Table of ContentsView AllTable of ContentsTypesSymptomsCausesDiagnosisTreatmentPrognosis
Table of ContentsView All
View All
Table of Contents
Types
Symptoms
Causes
Diagnosis
Treatment
Prognosis
Though you’re not likely to encounter smallpox in the wild, it still exists in two labs. These two labs are the Centers for Disease Control and Prevention (CDC) in the United States and the Vector Institute in Russia. These samples are kept to test drugs and conduct other experiments.
The virus is deadly and highly contagious.
This article will discuss the different types of smallpox and its related viruses. It will cover the symptoms, causes, diagnosis, and treatment for smallpox historically and what how they might change if the virus were to cause a new outbreak. We’ll also discuss the outlook for smallpox infection.
Joe Raedle / Staff / Getty Images
Types of Smallpox
The type of smallpox virus that causes a deadly human disease is the variola virus. It occurs as two closely related virus strains:
Variola major has four forms:
The flat and hemorrhagic types are more deadly than others but less common.
The first smallpox vaccine used the cowpox virus in the same way that variolation had used scabs from people with smallpox. By inoculating a person with the milder cowpox virus, they developed immunity that kept them safe from smallpox.
Modern vaccines are made with the vaccinia virus, which replaced cowpox sometime in the 1800s.
Other viruses in the same family as smallpox exist and infect animals and humans. These Orthopoxviruses often look like smallpox and cause similar symptoms. They can cause severe disease.These include:
Smallpox Symptoms
Smallpox infection takes seven to 19 days to take hold and show symptoms. At this point, the person who has contracted the virus isn’t contagious.
It feels like the flu for the first two to four days.Symptoms of smallpoxmay include:
A few days after becoming symptomatic, a person with smallpox develops a rash. The sores feel like firm round nubs in the skin that form red bumps. They first show up inside the mouth, throat, and tongue.
When the sores in the mouth break down, the rash appears on the skin of the face and around the eyes, spreading them to the forearm, then to the belly and legs. Sometimes, these sores appear on the palms of the hands and feet. This process takes about a day. The fever starts to break, and the person begins to feel better.
The sores become bubbles of clear fluid, eventually filling withpus. The fever may come back at this point. The sores eventually crust over, usually three weeks after they show up. When all the scabs fall off, the person can no longer transmit the virus.
Complications of smallpox infections include:
A virus causes smallpox. This virus lives only in humans and doesn’t exist in the wild anymore, so there are no more cases of smallpox. The virus only exists as samples in labs.
If these droplets are tiny enough, they may spread the virus through the air in enclosed settings.
Healthcare professionals diagnose smallpox with a physical exam and medical history. They’ll ask about your symptoms and may perform blood tests to look for the virus that causes it.
There is no specific treatment for smallpox because no treatment has been tested in humans with smallpox since it was eradicated.
Antiviral drugsthat may treat smallpox in an emergency include:
Two vaccines have been created and stockpiled in the case of a smallpox outbreak. These vaccines can stop people from getting sick and make the disease less severe if given within a week of contact with the virus.
Medical care was very different before smallpox was eradicated.Treatment for smallpoxoften only involved supportive care.
You can survive smallpox. When the virus was circulating, about 30% of those with variola major died. Only about 1% of those with variola minor died.Severe forms of the disease are more deadly and would have a lower survival rate.
If an outbreak of smallpox were to happen today, modern medicine and antiviral drugs would likely improve these numbers. People are no longer routinely vaccinated for smallpox, but the U.S. stockpile of smallpox vaccine is sufficient to vaccinate everyone in the United States in case of an outbreak.
Summary
Smallpox can appear in different ways, but typically a person gets a high fever and feels a flu-like illness. They develop sores in their mouth first, then their face, limbs, and abdomen.
The virus is transmitted through contact with fluid from the sores. A person may breathe out droplets of saliva containing the virus from sores in the mouth. It can also transfer to surfaces from sores on the body. Historically, smallpox killed about one-third of the people who contracted the virus that causes it.
Three current antiviral drugs may help treat people who contract smallpox during an outbreak. There is also a stockpile of smallpox vaccines. Vaccination may protect people if given soon after exposure to the virus.
