Ashley Falls, MA (The Berkshire Eagle)-- Sales at a small dairy here have been halted while state health officials investigate the possibility that its raw milk may be contaminated with a rare, infectious bacteria.

The Department of Public Health is investigating the first human case of brucellosis in more than two decades after Robert Kilmer, the owner of Twin Rivers Farm, was diagnosed with the bacterial infection last week.

Until testing of his farm’s herd and milk is completed, the state is asking consumers to discard any milk from Twin Rivers they may have on hand. The milk, which is unpasteurized, is only available for sale at the Rannapo Road farm and isn’t distributed in stores.

Although the Department of Public Health strongly implicated Twin Rivers’ milk in a recent consumer alert, Kilmer doubts his product is to blame.

He says his herd has been vaccinated for brucella and he hasn’t heard of any of his customers becoming ill. "So far, customers I’ve been in contact with are fine and none of my family have it, and they drink more milk than I do," said Kilmer. "I’m almost intrigued by it now, because there’s no way it should be in my herd."

Kilmer said he only sells about 22 gallons of raw milk a week. Most of his product -- his herd produces more than 680 gallons a week -- is taken off site and pasteurized, which health officials says kills the bacteria in question.

Local raw milk advocates questioned health officials’ focus on Kilmer’s milk as the cause of the outbreak.

"There’s just a knee-jerk reaction on the part of health inspectors -- as soon as they hear raw milk [was consumed], they stop listening to anything else and assume that’s what the problem is," said Winton Pitcoff, the coordinator of the Raw Milk Network of the Northeast Organic Farming Association’s Massachusetts chapter.

Pitcoff said he understands the need to err on the side of caution when it comes to public health threats, but he said the alert distributed by state officials could damage a local farm even though there’s no evidence it’s the source of the problem.

"It’s kind of like guilty before proven innocent," said Pitcoff.

But the Department of Public Health says the presence of brucella in raw milk represents a serious danger.

The early symptoms of brucellosis are similar to the flu, including fever, sweats, headaches, swollen lymph nodes, back pains and physical weakness. Severe infections of the central nervous systems, bone or heart may occur.

The bacterial infection can also cause long-lasting, chronic symptoms, according to health officials.

Kilmer, who first became ill in late last month, was surprised when his doctor finally suggested a test for brucellosis.

"I thought it was foolish because I was under the impression we’d eradicated it years ago," he said.