Plasmodium ovale

What sample is needed for Plasmodium ovale?

1. Malarial parasites (MP) may be detected in a patient’s blood smear.
   1. The best time to make a smear is during shivering.
   2. Make thick and thin blood smears.
2. Serum is needed for serological methods and PCR.

What are the indications?

• For the diagnosis of the malarial parasite.

How will you define Plasmodium Ovale?

1. Plasmodium ovale was described in 1922.
2. Plasmodium ovale causes benign tertian malaria, with a 48-hour fever cycle.
3. It infects young RBCs, and these have fimbriated cytoplasm.
4. Untreated cases may have relapses for up to 5 years.
5. It is less severe than Plasmodium falciparum.

How will you discuss the Plasmodium ovale life history?

1. 8% of cases are in parts of Africa.
2. Few cases in Asia.
3. Plasmodium ovale represents only a small percentage of infections.
4. Plasmodium ovale is dormant in the liver, which can become active without a mosquito bite.

How will you describe the erythrocytic cycle of Plasmodium ovale?

1. Ring form is like P. vivax.
   1. The difference is that the ring is larger than in P. vivax.
   2. The ring is also thicker.
2. Trophozoites maintain their ring form.
3. The amoeboid tendency is common.

4. Schizonts consist of dividing chromatin surrounded by the cytoplasm.
   1. There are Rossetts of merozoites, 8 on average.
   2. 3/4 of the cell is occupied by the parasite.

How will you discuss the clinical presentation of Plasmodium ovale?

1. Initial symptoms are flu-like.
2. The typical paroxysm is every 48 hours.
3. Relapse may take place, and there is spontaneous recovery.
4. The above feature is not seen in P. vivax.

How will you diagnose Plasmodium ovale?

1. History of the patient in suspected areas.
2. Blood smear:
   1. Make a blood smear when the patient has a fever. Thin and Thick smears are made.
   2. A thick smear is more helpful for detecting malarial parasites.
      1. A thin smear is good for identifying the type of malarial parasite.
   3. Collect blood 6 to 8 hourly for 48 hours to declare negative for malaria.
   4. Giemsa stain is the best choice.
3. Serologic methods are based on immunochromatic techniques. Tests often use a dipstick or cassette format and provide results in 2-15 minutes.
4. Polymerase chain reaction (PCR): Parasitic nucleic acids are detected using PCR.
   1.  This is more sensitive than smear microscopy.
   2. This is of limited value for diagnosing acutely ill patients because of the time needed for this procedure.

How will you control Mosquitoes?

1. Try to eliminate breeding places:
   1. Fill the vacant land and pump out the water.
   2. Remove the junk and water-retaining debris.
2. Destroy the larvae:
   1. Clean the drains.
   2. Try to remove algae from the ponds.
   3. Add larva-eating fish to the ponds.
3. Use of insecticide:
   1. The best example is DDT.
4. Use of mosquito repellent:
   1. Pyrethroid repellent.
   2. N, N- diethyl meta tolbutamide.
5. Use of mosquito nets.
6. Use clothes to prevent mosquito bites.
7. Train people on malaria prevalence.
8. Train people in malaria detection, treatment, and follow-up.

How will you treat Plasmodium ovale?

1.  Antimalarial drugs are quinidine, chloroquine, primaquine, pyrimethamine, sulfadoxine, mefloquine, tetracyclines, and proguanil.
2. Chloroquine is the drug of choice and is best for P. falciparum.
   1. This is effective for the erythrocytic stage and not for the liver stage.
   2. Must use primaquine to eradicate P. ovale and P. vivax.
   3. There are chloroquine-resistant cases of P. falciparum.
3. Amodiaquine, piperaquine, and pyronaridine are close to chloroquine.
   1. In some areas, Amodiaquine is less toxic, cheaper, and more effective than chloroquine against chloroquine-resistant P. falciparum.
4. Mefloquine is effective against chloroquine-resistant P. falciparum.
5. Quinine and quinidine are still the first lines of therapy against P. falciparum.
6. Primaquine is a synthetic drug and is the drug of choice for eradicating the liver stage from P. vivax and P. ovale.
7. Antibiotics and Inhibitors of folate synthesis are slow-acting antimalarial drugs.
8. Halofantrine and lumefantrine are related to quinine and are effective against the erythrocytic stage.
9. Malaria drug-resistant strains are emerging.

What is the duration of the various cycles in malarial parasites?

Questions and answers:

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