US CDC reportedly classifies hantavirus outbreak as level 3: What does this say about severity of the outbreak

The US Centers for Disease Control and Prevention has classified the hantavirus outbreak tied to a cruise ship as a "Level 3" emergency response.The outbreak started aboard the MV Hondius, a cruise ship that departed Argentina in March and picked up passengers from around the world. By May, the World Health Organization (WHO) confirmed five infections tied to the ship, with three deaths reported. More than 100 passengers remained onboard as of Thursday, with doctors added to the ship and health authorities in at least a dozen countries now monitoring passengers who've scattered across the globe after disembarking.According to ABC News, which first reported the CDC's Level 3 classification, the agency is responding to what's described as a rare and unusual situation. The outbreak is considered noteworthy precisely because hantavirus cases aboard a cruise ship traveling internationally are genuinely uncommon"There may be some person-to-person spread," health officials cautioned, which is the part that got everyone's attention. Hantavirus is typically transmitted through contact with infected rodents or their droppings, so the possibility of human-to-human transmission on a cruise ship raised immediate concerns. But even with that caveat, officials have been consistent in their message that this isn't a widespread threat.The CDC has four levels of emergency activation, with Level 1 being the highest response. A Level 3 classification means the agency is coordinating across different departments and activating resources, but it's not what you'd call an all-hands-on-deck situation. It's acknowledgment that something abnormal is happening and requires tracking, but it's not suggesting an imminent crisis.Health officials in multiple US states are monitoring passengers who've returned home after being aboard the ship, but there's been no indication of a secondary outbreak among the general population.CNN reported that from the US to Singapore, health authorities are working to trace the movements of people who were on the cruise. One passenger, Kasem Ibn Hattuta, told ABC News that the vibe on the ship has remained relatively calm despite the situation. "Everyone is keeping high spirit[s], people are smiling and taking the situation calmly," he said, noting that the addition of several doctors onboard was reassuring to passengers.The ship itself is expected to dock in Spain's Canary Islands, where Spanish authorities have already prepared for its arrival.