NSW Farmers senior policy advisor Alexandra Bunton said the risk group was expanding beyond farmers, as people were exposed to infected wild animals other than livestock.

"Since the end of the [national awareness program] there was a demonstrated drop off after that and it has slowly started to rise again," Ms Bunton said.

Q fever is a bacteria that doesn't react to standard antibiotics, it presents flu-like symptoms, can damage the liver and the heart, and, if untreated, could lead to long-term fatigue or death.

The airborne bacteria is caught from animals, mainly cattle, goats and sheep, mostly through birthing fluids or blood, with farmers and abattoir workers most at risk, although it can also be carried in dust.

Data from NSW Health showed a significant increase of cases in 2015, with 262 confirmed cases, up from about 180 the previous two years.

Braidwood farmer Owen Gwinn caught Q fever in 2005 and went through 72 hours of hell: high fevers, cold shakes and body aches before the symptoms subsided entirely.

A visit to the doctor proved Mr Gwinn had caught Q fever but he showed none of the residual fatigue symptoms.

"I'm sure there's worse. I had a whiskey when I got better, let's put it that way," he said.

Some did have it worse: Q fever put Braidwood farmer David O'Connell, 77, and his wife Janette O'Connell, 73, in hospital in September last year.

"They didn't know what was wrong with me, I was in intensive care for five days," Mr O'Connell said.

While Mr O'Connell is out of hospital, he is constantly tired, long-term fatigue being a residual effect in some cases of Q fever, and refuses to drive as he's scared he'll fall asleep at the wheel.

Figures from the NSW Southern Health District, which covers Braidwood, showed 17 reported cases in 2016, up from 10 in 2012 but a spokesperson said there was no notable rise in cases.

While 2016 showed the number statewide decrease to 225, NSW Health is trying to better understand the sharp increase in identified cases.