Hypnozoites are dormant forms in the life cycles of certain parasitic protozoa that belong to the Phylum Apicomplexa (Sporozoa) and are best known for their probable association with latency and relapse in human malarial infections caused by Plasmodium ovale and P. vivax.

What is Hypnozoite malaria?

Hypnozoites are dormant forms in the life cycles of certain parasitic protozoa that belong to the Phylum Apicomplexa (Sporozoa) and are best known for their probable association with latency and relapse in human malarial infections caused by Plasmodium ovale and P. vivax.

Which drug is used against Hypnozoite in malaria cycle?

Typically, primaquine is administered concurrently with chloroquine at a dose of 15 mg base per day for 14 days (210 mg total dose). In some regions such as in the Indonesia archipelago, higher doses of primaquine (30 mg base for 14 days; 420 mg total dose) are administered to prevent relapse.

Which malaria parasite has Hypnozoite stage?

Because of the population densities especially in Asia it is probably the most prevalent human malaria parasite. P. vivax (as well as P. ovale) has dormant liver stages (“hypnozoites”) that can activate and invade the blood (“relapse”) several months or years after the infecting mosquito bite.

What causes activation of hypnozoites?

Some of the sporozoites develop into hypnozoites in the human liver. It is suggested that the hypnozoite activates when it recognizes the same Anopheles specific protein, which it had previously recognized as a sporozoite to invade the salivary gland in the vector.

What are merozoites in malaria?

The invasive blood stage of malaria parasites, merozoites, are complex entities specialized for the capture and entry of red blood cells.

Where are Hypnozoites found?

To confirm that hypnozoites resided within human hepatocytes and not to remaining mouse hepatocytes, which could retard liver stage development, we used an antibody to detect human FAH in the infected liver sections. Indeed, all observed hypnozoites were located within human hepatocytes (Figure S1C).

What is gametocytes in malaria?

Gametocytes are the only form of the malaria parasite that is transmissible to the mosquito vector. They are present at low levels in blood circulation and significant knowledge gaps exist in their biology.