Smallpox: Symptoms, Causes, Treatment

What are the symptoms of smallpox?

Smallpox is a serious and contagious disease caused by the variola virus. The symptoms of smallpox typically follow a predictable course, with different stages of the disease. Here’s an overview of the symptoms:

1. Incubation Period (7-17 Days):

No Symptoms: During this period, the virus is in the body, but the infected person does not yet feel sick or show any symptoms.

2. Initial Symptoms (Prodrome Phase) (2-4 Days):

High Fever: Often above 101°F (38.3°C).
Severe Headache: Intense and persistent.
Backache: Pain in the lower back, sometimes severe.
Fatigue and Weakness: A general feeling of being unwell.
Vomiting: May occur in some cases.
Abdominal Pain: Some people experience discomfort or pain in the abdomen.

3. Early Rash (2-4 Days):

Small Red Spots: The rash typically begins as small red spots on the tongue and in the mouth.
Sores: These spots develop into sores that break open and spread the virus into the mouth and throat.
Spread to Skin: The rash then spreads to the face, arms, legs, hands, and feet, eventually covering the entire body within 24 hours.

4. Pustular Rash and Scabs (5-10 Days):

Raised Bumps: The rash evolves into raised bumps filled with a thick, opaque fluid.
Pustules: These bumps become firm, round, and deeply embedded in the skin.
Crusting Over: The pustules eventually begin to crust over and form scabs.
Scabs Fall Off: The scabs fall off, leaving pitted scars (pockmarks).

5. Resolution:

Scarring: Once the scabs have fallen off, the affected skin may be left with permanent scars, often most noticeable on the face.
Contagiousness: The infected person is contagious until the last scab falls off.

Smallpox was eradicated worldwide by 1980 due to an aggressive global vaccination campaign. However, before its eradication, smallpox was a deadly disease, with a significant fatality rate. Today, smallpox no longer occurs naturally, but concerns about its use as a bioterrorism agent have led to ongoing research and preparedness efforts.

What are the causes of smallpox?

Smallpox is caused by the variola virus, a member of the orthopoxvirus genus. This virus is the sole cause of smallpox and is highly contagious.

Transmission of the Variola Virus:

Person-to-Person Contact:

Smallpox spreads primarily through direct, close contact with an infected person. This can occur via respiratory droplets released when the infected person coughs, sneezes, or talks.
The virus can also spread through direct contact with the sores or scabs of an infected person.

Airborne Transmission:

In some cases, smallpox can spread through the air in enclosed spaces, such as within a building, especially if the ventilation is poor. However, this mode of transmission is less common.

Contaminated Objects (Fomites):

The virus can also spread through contact with contaminated objects, such as bedding, clothing, or other items that have been in contact with an infected person. The variola virus can survive on these materials for some time.

Biological Warfare:

Although naturally occurring smallpox has been eradicated, there is concern that the variola virus could be used as a biological weapon, leading to a resurgence of the disease.

Note on Variola Virus:

The variola virus has two major forms:

Variola Major: The more severe form of the disease, associated with a higher mortality rate.
Variola Minor: A milder form of the disease, with a lower mortality rate.

The eradication of smallpox was achieved through a global vaccination campaign, and no natural cases have occurred since 1977. The only known stocks of the variola virus are held under strict security in laboratories in the United States and Russia.

What is the treatment for smallpox?

There is no specific cure for smallpox once someone is infected, but treatment focuses on managing symptoms and preventing complications. The following approaches have been used historically and could be applied in case of an outbreak:

1. Supportive Care:

Hydration: Ensuring the patient remains hydrated, especially if fever or vomiting is present.
Pain Management: Using pain relievers to alleviate symptoms such as headaches, back pain, and muscle aches.
Fever Reduction: Medications may be given to reduce fever and keep the patient comfortable.
Antibiotics for Secondary Infections: Since smallpox sores can become infected with bacteria, antibiotics may be used to treat these secondary bacterial infections.

2. Antiviral Medications:

Tecovirimat (TPOXX): An antiviral drug approved to treat smallpox in the event of an outbreak. It inhibits the virus’s ability to spread within the body.
Cidofovir and Brincidofovir: These are other antiviral drugs that may be effective against the variola virus, though they are primarily used to treat other viral infections.

3. Isolation:

Strict Isolation: Infected individuals must be isolated to prevent the spread of the virus. This would typically involve hospitalizing the patient in a specialized isolation unit.
Contact Tracing: Identifying and monitoring people who may have come into contact with the infected person to prevent further spread.

4. Vaccination:

Post-Exposure Prophylaxis: Vaccination can be effective if given within 3-4 days after exposure to the virus, possibly preventing the disease or lessening its severity.
Ring Vaccination: In case of an outbreak, a strategy known as ring vaccination may be employed, where close contacts of an infected person are vaccinated to contain the spread.

5. Managing Complications:

Respiratory Support: If the patient develops complications such as pneumonia, respiratory support may be necessary.
Wound Care: Proper care of skin lesions to prevent secondary infections and promote healing.

Preventive Measures:

Vaccination: Smallpox vaccination is highly effective in preventing the disease. However, routine vaccination was stopped after the disease was eradicated. In the event of an outbreak, vaccination would be the primary preventive measure.
Public Health Measures: Quick identification of cases, quarantine, and vaccination of the population would be crucial in preventing a large-scale outbreak.

Historical Context:

Smallpox vaccination was a key factor in the eradication of the disease. The vaccine uses a related virus, vaccinia, to stimulate immunity against smallpox. The global vaccination campaign led to the eradication of smallpox in 1980.

While smallpox is no longer a naturally occurring disease, these treatment strategies would be crucial in the event of an outbreak, whether due to accidental release or as a result of bioterrorism.