Introduction:
Poxviruses comprise a family of genetically related, large, enveloped, DNA viruses that replicate exclusively within the cytoplasm of vertebrate or invertebrate cells. DNA viruses typically replicate and express their genomes in the nucleus making extensive use of cellular proteins. In contrast, poxviruses rely heavily on virus-encoded proteins enabling them to replicate in the cytoplasm.
The most intensively studied poxviruses belong to the Orthopoxvirusgenus, including variola virus (causative agent of smallpox, eradicated from nature), vaccinia virus(VACV; the modern smallpox vaccine, now endemic in Brazil), cowpox virus (the original smallpoxvaccine, indigenous in Europe, occasionally infects humans) and monkeypox virus (indigenous inAfrica, causes a smallpox-like disease of humans). Studies of VACV have provided most of what weknow about poxvirus entry
Variola:
Variola caused worldwide epidemics. It has been eradicated, although US and Russian laboratories and perhaps others have stocks. 2-10 days post infection, one develops chills, myalgia and fever and then a few days later hemorrhagic vesicles on head and extremities. Immunity is lifelong. Treatment is as with CMV; cidofovir.
Monkey-Pox: see viruses