) One chromatin granule is usually used; the ring is delicate. | Small rings (1/5 of a red cell’s diameter). Two granules are common; multiple infections can occur; the ring may stick to red cells. |
| Pigment in developing trophozoites | Fine; light brown; scattered | Black; coarse; no clumps |
| Late Trophozoite | Medium SizedRarely amoeboidVacuole inconspicuous. | LargeAmoeboid in a major wayVacuole prominent. |
| Late trophozoite shape | Very pleomorphic | It is compact and well-rounded |
| Schizont | Small, compact,One pigmented massSeldom found in peripheral blood smear | Large, amoeboid,Pigments in coarseIt can be seen in the blood-smear |
| Mature schizonts (segmenters) | More than 12 merozoites (14-24). | More than 12 merozoites (8-32). Rare in peripheral blood. |
| Gametocytes | Oval or round | Crescentic |
| Microgametocytes | Kidney-shaped with blunt, round ends.Cytoplasm stains pale blue.Nucleus large.Chromatin diffuse.Fine, dispersed granules | Spherical, compact.Cytoplasm stains pale light blue.Chromatin univided.Granules abundant. |
| Macrogametocytes | Crescentic.Cytoplasm stains dark blue.Nucleus compact.Central ChromatinPigment is more compact | Spherical.Cytoplasm stains dark blue.Nucleus small.Pigment diffuse ecoarse. |
| Distribution in peripheral blood | All forms | Only rings (gametocytes) and crescents (gametocytes) are allowed. |
| The duration of the asexual phase in men | 36-48 hoursUsually, 48 hours | 48 hours |
| The duration of sporogony by mosquito | 22-23 days at 20degC10- 12 days at 27degC | 30 Days at 17.5degC10 days at 25-30degC |
| Time of intrahepatic phase | 5.5 Days | 8 days |
| The duration of Schizogony | 12 days | 14 days |
| Mechanism of Attachment and Receptor | Merozoite (non-complement-mediated attachment), Duffy antigen | Glyphophorin A, B and Merozoite |
| Pigment Color | Black and dark brown | Yellow or Golden Brown |
| Incubation period | The incubation period is usually between 10 and 17 days | The shortest of all the plasmodia. It can be between 7 and 10 days long, but does not last for months or years. |
| Signs and Symptoms | The patient experiences flu-like symptoms, including headaches, muscle pains and nausea. | P. P. The frequency of the attacks becomes tertian (36-48 hours), and fulminating diseases develop. |
| Symptom periodicity | 48 hours | 36-48 hours |
| Complications | P. is not known to have severe complications. Although vivax infections are rare, coma and sudden deaths or other symptoms indicative of cerebral involvement have been reported. | Circulatory collapse, cerebral malaria, severe anemia and hemoglobinuria are all possible. Acute cerebral malaria can cause mental changes that may lead to death within three days if left untreated. |
| Anemia | Moderate to mild | Severe |
| CNS involvement | Rare | Very common |
| Nephrotic syndrome | Possible | Rare |
| Disease symptoms | P. P. | P. P. |
| Infection severity | Comparatively, less severe infections | Plasmodium parasites are considered the most dangerous and deadly. |
| Mortality and morbidity | Relatively lower | Higher |
| Prevalence | This is the most common of all human plasmodia. | Comparatively, it is less common. |
| Diagnosis | Thin and thick blood smears, ring stage in RBCs featuring Schuffner dots | Thin and thick blood smears, banana-shaped gametocytes, double rings in RBCs |
| The main diagnostic criteria | Large, pale-colored cells; trophozoite irregular. Pigment usually present. Schuffner’s dots sometimes not always present. Multiple phases of growth can be seen in one smear. Gametocytes may appear as early as the third day. | The development of the ring stage occurs in blood vessels of internal organs. |
| Treatment | Chloroquine (where there is no resistance), mefloquine, atovaquone/proguanil, or both. | Chloroquine (where no resistance); quinine sulfate plus doxycycline or plus tetracycline or plus clindamycin; atovaquone/ proguanil, mefloquine, bartesunate plus doxycycline or clindamycin; artemether/ lumefantrine (coartem). |
| Untreated infection can last for a long time | 5-7 Years | 6-17 Months |
| Relapse | Hypnozoites in the liver can cause a relapse | There is no relapse |
| These are the distinguishing characteristics summarized | 1. 48-hour cycle2. Infects young cells3. RBCs with larger dimensions4. After 8-10 hours, Schuffner’s dots (true tipping)5. Delicate ring6. A very ameboid trophyozoite7. Mature schizont contains 12-24 merozoites | 1. Cycle duration: 36-48 hours2. Infects any cell, regardless of age. Very severe infections may occur.3. RBCs of all sizes4. No Schuffner’s dots. (Maurer’s dots): May be larger, single dots.5. Multiple rings/cell (only gametocytes and young rings are visible in peripheral blood).6. Delicate rings may contain two dots of chromatin/ring/applice or accole forms7. Gametocytes with a crescent-shaped shape |
