Cladistics
Genus
Poxviridae
Chordopoxvirinae
Parapoxvirus
Orthopoxvirus
Cowpox Virus
Vaccinia Virus
Yaba Virus
Primate
Group I Viruses
Jules J. Berman, in Taxonomic Guide to Infectious Diseases, 2012
Members of Class Yatapoxvirus infect primates in equatorial Africa. Infections can spread to humans by insect vectors. Tana poxvirus produces a pock-forming skin infection, with fever and lymphadenopathy in infected humans (like a mild form of smallpox). The Yaba monkey tumor virus produces histiocytomas in monkeys. Histiocytomas are proliferative lesions of fibrous tissue that yield tumor-like nodules. These virally induced histiocytomas in monkeys grow rapidly following infection, and then regress over the ensuing month [127]. Yaba monkey tumor virus and Yaba-like disease virus, like all members of Class Yatapoxvirus, are considered potential human pathogens.
Group I, dsDNA
Unassigned
Nucleocytoplasmic large DNA viruses (NCLDV viruses)
Mimiviridae
Mimivirus
*Acanthamoeba polyphaga mimivirus (pneumonia)
Yatapoxviruses
J.W. Barrett, G. McFadden, in Encyclopedia of Virology (Third Edition), 2008
The genus Yatapoxvirus includes two members: yaba monkey tumor virus (YMTV), the type species, and tanapox virus (TPV). These viruses are primate specific and of African origin. YMTV infects monkeys naturally and humans only by accident or injection. TPV infects humans, and a strain of TPV, called yaba-like disease virus (YLDV), has been isolated from primates and their handlers in primate centers. The genomes of the known Yatapoxvirus members have all been sequenced and are among the smallest poxvirus genomes known: 134.7 kbp (YMTV) and 144.6 kbp (TPV/YLDV). YMTV and TPV share the genomic features of other poxviruses, including terminal inverted repeats at the ends of their linear double-stranded genomes and an A+T-rich (70–73%) sequence. YMTV infection of rhesus monkeys produces subcutaneous tumors that are composed of histiocytes, which actively divide and become spindle shaped. These large histiocytomas naturally regress over several months. TPV infection involves a short febrile illness followed by the appearance and development of individual, hard, raised nodules that regress after 3–4 weeks. Transmission of the yatapoxviruses is most likely via bite from an arthropod vector (mosquito), but their reservoir host species remains unknown.
Other Poxviruses That Infect Humans
Brett W. Petersen, Inger K. Damon, in Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases (Eighth Edition), 2015
Definition•
Parapoxviruses, molluscum contagiosum, and yatapoxviruses are among the nonorthopoxvirus infections of humans.
Epidemiology•
Parapoxvirus infections most commonly occur in individuals with occupational exposures to infected sheep, cattle, or goats.•
Molluscum contagiosum infection occurs worldwide and is spread through mild skin trauma, fomites, and sexual transmission.•
Yatapoxvirus infections are rarely reported; infections are acquired through exposure to infected animals and potentially arthropod vectors and are usually geographically restricted to Central and East Africa.
Microbiology•
Poxviruses are a diverse group of large, complex double-stranded DNA viruses that replicate in the cytoplasm of the host cell.
Poxvirus Infections
Caroline Weekes, ... Lakshmi P. Kotra, in xPharm: The Comprehensive Pharmacology Reference, 2007
Etiology
The genera Molluscipoxvirus, Parapoxvirus, Orthopoxvirus, and Yatapoxvirus are responsible for human infections. Molluscum. contagiosum infection causes molluscum contagiosum disease, which is generally seen only in humans. Transmission is by direct contact with infected persons or through contaminated fomites Hanson and Diven (2003). The parapoxviruses cause occupational infections or farmyard pox Mark and Bullen (1999). Orf virus affects sheep, goats, and humans. Human infection results in the disease orf. Transmission is by direct contact with animals that have infections around the mouth, nose, and eyes, or by fomites. The infection is usually acquired through abrasion sites on the hands Friedman (1994). Pseudocowpox virus causes Milkers′ nodules. It is usually acquired through contact with lesions on the teats of cows. Bovine papular stomatitis virus causes localized skin lesions Mark and Bullen (1999). In this case, infection is acquired by contact with lesions on the mouth, tongue, lips, or nares of cattle Mark and Bullen (1999). Four species of the Orthopoxvirus genus infect humans. The monkeypox virus is the etiological agent of monkeypox, which can be acquired from an infected animal, such as a squirrel or monkey, through bites, direct contact with its blood, body fluids, or lesions (www.cdc.gov). Person to person transmission is inefficient. The virus can enter through the upper respiratory tract after being released in oropharyngeal secretions by individuals with a rash Mark and Bullen (1999). Cowpox virus, the agent of cowpox, is acquired through direct contact with diseased, domesticated cats through minor abrasions. Cats get the infection from rodents, the natural reservoir hosts of this virus Lewis-Jones (2002). The variola virus, which causes smallpox, is transmitted from human to human, usually through direct and prolonged face-to-face contact, infected fluids, or contaminated items (www.cdc.gov). Human exposure to vaccinia virus, which causes buffalopox, is generally limited to laboratory workers Breman and Henderson (2002), Diven (2001).
