GENEVA, Switzerland (AFP) — A deadly hantavirus outbreak on a cruise ship has spurred global concern over the potential spread of the virus among and from ship evacuees as they head back to their home countries.

Here are the World Health Organization’s main recommendations to limit the transmission risks and to better protect those exposed to the rare virus, which usually spreads among rodents, and for which there is no vaccine or treatment.

All of the nearly 150 people who were onboard the Dutch-flagged MV Hondius when it arrived early Sunday in the Canary Islands for disembarkation have been classified as “high-risk” contacts, according to the WHO’s epidemic and pandemic preparedness and prevention director Maria Van Kerkhove.