India, May 7 -- A deadly hantavirus outbreak aboard an Antarctic cruise ship went undetected for weeks before health authorities confirmed the rare Andes strain was spreading among passengers, raising fears of possible human-to-human transmission.

The outbreak has been linked to the cruise liner MV Hondius, which departed from Argentina for Antarctica on April 1. Three passengers have died, while several confirmed and suspected cases have been tied to the vessel, according to a BBC report.

Hantavirus spreads by inhaling contaminated rodent droppings and can spread from a person but it is rare.

The first death on board was reported on April 11, when a 70-year-old Dutch man died, according to the World Health Organization (WHO). His 69-y...