What is the causative agent of Chikungunya?

• A. A rhinovirus
• B. An alphavirus
• C. A flavivirus
• D. A retrovirus

Answer: (B)

Chikungunya is caused by an alphavirus, a positive-sense, single-stranded RNA virus in the Togaviridae family. These enveloped viruses are transmitted to humans by Aedes mosquitoes (such as A. aegypti and A. albopictus), which explains the mosquito-borne spread and regional outbreaks. The other options don’t fit because rhinovirus causes the common cold, flaviviruses include dengue and Zika and are a different genus, and retroviruses (like HIV) have a different replication strategy and disease profile.