Six cases of tularemia this spring and summer on Martha's Vineyard have been confirmed by the state Department of Public Health.

All six individuals who contracted the disease, who ranged in age from 33 to 67, either were landscaping or were outside near where landscaping was occurring. They contracted the potentially fatal disease by breathing in the Francisella tularemia bacterium between May 13 and July 5, health officials said.

All have been successfully treated with antibiotics for the disease, and are recovering.

The Vineyard's first tularemia case of the year, a 50-year-old male landscaper, may have contracted the potentially fatal disease after handling a dead rabbit he found while working in Edgartown, state public health officials said this week.

For the fifth summer in a row, a rare and potentially fatal disease called tularemia continues to surface on the Vineyard.

State public health officials yesterday confirmed this year's first case of tularemia: a male landscaper from Edgartown who became ill in early June. Another landscaper from Edgartown is listed as a probable tularemia case, pending follow-up blood tests.

Both men are under 30 years of age and have undergone medical treatment for the disease, public health officials said.

State public health officials yesterday confirmed this year's third case of pneumonic tularemia, the rare and potentially fatal disease that killed a Chilmark man two years ago and has baffled scientists for the last three summers.