Smallpox : Type, Symptom, Transmission, Diagnosis, And Treatment

Smallpox is an infectious disease caused by variola major virus and variola minor virus.Variola is a large brick-shaped virus measuring approximately 302 to 350 nanometers by 244 to 270 nm, with a single linear double stranded DNA genome 186 kilobase pairs (kbp) in size and containing a hairpin loop at each end.Four orthopoxviruses cause infection in human, including variola, vaccinia, cowpox, and monkeypox.Variola minor causes a milder form of disease.Variola major causes a more serious disease.The disease is known as pox or red plague in English.Contagion from smallpox begins in small blood vessels of the skin, in the mouth and throat before disemminating.The symptoms of smallpox firstly appear twelve to fourteen days after infecting.During seven to seventeen days in incubation period, smallpox cannot infect others.Someone looks and feels healthy at that time.A few days later a rash appears on the face and spreads to hands, forearms, and later on the trunk.Within a day or two days of appearance the rash develops into abscesses that are filled fluid and pus.The abscesses break open and scab over.The scabs begin to form eight to nine days later and eventually fall off, leaving deep, pitted scars.Someone still remain contagious until the scabs fall off.

The symptoms of Smallpox

• High fever
• Headache
• Chills
• Vomiting
• Nausea
• Malaise
• Influenza
• Abdominal pain
• Muscle pain
• Severe back pain
• Severe fatigue
• Prostration

Types of Smallpox caused by Variola major virus :

• Ordinary Smallpox generally produces a discrete rash, in which the pustules stand out on the skin separately.
• Modified Smallpox occurs mostly in previously vaccinated people.The skin lesions tend to be fewer and evolve more quickly.
• Malignant Smallpox remains soft and flat throughout the entire illness.The lesions of malignant smallpox does not develop into pustules or pus filled bumps on the skin.
• Hemorrhagic Smallpox causes organs to leak blood into the mucous membranes and skin.

Transmission of Smallpox

• Inhalation of airbone variola virus, usually droplets expressed from the oral, nasal, or pharxngealmucosa of an infected person.
• Prolonged face-to-face contact with an infected within a distance of 1.8 meters.
• Direct contact with infected bodily fluid or contaminated objects, such as clothing, blanket, bedding.
• The virus can be transmitted throughout the course of illness, but is most frequent during the first week of the rash, when most of the skin lesions are intact.

Diagnosis of Smallpox

Some laboratory tests are done to diagnose smallpox

• An Electron Microscopy is a microscope that uses a beam accelerated electrons as a source of illumination.The electron microscopy is used to investigate the ultrastructure of a wide range of biological and inorganic specimens, including microorganisms, cells, and biopsy samples.
• Restriction  Fragment Length Polymorphism (RFLP) is a technique that exploits variation in homologous DNA sequences.
• Polymerase Chain Reaction (PCR) is a technique in molecular genetics that permits the analysis of any short sequence of DNA or RNA even in samples containing only minute quantities of DNA or RNA.It is used to reproduce selected sections of DNA or RNA for analysis.
• Enzyme Linked Immunosorbent Assay (ELISA) is a test to measure a wide variety of tests of body fluids.
• Serologic Tests are blood test that look for antibodies in the blood.

Treatment of Smallpox

• Smallpox vaccination within three days of exposure will prevent or significantly lessen the severity of smallpox symptoms in the vast majority people.Vaccination four to seven days after exposure can protect from disease or modify the severity of disease.
• No drugs are currently approved to treat smallpox.
• Cidofovir is the antiviral drug that is useful as a therapeutic agent.