What is the Variola Virus?

Variola virus is a self-replicating pathogen that induces the onset of smallpox. Exclusively a human-oriented disease, variola virus has been considered to be eradicated for three decades, but portions of the pathogen still exist for research purposes only. In the absence of a cure, vaccination is the only method of variola virus prevention. Due to the threat of its use in biological warfare, variola virus is being revisited to gain a better understanding of its nature, transmission, and potential treatment options.

Commonly known as smallpox, this member of the Poxviridae family of viruses is extremely invasive. Once an individual is exposed through the inhalation of infected, airborne droplets, the virus uses the individual's cells as a means of transportation to the lymphatic system before settling in the bloodstream. Depending on the severity of infection, one may develop a common presentation of ordinary smallpox or a more pronounced, dermal-based hemorrhagic form of the virus. Individuals who have received a smallpox vaccination may still develop infection if exposed to variola virus, a presentation known as modified smallpox. Major forms of the smallpox virus, including flat and hemorrhagic presentations, carry a significantly high mortality rate.

Due to widespread vaccination and the confirmed eradication of smallpox in 1980, a confirmed case of variola virus today could cause the issuance of a worldwide health emergency and ignite fears of a pandemic. If someone were to become infected with the variola virus and exhibit signs of a smallpox rash, a tissue sample would be taken and submitted to the Centers for Disease Control and Prevention (CDC). The symptomatic individual would be immediately hospitalized and placed in isolation pending a confirmation of a diagnosis by the CDC.

Considering smallpox symptoms can mimic those of other conditions, including monkey- and chickenpox, a complete medical history of the individual must be taken and a complete physical examination performed. Health care providers are trained to recognize the characteristic smallpox rash and other signs and symptoms of the disease. To confirm a diagnosis, in addition to a tissue sample, lab tests may be performed, including a viral culture, where fluid samples are obtained for analysis.

The incubation period for smallpox is generally a little over two weeks. Individuals will usually develop flu-like signs, including fever, persistent headache, and pronounced fatigue. Following the development of initial symptoms, individuals will develop the tell-tale smallpox rash that initially presents as flat lesions before forming blisters and pustules. The smallpox rash will usually form on the face and upper torso before descending to the trunk and lower extremities. The rupturing of smallpox blisters and pustules can induce extreme pain, and the overall progression of lesion development can be fatal for some people.

Treatment for variola virus is generally centered on symptom management and the eradication of any underlying bacterial infection. Those who exhibit signs of secondary infection may undergo the aggressive administration of antibiotic medications. In some cases, prescription analgesic medications may be given to alleviate discomfort. Supportive therapy, including supplemental oxygen, may be administered to those with impaired respiration. Extensive scarring generally exists in the wake of healed lesions that have shed their scabs.