Now Is the Critical Moment to Stop the Spread of Hantavirus — Why?

MV Hondius, a cruise ship carrying passengers from dozens of countries, has been struck by an Andes hantavirus outbreak. The strain, which carries a case fatality rate of about 40%, represents the first major test for global health authorities in containing transmission since the COVID-19 pandemic. Countries are adopting varying strategies to monitor potentially exposed passengers and curb spread while addressing public concern.

Infectious disease experts say those on board from early May are now entering the most likely window for symptom onset. Dr. Isaac Bogoch, an infectious diseases specialist at the University of Toronto, noted that the incubation period is typically around three weeks, but monitoring may continue for up to 42 days (six weeks) to ensure safety. The most recent case on the ship was a German passenger who died on 2 May, the same day researchers identified the cause of infection. Because Andes virus is transmissible between humans, the main challenge is to ensure every exposed individual adheres to health protocols.

Countries have taken diverse approaches to the ship’s return. The timing of testing has been a major debate; Dr Bogoch emphasised that routine PCR testing is vital because the virus can spread 5 to 10 days before symptoms appear. The US CDC currently only recommends testing if symptoms are present. ‘Relying on symptoms alone means you will miss many people,’ Bogoch said. Early testing is crucial since, although there is no specific antiviral treatment for Andes virus, there are three antivirals shown to be effective if given early.

Transparency of information is also being scrutinised. In France, Health Minister Stephanie Rist held an open briefing with virology experts. By contrast, in the United States, CDC briefings have been more succinct and offer fewer specifics about passengers’ conditions, citing privacy.

Health authorities worldwide are racing against time. With some passengers having evaded initial surveillance and boarded international flights, the risk of secondary spread remains a real concern for the World Health Organization. Belarus reports an average of 50 hantavirus cases per year with HFRS symptoms; readers are invited to consider this link to the ship’s outbreak. The WHO says there have been no new deaths from the ship-related hantavirus outbreak. The Indonesian Health Ministry has prepared 51 Balai Kekarantinaan Kesehatan (BKK) to prevent Hantavirus spread. Evacuations to the Netherlands continue as two final flights carrying passengers and crew landed at Eindhoven Airbase. Australia has confirmed six aboard the Hondius with hantavirus are in stable condition and will undergo strict quarantine for up to 42 days to prevent further spread. If an Andes strain is identified, patients must be isolated to prevent wider transmission.