A rare bacterial infection called tularemia that killed a Chilmark man three years ago appears to have hit the Island for the fourth summer in a ro

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.

A second round of blood tests has confirmed that two Island men who fell ill earlier this month with symptoms of pneumonia actually had the pneumonic form of tularemia, the rare bacterial disease that killed a Chilmark man almost two years ago.

The Harvard scientists who spent the last four days on the Vineyard collecting clues that could help them solve the Island's biggest medical mystery came armed with an unusual tool kit: an aerosol can of automotive starter fluid, two flowerpots painted blue, a bag of apples and an empty can of Diet Coke.

Suspicions that tularemia has made a comeback on the Vineyard for the third summer in a row have prompted a series of new health advisories aimed at the group of people at highest risk for the disease - landscapers.

From the start, scientists have viewed the outbreak of tularemia on Martha's Vineyard as an ecological puzzle, never a case of bio-terrorism, despite tularemia's recognized status as a bacteria ideally suited for terrorism.