Which viral hemorrhagic fever is known to have the highest fatality rate?

Ebola virus disease is recognized for having one of the highest fatality rates among viral hemorrhagic fevers. The various strains of the Ebola virus, particularly the Zaire strain, have recorded fatality rates that can exceed 90% in certain outbreaks. This high mortality is attributed to the virus's capacity to cause severe symptoms, including hemorrhaging, multi-organ failure, and a rapid decline in host immune response, which ultimately leads to a poor prognosis for patients infected with it.

In contrast, while Marburg virus disease also presents a significant risk of mortality, its fatality rate generally does not surpass that of the most virulent strains of Ebola. Lassa fever and Hantavirus pulmonary syndrome, while serious, tend to have lower fatality rates compared to Ebola virus disease. Lassa fever's mortality rate can be around 1% to 15%, and Hantavirus pulmonary syndrome varies but typically remains below 50% in reported cases.

Understanding the lethality associated with each of these viral hemorrhagic fevers is critical for public health responses, especially in outbreak situations, where timely intervention can mitigate the spread and impact of such infections.