Mr Roth said the vaccination programme may be making inroads into containing the disease, but it remained vital all those having contact with horses maintained strict biosecurity, irrespective of whether they were in a purple, red, amber, or green EI protection zone.
"We are aware that some infection has clearly been the result of human transfer of the virus," he said.
"That's why it remains vital that everyone who comes in contact with horses or horse equipment must maintain strict hygiene and biosecurity, especially when they leave a highly infectious red or purple zone.
"You need to wash or shower thoroughly and put on clean clothes before and after you have any contact with horses, ponies or donkeys to ensure you don't unwittingly transfer the virus."
Household detergents and disinfectants can easily kill the EI virus, he said.
"At the very least you should wash your hands and arms with hot water, disinfect footwear and horse gear, wash your clothes and decontaminate or wash your hat.
"And you need to ensure that any person or equipment coming onto your property has been cleared. Don't be afraid to ask people where they have been and what cleaning procedures they have followed."
Meanwhile, horse owners in the red zone around the Hunter Valley region and Tamworth district who want to move horses or equipment a short distance have been reminded they must observe current EI movement restrictions.
"Habits of a lifetime might tempt them to only go a few kilometres to a mate's place to ride or stable a horse or leave equipment, but it is imperative that zoning restrictions be maintained," said Primary Industries Minister Ian Macdonald.
"Not only must owners not move horses or equipment off their properties in the red zone, they must also not cross the line into the purple zone."
"The purple zone has been set up to enable business to continue whilst the disease burns itself out there.
"But if susceptible horses are moved into that zone, there is a risk that there will be a delay before burn out of infection occurs."
Mr Macdonald said restrictions banning the movement of unvaccinated horses into the zone came into place on November 1.
"Permits to enter the purple zone will be issued for horses that have been vaccinated twice over two weeks and have waited a further seven days, or those that have recovered from previous exposure to EI, have tested positive in laboratory tests showing immunity and have not shown symptoms for 30 days," he said.
"The existing restriction on horses leaving the purple zone remains in place.
"Our objective is to contain EI within the purple zone, while creating an environment where the horse industry can proceed with its business within the zone.
"We are hoping these measures will help clear EI from the zone but this can only be achieved if people comply with the movement, hygiene and decontamination restrictions in place.
"NSW Police and DPI Officers will be checking for illegal movements - so it is important that everyone abide by the movement restrictions - as penalties apply for those that don't.
"People should not forget that all vehicles that have transported horses within the purple zone must be decontaminated at one of these points before leaving the zone."
NSW has had 5347 properties infected by the disease, with 469 labelled "dangerous contact" and 486 "suspect".
In Queensland, 2108 properties have so far been infected with the virus, an increase of 66 since the day before.
Premises in the state currently classified as "suspect" are being re-evaluated.
As a result it is likely that the some or many of these premises will be reclassified as infected properties, so there will be a disproportionate increase in infected properties in coming days that will not be representative of the spread of infection, the Primary Industries Department said.