What does variola major cause?

Smallpox is caused by infection with the variola virus. The virus can be transmitted: Directly from person to person. Direct transmission of the virus requires fairly prolonged face-to-face contact.

What are 4 symptoms of smallpox?

Smallpox is an infectious disease caused by the variola virus. It is characterized by fever, a general feeling of ill health (malaise), headaches and back pain. These initial symptoms are followed by a rash and small, raised bumps or lesions (pocks) within two or three days.

How does variola affect the body?

Smallpox can cause a severe rash over the whole body that can leave scars. Other symptoms include high fever and severe headache or body aches. Death occurs in about 30 percent of infected people. Some survivors may suffer blindness.

What disease is caused by variola?

Before smallpox was eradicated, it was a serious infectious disease caused by the variola virus. It was contagious—meaning, it spread from one person to another. People who had smallpox had a fever and a distinctive, progressive skin rash.

What is the difference between variola major and 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 type of virus is variola?

The variola virus is a large, brick-shaped, double-stranded DNA virus that serologically cross-reacts with other members of the poxvirus family, including ectromelia, cowpox, monkeypox, vaccinia, and camelpox. Unlike other DNA viruses, the variola virus multiplies in the cytoplasm of parasitized host cells.

How is smallpox diagnosed?

Smallpox can be diagnosed based on the patient’s clinical signs and symptoms. The disease can be definitively diagnosed by isolation of the virus from the blood or lesions, or by identification of antibodies in the blood made in response to the virus.

What body systems are affected by smallpox?

The virus starts in the lungs. From there, the virus invades the bloodstream and spreads to the skin, intestines, lungs, kidneys, and brain. The virus activity in the skin cells creates a rash that starts as macules (flat, red lesions).

What are some complications of smallpox?

Most patients who survive smallpox have extensive scarring of the skin….Other complications may include:

  • Eye problems including corneal ulceration and blindness.
  • Bronchopneumonia.
  • Arthritis.
  • Osteomyelitis.

What does the variola virus look like?

Characteristics of variola virus The variola virus is a large, brick-shaped, double-stranded DNA virus that serologically cross-reacts with other members of the poxvirus family, including ectromelia, cowpox, monkeypox, vaccinia, and camelpox.

Where is the variola virus found?

Currently, there is no evidence of naturally occurring smallpox transmission anywhere in the world. Although a worldwide immunization program eradicated smallpox disease decades ago, small quantities of smallpox virus officially still exist in two research laboratories in Atlanta, Georgia, and in Russia.