Which of the following is an example of a Category A substance?

A Category A substance refers to materials that pose a significant risk to public health and require the highest level of control. These substances have a high potential for transmission and lead to severe health consequences in infected individuals.

Ebola virus is classified as a Category A substance because it is highly infectious and has a high mortality rate. It is transmitted through direct contact with bodily fluids of infected individuals, making it a serious threat in public health emergencies. Containment and strict safety protocols are essential when handling or transporting such materials, emphasizing their dangerous nature.

In contrast, Hepatitis B, HIV, and West Nile Virus (WNV) are serious health concerns but do not fall into the same risk category as Ebola. While they can cause significant illness, their modes of transmission, prevalence, and the way they are typically managed in terms of risk assessment vary. Hence, Ebola stands out as a prime example of a Category A substance.