If you catch hantavirus on a cruise, the cruise line probably doesn't owe you a cent — here's why

Meanwhile, 17 American passengers were flown to the federal biocontainment unit at the University of Nebraska Medical Center (4). The CDC has ordered them to quarantine there for up to 42 days — the maximum incubation window for the virus.

This is the first case of Andes hantavirus (5) on the ship, according to the World Health Organization (WHO) (6). It is suspected to have come from "exposure to rodents during bird watching activities" before the cruise even began.

A Dutch couple who took a pre-cruise trip (7) through Argentina, Chile and Uruguay are believed to have brought it aboard.

That detail will haunt any thought of seeking damages, but so will the broader truth about cruise liability. Maritime law, a 1991 Supreme Court ruling and fine print on every cruise ticket make it nearly impossible for sick passengers to recover meaningful compensation from a cruise line.

Why the Hondius outbreak is a worst-case scenario for plaintiffs

The Hondius is registered in the Netherlands (8), owned by an Amsterdam-based company and did not touch a U.S. port on this particular voyage. Those three facts mean American maritime case law plays a smaller role than usual.

Instead, the controlling framework is likely an International Maritime Organization treaty known as the Athens Convention relating to the Carriage of Passengers and their Luggage by Sea (9).

According to its 2002 Protocol (10), ratified by the Netherlands, passenger compensation is split into two categories:

• Shipping incidents, including shipwrecks, fires, capsizings, collisions, defects in the vessel — which trigger strict liability up to 250,000 Special Drawing Rights per passenger (11), converted into local currencies depending on the parties involved

and

• Non-shipping incidents, basically everything else — including viral outbreaks — where to receive any payout, passengers must prove the cruise line acted negligently. That's tough if it's an infectious disease with a one-to-eight-week incubation period (12) that likely originated off the ship.

Hantavirus spreads almost exclusively through contact with rodent urine, droppings or saliva. When it spreads between people, it requires close, prolonged contact. Establishing that Oceanwide failed to act reasonably — rather than that unlucky passengers brought a virus aboard from the Patagonian backcountry — would be a plaintiff's mountain to climb.

Oceanwide has been publishing detailed press updates throughout the crisis (13) and coordinating with health authorities, the kind of paper trail that tends to insulate carriers from negligence claims.

The 1991 Supreme Court decision that rewired cruise lawsuits

Even when a cruise originates in a U.S. port and U.S. courts have jurisdiction, the deck is stacked against passengers.

The pivotal precedent is Carnival Cruise Lines v. Shute (14), decided 7-2 by the Supreme Court in 1991. Washington state resident Eulala Shute sued Carnival in her home state after she slipped on a deck mat aboard a Carnival cruise off the Mexican coast.

Carnival pointed to fine print on her ticket requiring disputes to be filed in Florida, and the judge sided with Carnival.

That ruling reshaped the entire industry. Major cruise lines today require passengers to file suit in a specific federal court — typically the Southern District of Florida for Carnival, Royal Caribbean and Norwegian (15) — within one year of an incident, with written notice provided within six months. And the standard of care isn't passenger-friendly either.