Malaria Transmission via Mosquito Bites

Steps:

• Recall that malaria is caused by Plasmodium parasites.
• Identify the vector: female Anopheles mosquitoes transmit the disease.
• Understand the mechanism: infected mosquitoes inject parasites during blood meals.
• Confirm transmission occurs when saliva containing parasites enters the human bloodstream.

Why D is correct:

• Malaria is defined as a vector-borne disease where Plasmodium sporozoites in mosquito saliva are injected into the bloodstream during a bite, initiating infection.

Why the others are wrong:

• A: Malaria is not contagious between people; it requires a mosquito vector.
• B: Parasites are not waterborne; transmission is exclusively mosquito-mediated.
• C: Food contamination does not transmit malaria; parasites are delivered via mosquito bites, not ingestion.

Final answer: D