Small pox belongs to which class of poxviruses ?
**Core Concept**
Smallpox is a highly infectious and sometimes fatal infectious disease caused by the variola virus, which belongs to a specific class of poxviruses. Poxviruses are a family of large, complex viruses that replicate in the cytoplasm of infected cells and cause a range of diseases in humans and animals.
**Why the Correct Answer is Right**
The variola virus, responsible for smallpox, is classified as an orthopoxvirus. This classification is based on the virus's genetic and morphological characteristics, as well as its ability to replicate and cause disease in humans. Orthopoxviruses are a subset of poxviruses that are known to cause diseases such as cowpox, camelpox, and monkeypox, in addition to smallpox.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the correct classification of the variola virus is not a member of the chilopoxvirus or yatapoxvirus groups.
* **Option B:** This option is incorrect because the correct classification of the variola virus is not a member of the leporipoxvirus group, which includes viruses that cause diseases in rabbits and hares.
* **Option C:** This option is incorrect because the correct classification of the variola virus is not a member of the parapoxvirus group, which includes viruses that cause diseases such as warts and molluscum contagiosum.
**Clinical Pearl / High-Yield Fact**
The variola virus was declared eradicated in 1980, following a global vaccination campaign led by the World Health Organization. However, the virus remains a potential bioterrorism threat, and efforts to develop and stockpile vaccines and treatments for smallpox continue.
**Correct Answer:** C. Orthopoxvirus.