There are now five confirmed hantavirus cases from the Atlantic cruise ship outbreak, with three more suspected, the World Health Organization (WHO) said on Thursday, warning more cases are possible.

The WHO said it expected the outbreak on the MV Hondius, currently sailing from Cape Verde to the Spanish island of Tenerife, to be limited, so long as public health measures were properly implemented.

"So far, eight cases have been reported, including three deaths. Five of the eight cases have been confirmed as hantavirus and the other three are suspected," WHO Director-General Tedros Adhanom Ghebreyesus said.

"The species of hantavirus involved in this case is the Andes virus, which is found in Latin America," he told journalists in Geneva.

"Given the incubation period of the Andes virus, which can be up to six weeks, it's possible that more cases may be reported," he added.