It’s been more than a decade since Dr. T.K. Lee, a microbiologist at the Maine Health and Environmental Testing Lab, taught me to see the raccoon rabies virus as a wave of sickness, death and fear engulfing towns and counties one by one.

This strain of rabies began spreading rapidly along the Eastern Seaboard in the 1980s. The first infected skunk was found in Eliot in 1994 and the first two cases in Aroostook County were reported in 2007. This spring a rabid fox bit a dog in Masardis, which is about 10 miles south of Ashland. That’s the farthest north that raccoon rabies has been found in Maine.

Now that spring is here and Maine's wildlife is active again, rabies is on the move again, although it moves more slowly in rural areas. The number of infected animals statewide peaked at 248 in 1998. Last year there were 71 and there have been 20 cases so far this year, most in southern to central Maine, according to a recent press release from the Maine Department of Inland Fisheries and Wildlife. 

This epidemic has taken a great toll on wildlife, but not people, although a number have had to take shots, which, while not as painful as in the past, are still no picnic and cost about $2,000. People are usually exposed to the deadly virus through their pet's saliva or when they mistakenly try to help a sick animal and are bitten. Once a person’s central nervous system is infected, rabies is fatal, but human fatalities are very rare in the United States. In fact, the number of rabies-related human deaths in the United States has declined from more than 100 annually at the turn of the century to one or two per year.

Since 1994, more than 1,700 animals have tested positive in Maine. Around half have been raccoons, but the raccoon rabies strain also has been found in skunks, foxes, coyotes, woodchucks, beavers, dogs, cats, even horses. The number of positive tests just hints at the epidemic's toll, however, because animals are tested only if they came into contact with domestic animals or people. Countless other rabid animals have died in the wild or been killed by animal control officers, law enforcement officers or others.

The Masardis dog bitten by the fox was up to date on the rabies vaccination and no human exposure occurred. If a pet has been vaccinated for rabies, it needs only a booster shot and 45 days in quarantine. Unvaccinated pets that have been exposed to a rabid animal must be held in strict isolation for six months and are euthanized if they show signs of the disease.

The highest number of cases occurred when the epidemic passed through Maine’s most populated areas because raccoons and other frequently affected animals, such as skunks, thrive in suburban areas where the human population provides a ready supply of food — garbage. As a wild population rebounds, rabies infects the young animals, but usually the outbreaks are much less severe than the first one.

“What happens is that in the first couple of years, it probably infects and kills the overwhelming majority (of wild animals), maybe up to 80 percent of the population. Then, it drops, and it has to sort of build up again.” Dr. Lee said.

Cumberland County had the most cases in the state in 1996 and 1997 (52 and 76). Then Somerset, Waldo and Penobscot took over the top spots through 2000, until the second wave put Cumberland back on top until from 2001 through 2003. Since then the counties with the most cases have been Kennebec (16) in 2004; Franklin (11) in 2005; Penobscot (17) in 2006; Androscoggin (15) in 2007, and Kennebec (13) in 2008.

It also helped to slow the spread when the Canadian and U.S. governments joined in 2003 to drop vaccine-laced baits (harmless to people and pets) from planes. The packets also contained tetracycline to mark the teeth of the raccoons that ingested them so officials could later determine which animals had eaten the bait.

Researchers spent six weeks live-trapping raccoons in Penobscot, Aroostook and Washington counties to collect blood and tooth samples for testing, the Portland Press Herald reported in 2004. The samples showed 70 to 80 percent of the raccoons tested ate the fishmeal bait laced with vaccine and developed antibodies to the rabies virus.

Yet though the number of cases has certainly dropped this decade, rabies remains a serious threat. The best protection is to keep pets up to date with rabies vaccinations and people should never feed, touch, or adopt wild animals. It’s also important to be cautious of stray dogs and cats.
 
This epidemic isn't over and isn't likely to be. Nine years ago, Charlie Taylor, who was Orrington's animal control officer, was hoping the Penobscot River would protect his town, but he hoped in vain. The epidemic jumped the Penobscot, just as it had the Androscoggin, the Kennebec and other rivers.

“We were pretty sure it wouldn't come across the river,” Taylor said, “and the next thing we knew it had.”
                  

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