How does the smallpox virus replicate?

Upon invasion of a host cell, the smallpox virus replicates in the host cytoplasm, rather than the host nucleus, using many of the host’s own enzymes to replicate.. Replication begins once the virion has reached the cytoplasm of the host cell..

Where do pox viruses replicate?

Poxviruses are large, enveloped viruses that replicate in the cytoplasm and encode proteins for DNA replication and gene expression.

What are the steps of viral replication?

Despite this, there are generally six broad steps required for viral replication to occur successfully. These include attachment, penetration, uncoating, replication, assembly, and virion release. The first stage, attachment, involves viral proteins binding to the host cell surface.

Do pox viruses replicate in the nucleus?

Poxviruses, a family of large DNA viruses, are unique among DNA viruses, because they carry out DNA replication in the cytoplasm rather than the nucleus.

Where in the host does the smallpox virus initially replicate?

Smallpox is a double-stranded, 135- to 375-kilobase (kb) DNA virus that replicates in the cytoplasm of the host cell and forms B-type inclusion bodies (Guarnieri bodies). This is in contrast to herpes viruses, which replicate in the nucleus. The orthopoxviruses are among the largest and most complex of all viruses.

What type of virus is smallpox?

Smallpox was caused by infection with Variola virus, which belongs to the family Poxviridae, subfamily Chordopoxvirinae, and genus Orthopoxvirus.

Is smallpox DNA or RNA?

Smallpox is a double-stranded, 135- to 375-kilobase (kb) DNA virus that replicates in the cytoplasm of the host cell and forms B-type inclusion bodies (Guarnieri bodies).

What are the two types of viral replication?

There are two processes used by viruses to replicate: the lytic cycle and lysogenic cycle. Some viruses reproduce using both methods, while others only use the lytic cycle. In the lytic cycle, the virus attaches to the host cell and injects its DNA.

How do viruses replicate their DNA?

DNA viruses replicate their genomes using DNA polymerase enzymes and transcribe their mRNA using DNA-dependent RNA polymerase enzymes. Both (+) and (−) ssRNA viruses replicate and transcribe their genomes using RdRp enzymes (Fig.

How do adenoviruses replicate?

Adenoviruses possess a linear dsDNA genome and are able to replicate in the nucleus of vertebrate cells using the host’s replication machinery. Entry of adenoviruses into the host cell involves two sets of interactions between the virus and the host cell. Most of the action occurs at the vertices.

What is the pathogenesis of smallpox?

Pathogenesis. Smallpox is transmitted to the host via infection by the variola virus [3]. The point of entry for the injection typically resides in the respiratory mucosa although the virus may enter through the skin [3]. Upon infection the virus rapidly advances to the nearby lymph nodes.

How does smallpox virus work?

The virus which causes smallpox is contagious and spreads through person-to- person contact and saliva droplets in an infected person’s breath. It has an incubation period of between 7 and 17 days after exposure and only becomes infectious once the fever develops. A distinctive rash appears two to three days later.

What is the incubation period of smallpox?

Incubation period..  Incubation Period (Duration: 7 to 17 days) Not contagious  Initial Symptoms (Prodrome) (Duration: 2 to 4 days) Sometimes contagious* 7.  Smallpox may be contagious during the prodrome phase,  most infectious during the first 7 to 10 days following rash onset.

What is the best way to prevent smallpox?

PREVENTION • The smallpox vaccine is the only known way to prevent smallpox in an exposed person. The smallpox vaccine helps the body develop immunity to smallpox.

How many genes are there in the poxvirus genome?

Several poxvirus genomes have been sequenced. Most of the essential genes are located in the central part of the genome, whereas non-essential (in tissue culture) genes are located at the ends. There are about 250 genes in the genome of poxviruses. Replication of the poxvirus is accomplished in several stages.

How many people died from smallpox in Europe?

EPIDEMIOLOGY Smallpox reached Europe between the 5th and 7th centuries According to one estimate smallpox was claiming 400,000 European lives a year by the end of the 18th century – at a time when the population of the continent numbered less than 200 million.”