Which unique property of Plasmodium makes malaria a cyclical disease with periodic fever?

Correct option is C

Correct Answer: (C) RBC rupture and toxin release every few days

Explanation:

• The cyclical fever in malaria is caused by the rupture of red blood cells (RBCs) infected by the Plasmodium parasite, which occurs in a synchronized cycle (typically every 48 or 72 hours depending on the species).
• This rupture releases toxins like hemozoin, which trigger the immune response, resulting in fever, chills, and sweating.
• This regular RBC rupture and release of toxins make malaria a cyclical disease with intermittent fever spikes.

Information Booster:

• Plasmodium vivax and Plasmodium falciparum are the most common species in India.
• P. vivax typically causes fever every 48 hours (tertian malaria).
• P. malariae causes fever every 72 hours (quartan malaria).
• The cycle starts with sporozoite entry via mosquito bite, multiplication in the liver, followed by infection of RBCs.
• The female Anopheles mosquito is the vector for malaria transmission.

Additional Information (Why other options are incorrect):

• (A) Infection of liver cells only – Liver stage is asymptomatic and doesn't cause fever; RBC stage is responsible for symptoms.
• (B) Constant reinfection from environment – Malaria is not caused by environmental reinfection; the cycle is internal after initial infection.
• (D) Continual entry via mosquito bites – Multiple bites may worsen spread, but fever periodicity is due to internal RBC rupture, not repeated bites.