A Fairfax County man is undergoing treatment for rabies after being bitten by a rabid groundhog.

Brian Darby, 18, and a friend were chasing the groundhog out of a garden in Loudoun County when the animal bit Darby's hand, said his mother, Linda Hanes.

The groundhog was the first rabid one found this year in Virginia, which is experiencing its worst outbreak of rabies in more than a decade. State health officials have reported 134 cases of rabies in animals this year--almost half of them in Loudoun County.

Fairfax County health officials recorded four new rabies cases last week, for a total of 11 confirmed cases of rabies in wild animals in the county this year. They are the first reports of rabies in the county in three years.

Most of the infected animals in Fairfax have been found in the sparsely populated western end of the county. One rabid raccoon was found in Fairfax City and another in Reston last week. Earlier this year a rabid raccoon was discovered near the Arlington-Fairfax county line.

Hanes said her son chased the groundhog in the garden April 14, and the animal's teeth grazed his hand before he killed it with a rock.

Hanes said her son didn't tell her about the bite until the next day, but after he did she had him take the groundhog's head to the county health department to be tested for rabies.

The tests were positive and Darby received his first rabies vaccination injection April 19. He is to receive four more shots over a four-week period.

Darby is being treated with a new rabies vaccine that has been on the market only about a year, according to Fairfax County health officials. It replaces the painful, 23-injection treatment that has been used since the 1950s.

In an attempt to contain the rabies outbreak, health officials are urging that pet owners vaccinate both cats and dogs for rabies. Fairfax City police are asking residents to report any wild animals seen in the city.