Last year, a film called “[REC]” was released in Europe before making the rounds at the world’s horror festivals, thrilling audiences with its you-are-there account of a viral outbreak in an apartment building that turns people into raging maniacs. The film is viewed entirely through the lens of a TV cameraman who accompanied the fire department that responded to an emergency call at the building; “[REC]” is meant to evoke the blinking text that appears at the bottom of a video camera’s viewfinder when it’s in use. It’s the same narrative device used previously in “The Blair Witch Project,” for example, and subsequently in “Cloverfield.”

“[REC]” is a terrific horror movie, and its extremely faithful remake, “Quarantine,” is nearly as good. But why remake the film at all, especially if you’re going to follow the original so closely? Why not just release “[REC]” in the United States?

Because “[REC]” is in a different language, that’s why. Spanish, to be specific. How can America’s scare-happy young people be expected to view a film in which the actors speak in subtitles?

It’s unfortunate, but a foreign-language genre film like “[REC]” would be consigned mostly to art houses and independent theaters, and it would make a couple million dollars, tops, in the U.S. An American remake, though, has unlimited potential, and this particular remake, by up-and-coming fringe director John Erick Dowdle, is fantastically scary and intense. Disregarding its Xeroxed pedigree, it’s easily one of the best American horror films of the year. And why shouldn’t it be? It’s just like its source material, which was one of the best European horror films of last year.

Angela (Jennifer Carpenter) is the host of a TV series called “Night Shift,” in which she and her cameraman, Scott (Steve Harris), hang out with an overnight crew on some job or other; this time it’s a station of the Los Angeles Fire Department. We spend about 10 minutes following Angela as she gets to know the crew members, including the young and handsome Jake (Jay Hernandez) and the slightly older, slightly mustachioed, slightly skeevy Fletcher (Johnathon Schaech). (“I’ll bet a hundred dollars I can bed her before the night’s over,” he tells the other firemen when he doesn’t realize his microphone is on.)

But enough with the niceties. The station responds to a call at an old four-story apartment building where residents heard screams coming from an elderly woman’s flat. The firemen and the police (including one played by Columbus Short) find the woman incoherent, snarling, and dangerous. She makes her point by attacking a policeman and ripping the flesh from his neck with her teeth.

Before the emergency personnel, Angela and Scott, and the building’s residents know what’s happening, the place is locked down by the Centers for Disease Control. No one can enter or leave the apartment building, and those still inside are left to deal with the “28 Days Later”-style virus that makes its victims turn all murder-y.

And that’s basically all there is to it, plot-wise. Oh, there are some details about the cause of the virus, and some plans for escaping from the quarantined building, but you’re not interested in those. What the original directors, Jaume Balagueró and Paco Plaza, did exceedingly well, and what Dowdle expertly recreates, is the sense that the audience is part of the action. The film was shot in a real apartment building, with most of the gruesome special effects done “live,” not with post-production digital trickery. (People who know how movies are made will have a lot of “How did they do that?” moments, followed by smiling admiration for the sleight-of-hand involved.) With just one camera to shoot everything, there can be very little cutting away or editing. It feels like a suspenseful, gory version of one of those murder-mystery dinner-theater shows, where you mingle with the actors and observe the story unfolding all around you.

The screenplay (credited to Dowdle and his brother Drew) seems to allow for some improvisation among the actors, which contributes to the film’s natural, believable tone. But a few scenes are marred by unconvincing histrionics, the sort of shrieking where it sounds like the actor is guessing at what a frightened person would say and can only come up with what he or she has seen other movie characters do.

As for why Scott keeps filming even when his life is in peril — well, that’s always the question in these first-person movies, isn’t it? I guess you just have to accept it as part of the film’s concept. In Scott and Angela’s view, the camera is a weapon — literally, at one point — and the only way to document the egregious offenses committed by the entities that quarantined the building and gave up on its occupants. If Scott hadn’t kept filming, we’d never know what happened to these people! What’s more, we’d be denied the funhouse chills that come from seeing the disaster unfold in a confined space. Bodies dropping from upper-story landings, savages leaping from darkened corridors, a rabid German shepherd in an elevator — this is a recipe for good old-fashioned terror, no matter what language it’s in.

B+ (1 hr., 29 min.; R, a lot of harsh profanity, a lot of very bloody violence and gore.)