This article discusses the diagnosis and medical management of smallpox.
The poxviruses are a family of large, enveloped deoxyribonucleic acid (DNA) viruses. The most notorious poxvirus is variola, the causative agent of smallpox. Smallpox was an important cause of morbidity and mortality in the developing world until 1980 when it was declared eradicated. The concept of using variola virus in warfare is an old one. The actual potential of variola virus as a biological weapon remains controversial. The discontinuation of routine vaccination has rendered civilian and military populations more susceptible to a disease that is infectious by aerosol and relatively easy to produce on a large-scale basis. The World Health Organization (WHO) continues to debate whether all stocks of variola virus should be destroyed. Clinical manifestations of smallpox begin acutely with malaise, fever, rigors, vomiting, headache, and backache; 15 percent of patients develop delirium. Approximately 10 percent of light-skinned patients exhibit a rash during this phase. Later, a discrete rash about the face, hands, and forearms appears. Following subsequent eruptions on the lower extremities, the rash spreads centrally during the next week to the trunk. Rapid diagnostic tests may play an important role in discriminating smallpox from other diseases. Earlier stages of the rash could be mistaken for varicella. Quarantine with respiratory isolation should be applied to secondary contacts for 17 days after the exposure. Vaccinia vaccine remains the preeminent countermeasure for pre-exposure prophylaxis against smallpox. Vaccina vaccination, vaccinia immune globulin, and methisazone each possess some efficacy in postexposure prophylaxis. 137 references