ABSTRACT
The family Poxviridae comprises a large number of viruses capable of infecting insects, reptiles, birds, and mammals. Although eight genera are recognized in the subfamily of poxviruses that infect vertebrates (Chordopoxvirinae), only four contain species that infect humans. Based on their host preferences, poxviral members with potential to infect humans are divided into three types: human-specic, primate-specic, and zoonotic. The human-specic poxviruses belong to the genera Orthopoxvirus (i.e., variola virus) and Mollusipoxvirus (i.e., and molluscum contagiosum); the primate-specic poxviruses are found in the genus Yatapoxvirus (i.e., tanapox and yaba monkey tumor viruses); and the poxviruses causing zoonotic infections are in the genera Parapoxvirus [i.e., orf, bovine papular stomatitis, pseudocowpox (all of ungulates), and sealpox virus (seals)], and Orthopoxvirus (i.e., vaccinia, cowpox, and monkeypox viruses; Table 92.1) [1,2]. The devastating history of variola virus (the causative agent of smallpox) has been well documented [3] and smallpox represents the only human viral disease to be eradicated through vaccination [4,5]. In contrast, molluscum contagiosum produces a mild rash of the hands and genitals in humans that eventually resolves [2]. The remaining poxviruses that can infect humans are transmitted by insect vectors or contact with infected animals. Some cause clinically serious disease (monkeypox, cowpox virus) and at least one has been demonstrated only in volunteer infection or accidental needlestick of humans (YMTV); however, the remainder poxviruses produce self-limiting infections in immunocompetent humans [1]. Here we outline the history and characteristics of tanapox
virus (TANV), including the biological features that dene tanapox as a unique member of the family Poxviridae.
