NEW YORK (AP) — Hantaviruses do not spread easily between people, which makes health officials confident the recent outbreak on a cruise ship that has killed three people will not turn into an epidemic. But, still, they need to make sure. So health officials in several countries are contact tracing: trying to identify and follow people who may have come in contact with passengers who got sick or died. Hantaviruses usually spread when people inhale contaminated residue of rodent droppings. While human cases are rare, small outbreaks have been documented around the world. But the Andes virus implicated in the cruise ship outbreak may be able to spread between people in rare cases. And viruses can change. Scientists are trying to learn more about the virus as fast as they can, including whether it has mutated and how exactly it spreads. What is contact tracing?…