The rabies epidemic that struck the Washington suburbs in 1983 and 1984 has moved to the east and is now concentrated in the Baltimore area and along the western shore of Chesapeake Bay, Maryland Health Department officials say.
But even though the epidemic has shifted, rabid animals are still being found in Montgomery and Prince George's counties, local health officials cautioned. For the first half of this year, there were 11 cases in Montgomery and eight in Prince George's. Two of the infected animals were cats and the rest were raccoons, the species responsible for the spread of the disease.
With 386 rabies cases confirmed this year, Maryland for the third year in a row is reporting the highest concentration of the disease in the country, followed by California and Texas, the federal Centers for Disease Control said. Nationally, rabies cases rose 11 percent in the first 20 weeks of this year. There were 5,559 cases last year, and 2,096 through mid-May this year.
Harford County, northeast of Baltimore, is the country's rabies hot spot this year, with 109 cases as of June 15, state health officials said.
"We have never had more than a handful of cases a year before this. Now, we are averaging one rabid animal a day," said Gerard Miller, director of Harford's Department of Environmental Health.
Also struck hard this year have been Baltimore County, with 63 cases, Anne Arundel County with 56, and the city of Baltimore, with 51. Baltimore County had the highest number in the state last year.
While there have been no reports of humans contracting rabies in Maryland since the epidemic began in 1981, state health officials cautioned that the disease in still in the epidemic stage and dangerous.
"We are afraid that people will become complacent because the numbers of rabies cases are decreased," said Keith Marshall, a zoologist with the Prince George's Health Department. "It is still not safe to pet a raccoon, or even go near one, and people still need to get their pets vaccinated."
The rabies outbreak started in the Allegheny Mountains in western Maryland in 1981, said Dr. Jack Grigor, an epidemiologist with the state health department. Since then, the disease has traveled eastward about 25 miles a year, carried mostly by raccoons. "The disease travels because the animals travel," Grigor said. "It is a very definite pattern, like the crest of a wave."
As the disease as spread, he said, it has depleted the raccoon population of an area, making a large-scale local recurrence unlikely. Maryland was last hit by a rabies epidemic in the mid-1950s, with most of the cases occurring in dogs.
The disease travels as far as it does in part because rabies has a long incubation period. That allows animals stricken with the disease to move about for many weeks before symptoms develop, Grigor said.
An infectious disease of the central nervous system that causes paralysis and death, rabies is transmitted primarily through the bite of a rabid animal or by saliva entering a cut or an open wound. Health officials said most human exposure to the disease comes when unvaccinated cats and dogs are handled immediately after encounters with rabid animals.
"People are afraid of wild animals, and rightly so. But what people are not afraid of, but should be, is the unvaccinated cat or dog," said Guy Hodge, a spokesman for the Humane Society of the United States.
Maryland law has long required that dogs be vaccinated against rabies, and since May 1985 has required it for cats. Prince George's County instituted the requirement more than a decade ago, and Montgomery in November 1984. Both require that dogs and cats be licensed.
Grigor of the state health department said that despite the state law, only an estimated 25 to 30 percent of cats are currently vaccinated statewide. He said that while the percentage is higher than in previous years, it is not high enough to make health officials confident that humans here are safe from the disease.
To help protect pets as the epidemic sweeps across the state, health departments have set up clinics to provide low-cost vaccinations for cats and dogs.
Harford has vaccinated more than 4,300 cats and dogs, and 89 individuals, since February, Miller said. He said most of the people were given inoculations as a precaution after handling unvaccinated cats or dogs that had been in contact with suspected rabid animals.
In Prince George's, Marshall said, more than 7,000 cats and dogs were vaccinated at clinics held in May. About 10,000 dogs and 1,600 cats are currently innoculated and licensed in the county.
In Montgomery, more than 1,200 cats and 3,000 dogs were vaccinated at county clinics from April though June, said Martha Lamborn, manager of field operations for the Department of Animal Control and Humane Treatment. About 37,000 dogs and 15,000 cats have been licensed in the past year, officials said.