UPDATE, 2.45pm: It was "extremely lucky" there were two grown men at the Evans Head Skate Park to pull off an infected bat which had begun "gnawing" at a boy's leg.

The boy has started a round of vaccines issued by Public Health and the bat has since tested positive for the potentially deadly lyssavirus at the Department of Primary Industry's Sydney laboratory.

Isaac Roxburgh, proprietor of Nan and Pop Skate Boutique and the bat victim's uncle, saw the dramatic event unfold.

"A bat came from nowhere," he said.

"It seemed to come really low.

"Then it came back and swooped at my niece.

"I stood with the kids and then it came back for me.

"I crouched down and knocked it away with my skateboard.

"Then when I was protecting the kids it came back for my sister-in-law who is pregnant."

The bat came to the ground and attached itself on to the boy's leg.

"It latched onto the boy's calf immediately and just started gnawing at his leg," Mr Roxburgh said.

"His dad acted quickly and grabbed the cap from his head and started pulling it off. It (the bat) was on really tightly. It took two adult males to pull it away.

Mr Roxburgh emphasised he hadn't seen this level of aggression from a bat near the skate park.

He said he wouldn't stop using the skate park but said: "I'd say if you see a bat flying low, keep away.

"It would have been a lot worse if he wasn't wearing very thin tracksuit pants.

"It's the first time I've seen anything like it. "

ORIGINAL STORY: A HIGHLY aggressive fruit bat infected with the potentially deadly lyssavirus attacked a boy at the Evans Head Skate Park last week.

According to reports from witnesses to the attack, the bat wouldn't let go of the boy's leg and had to be bashed off by others.

It will be an anxious fortnight for the boy's family as they wait to see if he has been contaminated with the virus.

According to Public Health acting director Greg Bell, a special vaccine had to be flown up to the boy soon after the attack on Thursday.

All the correct protocols were followed and this should ensure an "excellent outcome".

He said there has been no recorded cases of anyone succumbing to lyssavirus after starting the vaccine course within 48 hours.

Mr Bell said a "very capable" local GP is administering the vaccine and monitoring the boy.

He explained there was no way of finding out whether the boy had succumbed to the disease until symptoms were present. These usually present 12 to 14 days after an attack.

Mr Bell said Public Health receives two to three potential lyssavirus cases per month, however it was rare for the bat to be captured and tested, let alone come back positive. The boy started the vaccine course before the bat results came back positive.

According to a second-hand witness account , the bat was 'aggressive'' and wouldn't let go of the boy's leg until it was 'bashed off' by others.

Mr Bell conformed the bat was 'agitated', behaviour which indicated the bat was carrying the lyssavirus.

"I can't stress enough the importance of acting quickly to prevent succumbing to the virus. Otherwise you are just plating Russian Roulette. Once you contract the virus there is no cure."

"In this case the correct protocol was followed but I understand it is an anxious time for the family," he said.

Mr Bell gave the following advice for anyone bitten or scratched: