Which of the following is the causative agent of a variety of cutaneous warts (plantar, common, and flat) and is associated with cervical neoplasia?
**Core Concept**
Human papillomavirus (HPV) is a DNA virus belonging to the family Papillomaviridae. It is known to infect epithelial cells, leading to various manifestations, including benign and malignant lesions. The virus has a tropism for skin and mucosal surfaces, where it causes localized infections, such as cutaneous warts, and is also associated with an increased risk of cervical neoplasia.
**Why the Correct Answer is Right**
HPV infects epithelial cells through the action of its L1 and L2 capsid proteins, which facilitate attachment and entry into the host cell. Once inside, the viral genome is released, and the E6 and E7 oncogenes of HPV are expressed, leading to the disruption of normal cell cycle regulation. In the context of cutaneous warts, HPV causes hyperplasia of the keratinocytes, resulting in the characteristic lesions. In addition, the association between HPV and cervical neoplasia is well-established, with high-risk types such as HPV-16 and HPV-18 being implicated in the development of cervical cancer.
**Why Each Wrong Option is Incorrect**
**Option B:** West Nile virus is a flavivirus transmitted primarily through the bite of infected mosquitoes, causing fever, encephalitis, and meningitis in humans. It is not associated with cutaneous warts or cervical neoplasia.
**Option C:** Tick-borne encephalitis virus is a flavivirus transmitted through the bite of infected ticks, causing encephalitis and meningitis in humans. It is not linked to cutaneous warts or cervical neoplasia.
**Option D:** Polyomavirus is a family of DNA viruses that infect a wide range of organisms, including humans. While some polyomaviruses have been associated with disease in immunocompromised individuals, they are not the causative agents of cutaneous warts or cervical neoplasia.
**Clinical Pearl / High-Yield Fact**
HPV is the most common sexually transmitted infection worldwide, and its vaccine has been shown to be highly effective in preventing cervical neoplasia and other HPV-related diseases. It is essential for healthcare providers to educate patients about the risks and benefits of HPV vaccination and to encourage its uptake, particularly in adolescents and young adults.
✓ Correct Answer: A. Human papillomavirus