What is the difference between variola major and variola minor?

What is the difference between variola major and variola minor?

Smallpox is caused by 1 of 2 closely related strains: variola major and variola minor. The 2 viruses are indistinguishable except by polymerase chain reaction (PCR) testing. Variola minor infection (known as Alastrim) causes fewer systemic symptoms, a less extensive rash, less scarring, and fewer fatalities.

What is variola major?

Variola major is the severe form of smallpox, with a more extensive rash and higher fever. It is also the most common form of smallpox. There are four types of variola major smallpox: ordinary (the most frequent); modified (mild and occurring in previously vaccinated persons); flat; and hemorrhagic.

What is the structure of the variola virus?

Variola virus has a double stranded DNA genome, meaning it has two strands of DNA twisted together, like our cells have. The DNA is bound to proteins in a nucleoprotein complex called the core, shaped like a dumbbell in the center of the virus.

What is small pox look like?

The rash looks like red bumps that gradually fill with a milky fluid. The fluid-filled bumps are all in the same stage at the same time, compared to chickenpox, where the skin blisters are in different stages of appearance with a mix of blisters, bumps, and crusted lesions at a given time.

Does variola virus have a capsid?

Orthopoxviruses have an outside envelope and a second membrane underneath. Instead of a capsid, poxviruses have a nucleosome which contains DNA, and is surrounded by its own membrane(5). They contain single, linear, double-stranded DNA molecules of 130 to 375 kb pairs and replicate in the cell cytoplasm(4).

What are small POXS?

Overview. Smallpox is a contagious, disfiguring and often deadly disease that has affected humans for thousands of years. Naturally occurring smallpox was wiped out worldwide by 1980 — the result of an unprecedented global immunization campaign. Samples of smallpox virus have been kept for research purposes.

Does variola have an envelope?

The virion is a brick-shaped structure with a diameter of about 200 nm. Its lipoprotein outer membrane (envelope) encloses a single linear, double-stranded DNA.

What is the size of the variola virus?

Virion morphology: Brick-shaped virion approximately 200 nm in diameter, 250 to 300 nm long, and 250 nm high (International Committee on Taxonomy of Viruses); about the size of a bacterial spore. Enveloped. Dumbbell-shaped core containing nucleic acid and surrounded by a series of membranes.

What is Variola minor (alastrim)?

Variola minor infection (known as Alastrim) causes fewer systemic symptoms, a less extensive rash, less scarring, and fewer fatalities. During the era of naturally occurring smallpox, several variations of variola major disease were recognized. See Table 1.

What is the history of variola virus (Varv)?

The agent of variola virus (VARV) belongs to the genus Orthopoxvirus. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) certified the global eradication of the disease in 1980.

Is Variola a biological weapon?

In the 1980s, the Soviet Union developed variola as an aerosol biological weapon and produced tons of virus-laden material annually intended for intercontinental ballistic missiles. Several factors contribute to the concern about the use of smallpox as a biological weapon:

What is the current state of research on Variola virus (V) infection?

All legitimate research with variola virus is now conducted within these two centers under biosafety level (BSL)-4 conditions, using a WHO-approved research agenda (Rotz 2010).