Smallpox

Smallpox is a viral disease marked by fever and a progressively worsening skin rash. Thanks to the development of an effective vaccine, smallpox was declared eradicated in 1980. Nevertheless, the FDA has approved specific treatments for smallpox to counter potential threats, such as a bioterrorism attack.

Causes

Here’s an in-depth look at the causes of smallpox:

• Cause of Infection: The variola virus, a highly contagious pathogen, is responsible for causing smallpox.

• Primary Mode of Transmission: The virus mainly spreads through direct, face-to-face contact with an infected individual. This often occurs when an infected person coughs, sneezes, or talks, which releases respiratory droplets containing the virus.

• Secondary Mode of Transmission: Less commonly, smallpox can spread through indirect contact. This can happen via contaminated clothing or bedding that harbors the virus.

• Current Status and Concerns: While smallpox was eradicated in 1980, there are still concerns about the use of the variola virus as a bioweapon. Continuous monitoring and preparedness efforts remain essential to address such potential threats.

Symptoms

Here are the symptoms associated with smallpox, outlining how the disease progresses:

• Smallpox starts after an incubation period of 7 to 19 days, typically averaging 10 to 14 days, with flu-like symptoms.

• Initial symptoms include high fever, severe headaches, muscle aches, back pain, and occasionally vomiting.

• A rash follows these symptoms, beginning with red spots in the mouth.

• These red spots spread across the body, including the face, arms, legs, hands, and feet.

• The spots evolve into sores, which then develop into fluid-filled blisters that fill with pus over approximately two days.

• As the disease progresses, the pustules crust over and form scabs.

• The infectious period continues until all scabs have fallen off, typically lasting up to three weeks from the appearance of the rash.

• Smallpox is highly contagious, particularly when the rash is present.

Diagnosis

Historically, smallpox diagnosis relied on observing characteristic symptoms and the appearance of the rash. Early signs included a high fever, intense headache, and body aches, soon followed by a distinctive rash. The rash began as red spots in the mouth and on the face, spreading to the rest of the body, developing into pustules that crusted over, often leaving scars. When smallpox was common, these pronounced physical symptoms guided healthcare professionals in making a diagnosis. If smallpox were to resurface today, it would pose a significant public health challenge, necessitating laboratory confirmation. Tissue samples would be analyzed in specialized laboratories, such as those at the Centers for Disease Control and Prevention, to confirm the presence of the variola virus accurately.

Treatments

Although naturally occurring smallpox was eradicated in the late 20th century, direct treatments haven't been tested due to the absence of new cases. Nonetheless, in the event of a reemergence, several antiviral medications, such as Tecovirimat and Brincidofovir, have been approved by the FDA for use against smallpox. These have demonstrated effectiveness in inhibiting the virus in lab and animal studies, though their efficacy in humans specifically against smallpox remains unproven. Cidofovir, although not FDA-approved for smallpox, might still be considered after a thorough risk evaluation. These medications, particularly Tecovirimat and Brincidofovir, are stockpiled as part of preparedness efforts for any potential outbreaks.

Medications

Here is critical information concerning smallpox-related medications:

• The worldwide eradication of smallpox was achieved through successful vaccination initiatives. However, antiviral drugs have been developed as safeguards against possible future outbreaks.

• Tecovirimat (TPOXX) and Brincidofovir (TEMBEXA) are two FDA-approved antiviral drugs intended for use against smallpox.

• While these drugs haven't been directly tested on individuals with smallpox, they have displayed potential in laboratory experiments involving similar diseases. Their safety has been confirmed through trials involving healthy participants.

• Another antiviral, Cidofovir, is considered an off-label option for treating smallpox, despite not having FDA approval for this specific use.

• To ensure public health safety, these medications are stored and ready for deployment in case of a smallpox emergency.

Prevention

Key points regarding smallpox prevention include:

• Smallpox was eradicated worldwide in 1980, following successful vaccination campaigns by the World Health Organization.

• Routine vaccination against smallpox has been discontinued since the disease no longer occurs naturally.

• In the case of an outbreak, possibly due to bioterrorism, reserves of smallpox vaccines are available for emergency use.

• Vaccination may still be given to high-risk groups, such as specific laboratory staff and military personnel who might be exposed to the virus.

• The smallpox vaccine is based on the vaccinia virus, which is similar to the smallpox virus and was critical in preventing the disease's spread.