How some exposure to Ebola could lead to immunity

Epidemics like the current Ebola outbreak in West Africa often get started when people make contact with animals carrying infectious diseases, but, paradoxically, a certain amount of human exposure to a virus at its source can actually also prevent the extensive spread of a disease, new research suggests. Finding a “sweet spot” – where there is enough human contact for some people to build immunity to a virus, but in a way that does not cause a disease to spread widely, could be a key to preventing deadly diseases from becoming epidemics, researchers say. “If we’re really worried about emerging infectious diseases, we really need to pay attention to the ecological interfaces between animal reservoirs and the human populations that interact with them,” said Timothy Reluga, a mathematical epidemiologist at The Pennsylvania State University. Infectious diseases such as Ebola hide out within animal populations. Scientists call these populations “reservoirs,” and contact between humans...