Some malaria species can form dormant liver-stage hypnozoites before infecting red blood cells.

• A. Toxoplasmosis
• B. Giardiasis
• C. Malaria
• D. Dengue

Answer: (C)

Dormant liver-stage forms called hypnozoites are a feature of certain malaria parasites, especially Plasmodium vivax and Plasmodium ovale. After a mosquito bite, parasites reach the liver and begin to multiply. In these species, some parasites become hypnozoites, long-lived dormant cells inside liver cells. They can stay inactive for weeks to months and later reactivate, releasing parasites that invade red blood cells and cause malaria symptoms again. This dormancy explains relapses that occur without a new mosquito bite.

Other listed infections don’t involve this liver-dormant stage: Toxoplasmosis forms latent tissue cysts in various tissues but not a hepatic hypnozoite stage; Giardiasis is an intestinal parasite with no liver dormancy; Dengue is a viral illness without dormant liver forms.