A 22-year-old Children's Hospital worker from Prince George's County has become Maryland's 15th victim of whooping cough this year, contracting the disease after holding a 3-week-old Arlington girl who later died from the illness.

The infant was taken to Arlington Hospital June 6 when she was having trouble breathing and was transferred that evening to Children's Hospital, where her ailment was diagnosed as the highly infectious disease. The baby, who had not yet reached the standard age (2 months) for her first immunization against whooping cough, died June 8.

She became Virginia's first death from whooping cough (pertussis) in at least 10 years, said Dr. A. Martin Cader, director of Virginia's Bureau of Communicable Diseases.

The hospital employe, whom health officials declined to name, is recovering at home.

"He held her only for a few minutes," said John McAvinue, a spokesman for the Maryland Department of Health and Mental Hygiene. Whooping cough, which gets its name from the persistent cough that accompanies a high fever, is spread by airborne bacteria. The incubation period is usually seven to eight days.

Both Virginia and Maryland are reporting more whooping cough cases than usual. Maryland experienced a record 79 cases last year, none fatal, and Virginia recorded 29 cases, also with no deaths. To date, Northern Virginia has recorded eight whooping cough cases, at least twice as many as usual, said Ed Pippin, a state epidemiologist. The District reported no cases of whooping cough last year and health officials did not have figures for the current year.

"We don't know why we're having sporadic outbreaks," Pippin said, noting that immunity to the disease fades about seven years after vaccination. Revaccination is not recommended because older children and adults usually can fight off the disease and because of side effects of the vaccine.

Controversy over the safety of the pertussis vaccine, usually given in conjunction with diptheria and tetanus inoculations as a DPT booster, may have caused some dropoff in immunizations, local health officials fear.

"I'll be the first to admit it's not the best vaccine in the world, but it's the best we've got and the risk is far, far less than the disease itself," Pippin said.

Because of the highly contagious nature of the disease, public health nurses in Northern Virginia are checking all people who may have come in contact with the Arlington infant in her 25 days of life. "An adult or child could have spread it," Pippin said. "There's no way you can really guard every aspect of a newborn."

The hospitals that treated her also have taken extra precautions. The minute they diagnosed her illness,the hospital staff "went to extra lengths to treat anyone who came in contact with her," said Molly Hanson, spokeswoman for Children's Hospital.

Dr. Feng-Ying C. Lin, chief epidemiologist for the Maryland department, said he made public the Maryland case to encourage parents to arrange immunizations for their children.

"In the last decade, we routinely saw nine or 10 cases a year," said spokesman McAvinue. "Last year, we had almost 80 cases. Certainly we're worried about keeping immunization levels high among all children to keep the disease down." He noted that all local health departments will help arrange immunizations at low cost.

Children traditionally receive pertussis shots at two months, six months, 18 months and a final booster between 4 and 6 years of age.