A traveler returns with malaria after visiting a tropical area. Analyze the likely reservoir, vector type, portal of entry, and two immediate prevention measures that should be recommended to travelers to that area.

• A. Reservoir often humans (for many malaria species), vector is a biological arthropod (Anopheles mosquito), portal of entry is the skin via mosquito bite; immediate prevention: use insecticide-treated bed nets and apply insect repellent and eliminate standing water at lodging to reduce mosquito breeding and biting.
• B. Reservoir is domestic animals that shed malaria in droppings, vector is a mechanical fly that contaminates food, portal of entry is ingestion; prevention should focus on boiling drinking water and avoiding meat consumption exclusively.
• C. Reservoirs are soil organisms, vector is airborne dust that carries spores to the lungs, portal of entry is respiratory inhalation; immediate prevention is to wear surgical masks indoors but no vector control is needed.
• D. Reservoir is local vegetation, vector is ticks that transmit malaria to humans by biting plant surfaces first then people, and prevention is to avoid touching plants and to spray vegetation with bleach daily.

Answer: (A)