Virologist Gustavo Palacios, one of the few experts to have worked on this type of outbreak, believes the risk of spread is limited if appropriate measures are taken. He said that infected people and their contacts must be strictly traced and symptomatic patients isolated.

The hantavirus that has killed three and sickened others on board a cruise ship is believed to be a variant that transmits from human to human.

Madeleine Finlay talks to Prof Jonathan Ball from Liverpool School of Tropical Medicine to find out more about the virus behind the outbreak on a luxury cruise ship