Lyme disease cases increased 101% between 1992 and 2006

More than 248,000 cases of Lyme disease were reported to the CDC between 1992 and 2006, according to recently released data.

Although the number of reported cases varied from year to year, health officials said the “overall trend indicated a steady increase” in the number of reported cases during a 15-year period. In 1992, there were 9,908 reported cases of Lyme disease. By 2006, there were 19,931 reported cases, a 101% increase.

The new data indicated that the distribution of cases remains highly focused. Ninety-three percent of all cases were reported in ten states: Connecticut, Delaware, Massachusetts, Maryland, Minnesota, New Jersey, New York, Pennsylvania, Rhode Island and Wisconsin. The most significant increase in the number of cases was seen in Minnesota, Pennsylvania and Wisconsin.

CDC officials said the new data “underscore the continued emergence of Lyme disease and the need for tick avoidance and early treatment interventions.” CDC officials also stressed the need for improved prevention and treatment strategies and a sustainable surveillance system. – by Jay Lewis

MMWR. 2009;57:1-9.

As with many emerging zoonoses, a rapidly changing environment fostering increased enzootic transmission of a pathogen combined with human encroachment into this environment have produced a nearly monotonic increase in annual Lyme disease incidence extending now for nearly three decades. Since human population growth and suburbanization as well as the underlying environmental changes that have produced exploding deer and deer tick populations are likely to continue unabated, we can expect that Lyme disease incidence will likely increase for the foreseeable future.

– Lyle Petersen, MD, MPH

Infectious Disease News Editorial Board member