Let's assume you get transported to the worst possible starting location, Muenzukan. From there you must travel down the Road of Reconsideration and through the Forest of Magic to finally arrive in the Human Village.

Muenzukan and the Road of Reconsideration are notable for their many ghosts. In Perfect Memento in Strict Sense, ghosts are stated to be extremely dangerous with any touch from them "beckoning death,". Many ghosts do not realize they are dead. While there are also dangerous youkai who stalk these areas in hopes of finding an outsider to eat, the ghosts are dangerous to them as well so there will only be so many.

Invoking the Taoist diety Zhong Kui could protect one against these ghosts. Ghosts are also weak to all parts of the peach tree. https://en.wikipedia.org/wiki/Zhong_Kui

Ghosts are stated to be indistinguishable from humans to the untrained eye. But there may be ways for the trained eye to identify them. Many cultures have believed dogs to be capable of seeing ghosts and other spiritual entities. The Aztecs even believed that if you rubbed a dog's eyes and then your own with the same fingers, you would gain the ability as well. In this situation I'd imagine the risk of getting killed by a ghost outweighs the risk of infection.