13 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.History of smallpox.U.S. Food and Drug Administration.Smallpox.Centers for Disease Control and Prevention.Clinical disease.Centers for Disease Control and Prevention.Poxvirus diseases.Centers for Disease Control and Prevention.Smallpox & other Orthopoxvirus-associated infections.World Health Organization.Mpox (monkeypox) outbreak 2022 - GlobalPrabhu M, Yogisharadhya R, Pavulraj S, et al.Camelpox and buffalopox: two emerging and re-emerging Orthopox viral diseases of India.Adv Anim Vet Sci. 2015;3:527–41. doi:10.14737/journal.aavs/2015/3.10.527.541Roy P, Chandramohan A.Buffalopox disease in livestock and milkers, India.Emerging Infectious Diseases. 2021;27(7):1989-1991. doi:10.3201/eid2707.202111Centers for Disease Control and Prevention.Signs and symptoms.Centers for Disease Control and Prevention.What is smallpox?Centers for Disease Control and prevention.Transmission.Centers for Disease Control and Prevention.Diagnosis & evaluation.Centers for Disease Control.Prevention and treatment.
13 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.History of smallpox.U.S. Food and Drug Administration.Smallpox.Centers for Disease Control and Prevention.Clinical disease.Centers for Disease Control and Prevention.Poxvirus diseases.Centers for Disease Control and Prevention.Smallpox & other Orthopoxvirus-associated infections.World Health Organization.Mpox (monkeypox) outbreak 2022 - GlobalPrabhu M, Yogisharadhya R, Pavulraj S, et al.Camelpox and buffalopox: two emerging and re-emerging Orthopox viral diseases of India.Adv Anim Vet Sci. 2015;3:527–41. doi:10.14737/journal.aavs/2015/3.10.527.541Roy P, Chandramohan A.Buffalopox disease in livestock and milkers, India.Emerging Infectious Diseases. 2021;27(7):1989-1991. doi:10.3201/eid2707.202111Centers for Disease Control and Prevention.Signs and symptoms.Centers for Disease Control and Prevention.What is smallpox?Centers for Disease Control and prevention.Transmission.Centers for Disease Control and Prevention.Diagnosis & evaluation.Centers for Disease Control.Prevention and treatment.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Centers for Disease Control and Prevention.History of smallpox.U.S. Food and Drug Administration.Smallpox.Centers for Disease Control and Prevention.Clinical disease.Centers for Disease Control and Prevention.Poxvirus diseases.Centers for Disease Control and Prevention.Smallpox & other Orthopoxvirus-associated infections.World Health Organization.Mpox (monkeypox) outbreak 2022 - GlobalPrabhu M, Yogisharadhya R, Pavulraj S, et al.Camelpox and buffalopox: two emerging and re-emerging Orthopox viral diseases of India.Adv Anim Vet Sci. 2015;3:527–41. doi:10.14737/journal.aavs/2015/3.10.527.541Roy P, Chandramohan A.Buffalopox disease in livestock and milkers, India.Emerging Infectious Diseases. 2021;27(7):1989-1991. doi:10.3201/eid2707.202111Centers for Disease Control and Prevention.Signs and symptoms.Centers for Disease Control and Prevention.What is smallpox?Centers for Disease Control and prevention.Transmission.Centers for Disease Control and Prevention.Diagnosis & evaluation.Centers for Disease Control.Prevention and treatment.
Centers for Disease Control and Prevention.History of smallpox.
U.S. Food and Drug Administration.Smallpox.
Centers for Disease Control and Prevention.Clinical disease.
Centers for Disease Control and Prevention.Poxvirus diseases.
Centers for Disease Control and Prevention.Smallpox & other Orthopoxvirus-associated infections.
World Health Organization.Mpox (monkeypox) outbreak 2022 - Global
Prabhu M, Yogisharadhya R, Pavulraj S, et al.Camelpox and buffalopox: two emerging and re-emerging Orthopox viral diseases of India.Adv Anim Vet Sci. 2015;3:527–41. doi:10.14737/journal.aavs/2015/3.10.527.541
Roy P, Chandramohan A.Buffalopox disease in livestock and milkers, India.Emerging Infectious Diseases. 2021;27(7):1989-1991. doi:10.3201/eid2707.202111
Centers for Disease Control and Prevention.Signs and symptoms.
Centers for Disease Control and Prevention.What is smallpox?
Centers for Disease Control and prevention.Transmission.
Centers for Disease Control and Prevention.Diagnosis & evaluation.
Centers for Disease Control.Prevention and treatment.
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