Is PTSD Contagious?

Article here. Excerpt:

'BRANNAN VINES HAS NEVER BEEN to war. But she's got a warrior's skills: hyperawareness, hypervigilance, adrenaline-sharp quick-scanning for danger, for triggers. Super stimuli-sensitive. Skills on the battlefield, crazy-person behavior in a drug store, where she was recently standing behind a sweet old lady counting out change when she suddenly became so furious her ears literally started ringing. Being too cognizant of every sound—every coin dropping an echo—she explodes inwardly, fury flash-incinerating any normal tolerance for a fellow patron with a couple of dollars in quarters and dimes. Her nose starts running she's so pissed, and there she is standing in a CVS, snotty and deaf with rage, like some kind of maniac, because a tiny elderly woman needs an extra minute to pay for her dish soap or whatever.
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Unlike PTSD, secondary traumatic stress doesn't have its own entry in the DSM, though the manual does take note of it, as do many peer-reviewed studies and the Department of Veterans Affairs. Symptoms start at depression and alienation, including the "compassion fatigue" suffered by social workers and trauma counselors. But some spouses and loved ones suffer symptoms that are, as one medical journal puts it, "almost identical to PTSD except that indirect exposure to the traumatic event through close contact with the primary victim of trauma" is the catalyst. Basically your spouse's behavior becomes the "T" in your own PTSD. If sympathy for Caleb is a little lacking, you can imagine what little understanding exists for Brannan.'