This week a property in the Tasman district tested positive for Mycoplasma bovis, the first time the disease has been found in this region.
MPI's Incident Controller for M. bovis Catherine Duthie spoke to The Country's Jamie Mackay about the latest discovery.
"The Tasman one is a trace property, it's something that we have been tracking for a while," says Duthie, who points out that the discovery is as a result of animal movement off other infected properties and therefore not unexpected.
"We're doing our best to track down all of these properties. It wasn't a surprise when this one came positive."
Overall there have been 63 properties infected with Mycoplasma bovis around New Zealand. This total is made up of 35 confirmed infected properties and 28 that have been culled and cleared so far.
The risk to neighbouring farms has been very low, with no reports of "over the fence" infection. However, Duthie reminds farmers to stay vigilant.
"Casual over the fence contact seems to be, at this point, very low risk but we would encourage people to ensure that their fencing is secure and maybe where possible maybe consider double-fencing so that there is no contact between those animals."
Another concern is that M. bovis can be spread through transporting stock, but Duthie confirms this is also low-risk and that there have been no reports at this stage.
"The highest risk by far is movement of infected animals into a herd that is not infected and allowing prolonged contact, and also the feeding of milk to calves where that milk has come from infected animals."
MPI has started spring milk testing already but Duthie says results won't be conclusive until November or December this year.