Smallpox is an infectious disease that was highly contagious and often left infected people with disfiguring scars. Symptoms included fever, vomiting, mouth sores, and a terrible skin rash. No cure exists for smallpox, although there is a vaccine to prevent it. Fortunately, though, it was declared globally eradicated in 1980. The last naturally occurring case of smallpox occurred in 1977. Some samples of the virus, however, have been saved so that researchers can understand more about what caused this illness and how to prevent it in the future.


1. Smallpox Causes

A viral infection caused smallpox -- specifically, the variola virus. Experts believe two variants, variola major and variola minor, are to blame for the spread of the disease. The first appearance of smallpox in history is unknown, but researchers and historians posit that this virus evolved from another virus affecting African rodents between 68,000 and 16,000 years ago. Research suggests Variola major originated in Asia, while variola minor came from West Africa at a later time. Both spread across the globe at an alarming rate when the illness was active.

what causes smallpox

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