corneal scar in his left eye, 1972 The mortality rate from variola minor is approximately 1%, while the mortality rate from variola major is approximately 30%. Ordinary type-confluent is fatal about 50–75% of the time, ordinary-type semi-confluent about 25–50% of the time, in cases where the rash is discrete the case-fatality rate is less than 10%. The overall fatality rate for children younger than 1 year of age is 40–50%. Hemorrhagic and flat types have the highest fatality rates. The fatality rate for flat or late hemorrhagic type<unk>  is 90% or greater and nearly 100% is observed in cases of early hemorrhagic<unk> . The case-fatality rate for variola minor is 1% or less. There is no evidence of chronic or recurrent infection with Variola virus. In cases of flat<unk>  in vaccinated people, the condition was extremely rare but less lethal, with one case series showing a 66.7% death rate. In fatal cases of ordinary<unk> , death usually occurs between days 10-16 of the illness. The cause of death from<unk>  is not clear, but the infection is now known to involve multiple organs. Circulating immune complexes, overwhelming viremia, or an uncontrolled immune response may be contributing factors. In early hemorrhagic<unk> , death occurs suddenly about six days after the fever develops. The cause of death in early hemorrhagic cases is commonly due to heart failure and pulmonary edema. In late hemorrhagic cases, high and sustained viremia, severe platelet loss and poor immune response were often cited as causes of death. In flat<unk>  modes of death are similar to those in burns, with loss of fluid, protein and electrolytes, and fulminating sepsis. Complications Complications of<unk>  arise most commonly in the respiratory system and range from simple bronchitis to fatal pneumonia. Respiratory complications tend to develop on about the eighth day of the illness and can be either viral or bacterial in origin. Secondary bacterial infection of the skin is a relatively uncommon complication of<unk> . When this occurs, the fever usually remains elevated. Other complications include encephalitis (1 in 500 patients), which is more common in adults and may cause temporary disability; permanent pitted scars, most notably on the face; and complications involving the eyes (2% of all cases). Pustules can form on the eyelid, conjunctiva, and cornea, leading to complications such as conjunctivitis, keratitis, corneal ulcer, iritis, iridocyclitis, and atrophy of the optic nerve. Blindness results in approximately 35-40% of eyes affected with keratitis and corneal ulcer. Hemorrhagic<unk>  can cause subconjunctival and retinal hemorrhages. In 2-5% of young children with<unk> , virions reach the joints and bone, causing osteomyelitis variolosa. Bony lesions are symmetrical, most common in the elbows, legs, and characteristically cause separation of the epiphysis and marked periosteal reactions. Swollen joints limit movement, and arthritis may lead to limb deformities, ankylosis, malformed bones, flail joints, and stubby fingers. Between 65 and 80% of survivors are marked with deep pitted scars (pockmarks), most prominent on the face.
Smallpox
Monkeypox
Cowpox
Impetigo
Chickenpox
Sealpox
Molluscum contagiosum
Mumps