Health agencies are working to locate and monitor people who may have been exposed to hantavirus after a deadly outbreak aboard the MV Hondius, but experts say the response is not a repeat of COVID-era contact tracing.
The immediate concern is specific: at least 30 passengers left the cruise ship when it docked at St. Helena in the South Atlantic on April 24 and later travelled onward or returned home. Officials do not yet know whether any of them were exposed, but the long incubation period of the virus means monitoring may have to continue for weeks.
The World Health Organization has confirmed the outbreak is linked to the Andes strain of hantavirus, which is endemic to Argentina and is the only strain known to spread from person to person. The MV Hondius left Argentina on April 1. Doctors and public health officials have stressed that the wider public risk remains low because spread appears to require close and prolonged contact with an infected person.
Why the tracing looks different
Contact tracing is the methodical work of identifying people who may have been exposed to an infectious disease, notifying them and watching for symptoms. In this case, investigators are likely to rely on cruise passenger records, flight information and interviews to reconstruct who had close contact with confirmed or suspected cases.
That is different from COVID-19 tracing, which was quickly overwhelmed by a highly infectious virus that could spread through shared air and eventually affected hundreds of millions of people. Dr. Anna Banerji, an infectious diseases and tropical diseases specialist at the University of Toronto, told CBC that the current outbreak requires a much narrower lens. "This is nothing like COVID," she said.
The challenge is not scale so much as time and geography. Hantavirus can take two to six weeks before symptoms appear, according to experts cited by CBC, and NPR reported that some contacts may need to monitor themselves for up to 45 days. Once passengers left the ship and boarded flights, the network of possible contacts became harder to map.
Public health specialists described the work as painstaking rather than high-tech: identify confirmed or suspected infections, sort contacts by risk and decide who needs monitoring or isolation. Because everyone can be indirectly connected to someone else through travel, officials are trying to focus on people with the highest probability of exposure rather than casting an unlimited net.
Who is known to be affected
Five hantavirus cases have been confirmed among MV Hondius passengers, including a German national and a Dutch man who died on the ship and a Dutch woman who later died in a Johannesburg hospital, according to CBC. Additional suspected cases are being examined.
More than 140 passengers and crew members from 23 countries remained aboard as the ship headed toward Spain’s Canary Islands for evacuations after being stranded for days off Cape Verde. Four Canadians were still on the vessel and had not shown symptoms, the Public Health Agency of Canada confirmed to CBC.
Two other Canadians who disembarked in St. Helena are back in Canada and isolating at home in Ontario without symptoms. A third Canadian, who was not a cruise passenger, is isolating in Quebec after coming into contact with the pair on the same flight home, Foreign Affairs Minister Anita Anand said Thursday.
Other cases and investigations have added to the international response. A symptomatic passenger from Switzerland is being treated in Zurich. Two Singapore residents who had been aboard the ship isolated at the country’s National Centre for Infectious Diseases and later tested negative. A KLM flight attendant investigated after contact with one of the Dutch passengers also tested negative. A suspected case has been reported on Tristan da Cunha, where the ship stopped on April 15.
What officials are watching now
There is no vaccine or antiviral treatment for hantavirus, so tracing and isolation decisions are central to containment. The key question now is whether anyone who left the ship — or anyone they later had close contact with — develops symptoms during the incubation window.
WHO Director-General Dr. Tedros Adhanom Ghebreyesus said the timing means more cases remain possible. "Given the incubation period of the Andes virus, which can be up to six weeks, it's possible that more cases may be reported," he said.
For now, the response is built around a narrow but urgent task: find the people most likely to have been exposed, keep them under observation and prevent any new chain of transmission from taking hold.
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