If this story was a Hollywood movie, it might open with armed men in white hazard suits scouting a desolate Arizona suburb, with corpses of people, foxes, skunks, and bats everywhere. Cut to the edge of town, where a foam-mouthed fox with nasty intent trots crazily into the woods chasing down a small child. The hero, sensing the evil about to be perpetrated, lifts his gun and fells the fox. Wait a second! I think I’ve seen that movie!

However Hollywood might treat this subject, National Geographic reports that the U.S. Centers for Disease Control and Prevention and other health officials are taking quite seriously the fact that an evolved strain of rabies has been found in skunks and foxes in suburban areas of Arizona. The officials are concerned for two reasons. First, this strain of rabies seems to be mutating incredibly swiftly. Also, foxes and skunks have been passing the virus to their kin through simple social contact. This differs from the usual transmission method for “normal” rabies, which can only be passed from one animal to another through biting, or in rare cases, through direct contact with infected material that gets into the eyes, nose, mouth or an open wound.

According to Barbara Worgess, director of the Coconino County Health Department in Arizona, the report of the first skunk death due to rabies in 2001 was thought to be the result of a bat bite. When other skunks started expiring from rabies, health officials became concerned and initiated a skunk vaccination program. Still, more skunks turned up rabid, and the officials were puzzled. “It shouldn’t have been able to pass from skunk to skunk,” said Worgess. Later lab tests showed that the virus had become contagious within the species — that like with the common cold, just hanging out with an infected skunk put a healthy one at risk. Now CDC studies confirm that the strain of rabies showing up in skunks and foxes is a mutated version of the one commonly found in bats, a mutation that occurred very quickly. According to David Berman, the U. S. Department of Agriculture’s director for Arizona, “We’re watching evolution in action on the ground.”

The mutant rabies strain seems to be spreading rapidly, but what really has the officials nervous is the potential for it to jump species and pass on to humans. Given the mutation, you wouldn’t necessarily need to get bitten by a fox to catch the disease from him, nor would you need to bite your beloved, as in the shock horror film “Rabid”, to pass it along the human chain. According to Hinh Ly, a molecular virologist at the Emory University School of Medicine in Atlanta, this should be a “major concern.” The problem is that foxes range far and do well in habitats in and around suburban areas. Skunks commonly live under houses in these same areas. Since suburban sprawl has pushed considerable numbers of these animals into congested neighborhoods, the chances for contact between infected animals and pets and humans is real.

Of course, the disease also can be spread by bites (it is not uncommon for hikers to be attacked by rabid animals, for example). But even scarier is the fact that as more animals get infected and congregate, the possibility that the virus will mutate further increases, potentially spawning a new and more dangerous form that could spread across species.  

Officials in Arizona are on the case, trying to prevent an outbreak among pets and people. In the Flagstaff area, they declared a 90-day pet quarantine that required all dogs to be kept on leashes and all cats to be kept inside. Unfortunately, funds to vaccinate wildlife have been cut due to the recession, as have funds for public vaccination programs. Meanwhile, it’s been an active year for “normal” rabies — even in places like New York City. Recently, 39 rabid raccoons turned up in Central Park and triggered the city to begin trapping the animals and vaccinating them.

By comparison to rabies, swine flu seems like a benign illness. Rabies causes pain, vomiting, insomnia, and the famous signs of fury — thrashing, unquenchable thirst, drooling, spasms, and aggression; and once symptoms appear, death is swift. But health officials don’t expect an imminent human pandemic, because unlike flu, rabies has a very long incubation period. It typically takes 30 to 60 days from the time of exposure to arrival of symptoms, giving individuals plenty of time to get vaccinated — if they know they’ve been exposed. That’s why only about five individuals die of normal rabies in the US annually, though 18,000 get exposed and seek treatment. In other words, most people know enough to get help if exposed to rabid animals or if they receive a bite, and the current treatment works. But what if the mutant strain crosses over to humans where infection doesn’t require a bite — merely social exposure? How would you know you need to get a shot then?

Should a new strain of the disease arise, the scientists may need to go back to the lab to develop something different. Meanwhile, it’s unlikely that you’ll have to evacuate your condo unit to avoid marauding hordes of rabid skunks any time soon. But down the road may be a different story.

:hc