| 1 | Different hypotheses have been developed to explain the origin of Ebola outbreaks. | |
| 2 | Based on experiences with Ebola, control measures can have an immediate impact by interrupting chains of transmission. | |
| 3 | The virus is not related to certain other viruses that can cause hemorrhagic disease, such as Ebola or dengue. | |
| 4 | About 1850 cases with over 1200 deaths have been documented since the Ebola virus was discovered. | |
| 5 | WHO is familiar with such reactions, which have been seen during previous outbreaks of the closely related Ebola haemorrhagic fever. |