Variola haemorrhagica is a rare and severe form of smallpox, a highly contagious viral disease caused by the variola virus. Smallpox is endemic in humans and is characterized by fever, headache, and a characteristic skin rash that ultimately develops into pus-filled blisters. Variola haemorrhagica is distinct due to the increased severity of its symptoms.
The term "variola" refers to the genus name of the variola virus, which belongs to the family Poxviridae. "Haemorrhagica" is derived from the word "haemorrhage," which refers to the abnormal bleeding that occurs in this form of smallpox. The onset of variola haemorrhagica is often sudden, with patients experiencing high fever, severe headache, and muscle pain. As the disease progresses, bleeding occurs within the skin and mucous membranes, leading to extensive hemorrhages. Bleeding can also occur internally, affecting major organs such as the liver and spleen.
Variola haemorrhagica carries a significantly higher fatality rate than other forms of smallpox. Mortality rates can exceed 90%, and death typically occurs within days of symptom onset. The disease is primarily transmitted through respiratory droplets, direct contact with infected skin lesions, or contaminated objects.
Due to the aggressive nature of variola haemorrhagica, it poses a significant public health threat. However, thanks to successful global vaccination campaigns, smallpox was eradicated in the general population in 1980. Consequently, variola haemorrhagica is now only a concern in laboratories where the virus is stored for research purposes.
