The disease could cause udder infections, abortions, pneumonia and arthritis.
Hastings District dairy farmer and rural community board member Nick Dawson said he was very concerned about the situation and didn't think MPI had it under control.
"I think the horse might have bolted here, I can't see them containing it at the moment but that's just my personal view," Dawson said.
"We do understand community concern about the disease and we are strongly encouraging farmers under controls or investigation to talk to their neighbours, customers and suppliers," she said.
Federated Farmers Hawke's Bay president Will Foley said he was shocked the disease had spread up north.
"It's a real bummer that this has happened and it's a shock to Hawke's Bay farmers that it landed in our patch," Foley said.
"The stock were traced in a movement from the South Island quite some time ago, connected to the Van Leeuwen group where this has all started from, but obviously the stock movement was before they were locked down," Foley said.
"So that's not a good thing that the stock have been up here for quite some time, but from what we've been told from MPI at this stage it has been contained so hopefully that is the case.
"That would be the best possible outcome from this point on," Foley said.
Geoff Gwyn from the Ministry of Primary Industries said the affected farms were quarantined.
"The Hastings and Winton properties are now under a Restricted Place Notice under the Biosecurity Act. This effectively places them in quarantine lockdown - restricting the movement of animals and other risk goods on and off the farm.
"The suspect property is under voluntary movement controls until their status is confirmed. MPI is working closely with them."
Gwyn said the ministry had not decided what would happen next.
"We're still analysing what this means for the wider response. We're dealing with a lot of uncertainty.
Foley said he expected Rural Support Trust would be offering the farmer guidance and support while MPI quarantined and locked the property down.
"Rural Support Trust will be the first port of call for the mental wellbeing of the farm affected, this is totally out of his control and his knowledge and he'll probably feeling a whole mixture of emotions," Foley said.
MPI are due to hold a public meeting in Hastings on December 20.
Dawson said he hoped he and others were expecting answers at that meeting.
He said he believed the disease had already spread through other parts of the country.
