About smallpox

What is smallpox?

Smallpox facts

  • Smallpox is a contagious disease caused by the variola virus.
  • Smallpox was the first disease to be eliminated from the world through public-health efforts and vaccination.
  • Smallpox still poses a threat because existing laboratory strains may be used as biological weapons.
  • Smallpox causes high fever, prostration, and a characteristic rash. The rash usually includes blister-like lesions that occur everywhere on the body.
  • Approximately one-third of people with smallpox died from the disease. Survivors were scarred for life. If the eye was infected, blindness often resulted.
  • There are new experimental medications that might be effective in smallpox, but these have not been tested in human cases since the disease has been eradicated.
  • The vaccine contains a live virus called vaccinia. It is administered by dipping a pronged piece of metal into the vaccine and then pricking the skin.
  • The vaccine has uncommon side effects that may be fatal, including infection of the heart and brain with the vaccinia strain. Serious side effects are more common with the initial vaccine and are uncommon with second doses.
  • The vaccine is currently only given to selected military personnel and laboratory workers who handle the smallpox virus.

What is smallpox?

Smallpox is an infectious disease of the past that was eliminated by vaccination. The disease was caused by the variola virus, which spread from person to person. Affected people became very ill with a high fever and a characteristic rash. Up to one-third of people with smallpox died. Although the disease has been wiped out, samples of the virus still exist in high-security laboratories in the United States and Russia. This has led to concerns about use of the virus in biological warfare. For this reason, some military personnel are still vaccinated against smallpox.

What is the history of smallpox?

Smallpox is thought to have existed for more than 12,000 years. Evidence of infection can be found in mummies from ancient Egypt, including the mummy of Ramses V. Smallpox entered the New World in the 16th century, carried by European explorers and conquistadors. Because the aboriginal inhabitants had no immunity to the disease, smallpox often decimated native populations. There are even reports where infected blankets were used to intentionally infect Native American populations in the 18th century -- one of the early examples of biological warfare. During the 20th century, it is estimated that there were 300 million to 500 million deaths from smallpox worldwide, compared to 100 million from tuberculosis.

It was not until the end of the 18th century that an effective method of vaccination was developed. It was an English scientist named Edward Jenner who discovered it. Jenner observed that milkmaids often got a mild disease called cowpox and that this seemed to make them immune to smallpox. His vaccination strategy involved transferring the blister fluid from a person with cowpox to a person who had not yet had smallpox. This gave the susceptible person a cowpox infection (which was usually mild) and conveyed protection from smallpox. After a time, a virus similar to cowpox, called vaccinia, was substituted in the vaccine.

The last naturally occurring case of smallpox was in Somalia in 1977. In 1980, the World Health Organization (WHO) certified that the world was finally free of smallpox. Thus, smallpox was the first disease to be entirely eradicated. Campaigns are now under way to try to eliminate other diseases such as polio and measles.

The WHO has encouraged all member nations to destroy any remaining laboratory cultures of the virus. However, the rise of biological warfare technology led to concerns that smallpox could be weaponized and used in bioterrorism. Both the U.S. and Russia decided to retain their stockpiles in case they were needed to produce novel vaccines against a biological agent. This has understandably stirred up controversy. Supporters of retaining the cultures note that existing stocks of the virus have been used to develop and test new treatments and vaccines. The entire viral genome has been sequenced, leading to concerns that the virus may be recreated even if current stocks are destroyed.

Smallpox is a deadly disease and is on the list of potential biological weapons that are considered to pose the greatest threat to public health. Other agents on this list include anthrax, plague, smallpox, botulism, tularemia, and the viral hemorrhagic fevers, including Ebola and Marburg viruses.

What are the symptoms for smallpox?

Severe body pain symptom was found in the smallpox condition

The first symptoms of smallpox usually appear 10 to 14 days after you're infected. During the incubation period of seven to 17 days, you look and feel healthy and can't infect others.

Following the incubation period, a sudden onset of flu-like signs and symptoms occurs. These include:

  • Fever
  • Overall discomfort
  • Headache
  • Severe fatigue
  • Severe back pain
  • Vomiting, possibly

A few days later, flat, red spots appear first on your face, hands and forearms, and later on your trunk. Within a day or two, many of these Lesions turn into small Blisters filled with clear fluid, which then turns into pus. Scabs begin to form eight to nine days later and eventually fall off, leaving deep, pitted scars.

Lesions also develop in the mucous membranes of your nose and mouth and quickly turn into sores that break open.

What are the causes for smallpox?

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. The virus can be transmitted through the air by droplets that escape when an infected person coughs, sneezes or talks.
  • Indirectly from an infected person. In rare instances, airborne virus can spread farther, possibly through the ventilation system in a building, infecting people in other rooms or on other floors.
  • Via contaminated items. Smallpox can also spread through contact with contaminated clothing and bedding, although the risk of infection from these sources is less common.
  • As a terrorist weapon, potentially. A deliberate release of smallpox is a remote threat. However, because any release of the virus could spread the disease quickly, government officials have taken numerous precautions to protect against this possibility, such as stockpiling smallpox vaccine.

What are the treatments for smallpox?

No cure for smallpox exists. In the event of an infection, treatment would focus on relieving symptoms and keeping the person from becoming dehydrated. Antibiotics might be prescribed if the person also develops a bacterial infection in the lungs or on the skin.

Tecovirimat (Tpoxx), an antiviral drug, was approved for use in the U.S. in 2018. However, it wasn't tested in people who are sick with smallpox, so it's not known if it is an effective drug option. A trial tested its safety in humans and found it to be as safe as the placebo. Other antiviral drugs continue to be studied.

What are the risk factors for smallpox?

In the past, the major risk factor for getting smallpox infection was close association with another infected person with smallpox who expelled virus-contaminated droplets in coughs and sneezes; infrequently, some patients may have obtained the disease from touching heavily contaminated items and then transferring viruses to their own mucous membranes. Currently, the major risk factors are working in highly specialized laboratories that may still have smallpox viruses in storage by accident or become contaminated while either working with the viruses (for example, a pox virus lab tech, vaccinator, or transporter) or using the viruses as a biological weapon.

Is there a cure/medications for smallpox?

There is no cure for smallpox. However, vaccines are used to prevent smallpox.

  • With the help of vaccines, smallpox has been eradicated. If smallpox occurs again, the patient would be treated by relieving symptoms and preventing against being dehydration.
  • Vaccines of smallpox have been developed from a virus named Vaccinia.
  • Although Vaccinia has a similarity with poxvirus, it is not that harmful.

Drugs used as Antiviral

  • In 2018, Tecovirimat was approved as a medicine for smallpox. In the laboratory test, it was found that tecovirimat could stop the growth of the virus that causes smallpox. But it was tested in healthy people only.
  • In 2021, brincidofovir was approved and given to healthy people to prevent the virus that causes smallpox or another similar disease.
  • Cidofovir has also been effective in preventing the virus growth that causes smallpox.
  • The drugs mentioned above have not been tested in people having smallpox. Therefore, it cannot be said with confidence whether these drugs are effective in use as medications for smallpox or not. However, the use of these drugs can be considered if the outbreak of smallpox happens in the future.
  • The vaccines are effective and become successful in protecting people against the virus causing smallpox before or within one week of coming into contact with the virus.

Fever,Headache,Severe body pain,Vomiting,Red spot on the skin,Fatigue,Overall discomfort
Fever,Skin rash,Permanent scars on the body
Ketoconazole or Vaccines and other drugs including tecovirimat, brincidofovir, cidofovir

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