A frustrated WA health minister told the Commonwealth to "get off their butts" and protect Australia's trade routes as he fronted the media to announce the outbreaks on Saturday.

"Dealing with this is out of the control of the WA government," Roger Cook said.

"This is where the federal government must get involved to do what it can to help these situations and stop them occurring in the future."

A crew member of the Key Integrity docked at Geraldton has tested positive as well as a crew member of the Al Messilah, docked at Fremantle.

Outbreaks have been declared for both and response teams dispatched.

The Al Messilah crew member was only tested as a precaution when taken off the ship for unrelated medical care at Fiona Stanley Hospital, though PPE was worn by staff at all times, Mr Cook said.

The crewman is now in hotel quarantine.

However, crew members from three other vessels were transported in the same bus as the Al Messilah man, prompting the need for public health officials to interview them because there had been "some" interaction.

The cases will be counted as part of the state's Sunday tally.

Mr Cook said the recurring nature of the foreign outbreaks off the WA coast was "immensely frustrating".

"It's important for the commonwealth government to actually get serious with these other countries that are sending unwell crew members," he said.

Mr Cook said the health ministers of Queensland and New South Wales and also expressed concern about trade ships coming into Australian waters with infected crew.

WA has already managed four outbreaks onboard the Artania, Al Kuwait, Patricia Oldendorff and Vega Dream.

The new cases mark the fifth and sixth vessels the government must manage.

"The community has remained safe during each of these operations, with no risk to public health," WA Health said in a statement on Saturday.

"The same processes will be used for the Key Integrity and Al Messilah, as well as any future vessel outbreak."

No port in WA is allowing shore-leave for any international maritime crew.

"This means that no-one can disembark a vessel - expect for medical treatment - whereby appropriate safety procedures are put in place," WA Health said.

The Key Integrity case was confirmed after a nurse in full PPE entered the vessel to obtain the swab from the crew member, who is no longer exhibiting symptoms.

Meanwhile, on the issue of potentially creating a travel bubble with other Australian states, Mr Cook said his government's hard border policy had kept West Australians safe.

"If we open up our border to South Australia we essentially cede control of our borders to the south Australian government ... and that's not good enough," he said.

Earlier on Saturday, the state recorded two new cases, both in travellers in hotel quarantine.

Australian Associated Press