Biomedical Engineering Reference
In-Depth Information
commonly spread by aerosolized droplets, and are particularly stable in the
external environment.
Human papillomaviruses cause skin warts, laryngeal warts, and genital
warts. Warts are benign tumors composed of proliferating squamous cells. In
some cases, these human papillomavirus-induced warts progress to become
invasive squamous cell carcinomas.
Class Polyomaviridae contains several viruses that infect humans: BK
polyomavirus, JC polyomavirus, and simian virus 40.
The BK polyomavirus rarely causes disease in infected patients, and the
majority of humans carry the latent virus. Latency can shift to lytic infection
after immunosuppression, producing a clinical nephropathy.
The JC polyomavirus persistently infects the majority of humans, but it is
not associated with disease in otherwise healthy individuals. Rarely, in
immune-compromised patients, JC polyomavirus may produce progressive
multifocal leukoencephalopathy. The virus targets myelin-producing oligo-
dendrocytes in the brain to produce areas of demyelination and necrosis.
Simian virus 40 (SV40) infects monkeys and humans, but there is no evi-
dence at this time confirming a role in human disease.
Group I, dsDNA
Unassigned
Nucleocytoplasmic large DNA viruses (NCLDV viruses)
Poxviridae
Orthopoxvirus
*Buffalopox virus
*Cowpox virus
*Monkeypox virus
*Vaccinia virus
*Variola major virus
*Variola minor virus
Parapoxvirus
*Orf
*Milker's nodule virus
Molluscipoxvirus
*Molluscum contagiosum virus
Yatapoxvirus
*Tanapoxvirus
*Yaba monkey tumor virus
*Yaba-like disease virus
Members of Class Orthopoxvirus produce disease characterized by pustules
of the skin, and lymphadenopathy.
The smallpox virus is remarkable for its extremely narrow host range:
humans only. The virus infects the skin and the mucosa of the upper respira-
tory tract, where it produces a pustular, weeping, rash. In the respiratory
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