Which virus listed is an arbovirus within the Togavirus family?

• A. Western equine encephalitis virus
• B. Rubella virus
• C. Chikungunya virus
• D. Zika virus

Answer: (C)

Arboviruses are viruses transmitted to humans by arthropod vectors, most commonly mosquitoes. The Togavirus family includes several enveloped, positive-sense RNA viruses, and within this family the Alphavirus genus contains multiple arboviruses that can infect people.

Chikungunya virus fits both parts of the clue: it is in the Togavirus family and it is transmitted by mosquitoes, making it an arbovirus. Rubella virus, while also a Togavirus, is spread by respiratory droplets rather than by arthropod vectors, so it isn’t an arbovirus. Zika virus is an arbovirus, but it belongs to the Flavivirus genus, not Togavirus. Western equine encephalitis virus is another Togavirus that is arboviral, but from the list the familiar and exam-focused example of a Togavirus arbovirus is chikungunya.