Antibiotics and vaccines are being offered to about 80 people in the state of New Hampshire as authorities investigate America's first known case of gastrointestinal anthrax.
Officials still don't know how the woman contracted the disease but are focusing on a drum circle gathering she attended last month. She was diagnosed Saturday.
Officials have shut down the United Campus Ministry center in Durham, where anthrax spores have been found on two drums and an electrical outlet. They said Tuesday that vaccines and antibiotics will be available to people who attended the event or live or work in the building.
Dr. Elizabeth Talbot, an adviser to the state's public health division, says one theory is that the spores became airborne through vigorous drum playing, and the woman swallowed them.