Description: Human infection with arenaviruses is incidental to the natural cycle of the viruses and occurs when an individual comes into contact with the excretions or materials contaminated with the excretions of an infected rodent, such as ingestion of contaminated food, or by direct contact of abraded or broken skin with rodent excrement. Infection can also occur by inhalation of tiny particles soiled with rodent urine or saliva (aerosol transmission). The types of incidental contact depend on the habits of both humans and rodents. For example, where the infected rodent species prefers a field habitat, human infection is associated with agricultural work. In areas where the habitat of the rodent species includes human homes or other buildings, infection occurs in domestic settings
So basically, don't eat rat poop, or in the hands of a terrorist, food contaminated with this. Of course, if a terrorist wanted to poison food to kill people, there are much more deadly, and readily available poisons that could be used.
Compared to airborne agents, VHF isn't what most people would use to kill people on a large scale.