New model could help improve prediction of outbreaks of Ebola and Lassa fever
Many of the major new outbreaks of disease, particularly in Africa, are so-called zoonotic infections, diseases that are transmitted to humans from animals. The Ebola virus, for example, which recently killed over 11,000 people across Africa, was most likely transmitted to humans from fruit bats. Modelling how outbreaks arise and whether they will take hold or quickly die out has proved challenging, with two factors in particular being difficult to quantify. The first is 'spillover', where the pathogen -- a virus or parasite, for example -- passes from an animal to a person. This can be through direct transmission, for example by being bitten or by eating 'bush meat' (wild animals such as fruit bats or monkeys that are caught and consumed), or indirectly, such as through contact with faeces or disease-carrying mosquitoes. In many cases, a spillover will go no further. When a human is bitten by a rabid dog, they may become infected, but as the disease cannot transm...