The Double Stranded DNA Viruses
CONTRIBUTED BY, ... D. Raoult, in Virus Taxonomy, 2005
SUBFAMILY CHORDOPOXVIRINAE
TAXONOMIC STRUCTURE OF THE SUBFAMILY
| Subfamily | Chordopoxvirinae |
| Genus | Orthopoxvirus |
| Genus | Parapoxvirus |
| Genus | Avipoxvirus |
| Genus | Capripoxvirus |
| Genus | Leporipoxvirus |
| Genus | Suipoxvirus |
| Genus | Molluscipoxvirus |
| Genus | Yatapoxvirus |
DISTINGUISHING FEATURES
Includes brick-shaped or ovoid poxviruses of vertebrates with a low G+C content (30–40%), except for the parapoxviruses (64%) and MOCV (63%). Extensive serologic crossreaction and cross-protection is observed within genera, this is less obvious among the avipoxviruses. A common, conserved co-linear signature core of genes within genera (and in the case of mammalian viruses, spanning genera) is generally maintained with most divergence amongst members occurring at the terminal extremes of the genome. The co-linear signature of core genes appears different for mammalian, avian and insect poxvirus genera. Some viruses produce pocks on the chorioallantoic membranes of embryonated chicken eggs.
Neurovirology
Philip E. Pellett, ... Thomas C. Holland, in Handbook of Clinical Neurology, 2014
Poxviruses
The poxvirus family (Poxviridae) contains two subfamilies (Chordopoxvirinae and Entomopoxvirinae). Poxviruses that naturally infect humans are chordoxpoxviruses that belong to the Orthopoxvirus, Molluscipoxvirus, Parapoxvirus, and Yatapoxvirus genera. Although best known for producing characteristic skin lesions, with respect to the nervous system, the most significant poxviruses are variola virus (eradicated from the wild), vaccinia virus, and monkeypox virus (all of genus Orthopoxvirus), and molluscum contagiosum virus (genus Molluscipoxvirus).
Poxvirus virions are large and complex (Fig. 2.1). They can be brick-shaped or ovoid, with lengths of 220–450 nm and widths and thicknesses of 140–260 nm. The virus genome has a condensed nucleoprotein structure in the core. In infectious intracellular mature virions, the core is surrounded by proteinaceous lateral bodies and an envelope containing non-glycosylated virus-encoded membrane proteins. Extracellular enveloped virions have a second envelope. Poxvirus genomes range in length from 135 to 375 kb of linear dsDNA and have hairpin structures at the genomic termini such that, if denatured, the genome becomes a single-stranded circle with a circumference double the genome length. Poxviruses encode ~ 200 proteins, which are expressed from unspliced transcripts that can be coded on either strand of the genome.
Poxvirus replication takes place in the cytoplasm, which is unusual among DNA viruses, and necessitates the use of a virus-encoded RNA polymerase. Virus entry is via endocytosis (Fig. 2.2, path A2) (Moss, 2012; Schmidt et al., 2012), followed by expression of early genes, some of which play roles in modulating host defenses, while others initiate subsequent steps of replication, which includes genome replication and expression of viral intermediate genes. Intermediate genes enable expression of late genes, whose translation products include virion proteins. Virion assembly takes place in specialized factories that form on cellular membranes near the nucleus. After proteolytic release of spherical immature virions from viral factories, the particles acquire their mature morphology; these virions are released by cell lysis. Some mature virions subsequently acquire a second envelope and are released by an exocytic process (Fig. 2.5, path 6).
Neurologic disease caused by poxvirus infections includes headaches that sometimes accompany the prodromal phase of infection with monkeypox virus and tanapox virus (Damon, 2011), and rare but severe encephalitis following primary vaccination with vaccinia virus (Moss, 2011). The frequency of postvaccination encephalomyelitis(PVEM) is dependent on the vaccinia strain used as the vaccine, with the strain used in the United States (New York Board of Health) being associated with relatively low PVEM incidence. PVEM develops 11–15 days after vaccination in adults and after 6–10 days in infants under 2 years of age, with symptoms consistent with demyelinating encephalomyelitis or direct infection of the CNS. CSF pressure can be elevated but cell counts and chemistry may be normal. Specific diagnosis is difficult, and vaccinia immune globulin has no proven value. The efficacy of newer antivirals (ST-246 and CMX001) is being evaluated; these drugs were used under emergency investigational new drug protocols to treat a patient with progressive vaccinia (Lederman et al., 2012).
https://www.sciencedirect.com/topics/immunology-and-microbiology/yatapoxvirus
use up petersen and smith diseases at USA-NAC;with syphillus or rabbis (raybs and rabys and rabes and rabies and rables).
No comments:
Post a Comment