New England has been put on high alert thanks to an outbreak of Eastern Equine Encephalitis (EEE), a rare virus that can lead to the deaths of 30% of those infected, and leave many survivors with neurological problems. Despite the name, (the second E, equine, means "horse") this virus is spread by mosquitos, an example of what is known in the medical field as a disease vector. In today's post, we'll look at what a vector is, and how they play a role in the spread of healthcare-associated infections.