Smallpox - Vejthani Hospital | JCI Accredited International Hospital in Bangkok, Thailand.

Smallpox

Overview

Smallpox is a severe and potentially fatal viral disease that has historically impacted humans. It spreads easily from one person to another and can leave survivors with permanent scars or disfigurement. Despite its severity, smallpox was declared eradicated globally in 1980, thanks to the effectiveness of vaccination campaigns. The last natural case was recorded in 1977, and since then, the virus no longer exists naturally in the environment.

However, samples of the smallpox virus have been preserved for research, raising concerns about its potential creation in laboratories and use as a bioweapon. Scientific progress has indeed made it feasible to synthesize smallpox in a lab, which poses a risk of its use in biological warfare.

Today, routine vaccination against smallpocket is not recommended for the general public due to the absence of natural cases. Nevertheless, the existence of vaccines and the development of new antiviral drugs ensure that there are preventive and therapeutic measures available should the virus ever re-emerge.

Symptoms

The symptoms of smallpox generally appear 12 to 14 days after exposure to the virus, although the virus can be present in the body for 7 to 19 days before symptoms manifest. This phase is known as the incubation period.

  • Initial symptoms: Following the incubation period, sudden onset of flu-like symptoms occurs:
    • Fever
    • Muscle aches
    • Headache
    • Severe fatigue
    • Severe back pain
    • Occasional vomiting
  • Progression of symptoms: A few days after the initial symptoms, flat, red spots develop. These lesions usually begin in the mouth and on the tongue before spreading to the skin, affecting the face, arms, and legs first, then the torso, hands, and feet.
  • Advanced stages: Within a day or two of their appearance, the red spots evolve into small blisters filled with clear fluid, which later become pus-filled pustules. By 8 to 9 days after their formation, scabs begin to form over these pustules. The scabs eventually fall off, often leaving deep, pitted scars.
  • Transmission: Smallpox is contagious from the time the rash appears until the scabs fall off, allowing the disease to be spread from person to person during this period.

Causes

Smallpox, caused by the variola virus, manifests in two forms: variola major and variola minor, also known as variola alastrim. Variola major was responsible for the majority of smallpox cases and fatalities, with mortality rates exceeding 30%. In contrast, variola minor, while producing similar but milder symptoms, resulted in death in only about 1% of cases.

The disease could be transmitted by:

  • Direct contact (person to person): The smallpox virus can spread through contact with an infected person. When an infected individual coughs, sneezes, or speaks, the virus might be shared. Smallpox can also occur as a result of skin sore contact.
  • Indirect contact: In rare cases, smallpox can travel through the air within structures and infect others in surrounding spaces or floors.
  • Through contamination: Contact with contaminated bedding and clothing can potentially spread smallpox. However, this is a less common style of contracting smallpox.
  • Biological weapon (unlikely): It is unlikely that smallpox will be used as a weapon. However, countries are bracing for the prospect that releasing the virus might quickly spread the disease.