A young research associate killed by a highly virulent strain of meningococcal disease is believed to have contracted the bacteria from the San Francisco lab where he was working on a vaccine against it, public health officials said on Thursday.

U.S. Centers for Disease Control and Prevention experts are seeking to confirm what they already suspect: that Richard Din, 25, died Saturday in an unusual case of a scientist being fatally infected with an agent from his own laboratory.

Tom Skinner, a CDC spokesman in Atlanta, said in a telephone interview the CDC in Atlanta would test a biopsy sample from Din and a sample of the laboratory pathogen he was working with to create fingerprints for each.

"If the fingerprints match, you know it's highly likely he acquired the infection from working in the lab," he said.

"Someone getting sick and dying from the organism they're working with in the lab is exceedingly rare," he added.

Meanwhile, dozens of people, including relatives, close friends, medical personnel who treated Din and some of his co-workers at the research department of the San Francisco Veterans Affairs Medical Center were being given antibiotics as a precaution.

Harry Lampiris, chief of infectious disease at the San Francisco VA, said it is likely Din died as a result of his work with Neisseria meningitidis, a strain of bacteria that causes meningococcal disease, which leads to meningitis and bloodstream infections.

"It's our responsibility to assume it's laboratory-associated until proven otherwise," he told Reuters.

Since the 1960s, vaccines have been available for some strains of meningococcal disease. But scientists in the San Francisco lab have spent more than 20 years trying unsuccessfully to develop a vaccine against serogroup B, the strain that killed Din.

"It's been like the Holy Grail to develop the vaccine against B," Lampiris said.

Din died of multiple organ failure caused by meningococcal infection and septic shock, said Eileen Shields, a spokeswoman for the San Francisco Department of Public Health. He died less than a day after becoming ill.

The disease can come on quickly with symptoms including high fever, headache, stiff neck, vomiting, rash, confusion and fatigue.

Lampiris said coworkers described Din, who began work at the lab in October, as "a very talented, hard-working and fastidious individual."

"He was a very bright person who was probably at the beginning of a long research career," he said.

Meningitis, an inflammation of the protective membranes covering the brain and spinal cord, commonly strikes infants and college students living in dormitories, Lampiris said. He said Din had not had contact with either group.

About 1,000 Americans each year suffer from meningococcal disease, and an estimated 10 to 15 percent die from it, Skinner said. He could not say how many of the cases resulted from serogroup B.

The California Division of Occupational Safety and Health is investigating the circumstances of Din's death, along with its federal counterpart and the CDC, the city Public Health Department and the San Francisco VA.