New species of bacteria found to cause Lyme disease

BOSTON — A new species of bacteria is causing Lyme disease, adding to worries that the infection will continue its relentless escalation across the United States. Lyme is already the most common tick-borne disease in North America, with new cases peaking every June and July.

“In summary, the news is largely bad,” Paul Mead of the U.S. Centers for Disease Control and Prevention said June 19 at a joint meeting of the American Society for Microbiology and the Interscience Conference on Antimicrobial Agents and Chemotherapy. Not only is the prevalence of Lyme disease increasing, another tick-borne illness — Rocky Mountain spotted fever — is cutting a deadly path through Mexico.

Public health officials began collecting data on Lyme disease in 1991. Since then, it has spread in all directions from