Which virus is associated with cervical dysplasia and squamous cell carcinoma?

Cervical dysplasia and squamous cell carcinoma are highly associated with Human papillomavirus (HPV), particularly certain high-risk types of HPV, such as HPV 16 and 18. This virus is known to infect the squamous epithelial cells of the cervix, leading to cellular changes that can progress to dysplasia and eventually cancer if left untreated. The mechanism involves the viral proteins E6 and E7, which interfere with the host cell's regulatory proteins, leading to unchecked cell proliferation and the potential for malignant transformation.

Understanding the role of HPV in cervical pathology has been significant in public health, especially with the development of vaccines targeting the most common oncogenic strains. This has led to a decrease in the incidence of cervical cancer in populations that have adopted routine vaccination and screening practices. Other viruses listed, such as herpes simplex virus and influenza virus, do not have a direct causal relationship with cervical dysplasia or cancer, and while HIV plays a role in immunosuppression that can facilitate the progression of various cancers, it is not independently responsible for initiating cervical dysplasia.