What is the vector for Babesia species that infect humans?

• A. Fleas
• B. Lice
• C. Ticks
• D. Mosquitoes

Answer: (C)

The main idea is that Babesia infections in humans come from tick bites. Babesia are intraerythrocytic protozoa, and the parasite is transmitted to people by Ixodid (hard) ticks during feeding. In North America, the common culprits are Ixodes scapularis (deer tick), and in Europe Ixodes ricinus, among others. The tick acquires Babesia as it feeds on an infected animal, and the parasite can be transmitted through the tick’s saliva when it bites a human, often after the tick has attached for a while. That makes ticks the natural vector for babesiosis.

Fleas, lice, and mosquitoes transmit other pathogens but not Babesia; understanding the specific vector helps explain why babesiosis cases often cluster where tick exposure occurs, especially in wooded or grassy areas.