Andes hantavirus sickens 11 passengers

European and U.S. health authorities have converged on a narrow message about the Andes hantavirus outbreak tied to the cruise ship MV Hondius: the cluster is serious, but officials do not see it as the start of a broad public-health emergency. The European Centre for Disease Prevention and Control said on May 20 that 11 cases had been reported, including 9 confirmed and 2 probable, with three deaths. (ecdc.europa.eu) CIDRAP reported on May 21 that detailed information had been released on 10 of the 11 cases, including the first passenger believed to have been infected after the index patient. (cdc.gov) CDC said on May 19 that no cases linked to the outbreak had been confirmed in the United States. ### How large is the outbreak now? The ECDC said the total stood at 11 cases as of May 20, and that no new cases or deaths had been reported since its previous update. The agency said the patients were linked to the Dutch-flagged MV Hondius, which carried passengers and crew from 23 countries. WHO said the outbreak first came to its attention on May 2, when it was notified of a cluster of severe respiratory illness aboard the ship. In its initial account covering the situation as of May 4, WHO said seven cases had been identified, including three deaths, showing how the count rose as tracing and testing continued. (ecdc.europa.eu) ### Why are officials focused on one later passenger infection? CIDRAP said the newly released case details included the first passenger infected after the index patient, a point that matters because Andes virus is unusual among hantaviruses in having documented, limited person-to-person spread. WHO said such transmission has been reported in previous Andes virus outbreaks, though human infection is primarily acquired through contact with infected rodent urine, feces or saliva. (ecdc.europa.eu) CDC said on May 8 that clinicians should be aware of the potential for imported cases, but that broad spread in the United States was “extremely unlikely” at that time. The agency issued that advisory to public health departments, laboratories and healthcare workers as passenger monitoring widened. (who.int) ### Where did the ship travel, and how might exposure have happened? WHO said the vessel departed Ushuaia, Argentina, on April 1 and traveled across the South Atlantic with stops including Antarctica, South Georgia, Tristan da Cunha, Saint Helena and Ascension Island. The agency said the extent of passenger contact with wildlife before or during the expedition remained undetermined. (cidrap.umn.edu) OSF HealthCare cited Sharjeel Ahmad, an infectious-disease physician, as saying passengers likely had environmental exposure during shore excursions in rodent habitats, including hiking, visiting rural structures and exploring wilderness areas. Ahmad said the Andes strain’s reservoir was reported to be the long-tailed pygmy rice rat, found in parts of Chile and Argentina. (cdc.gov) ### What is happening with U.S. passengers? CDC said 18 passengers who remained on the ship were repatriated on May 10 and taken to the Nebraska Quarantine Unit at the University of Nebraska Medical Center for monitoring over 42 days. The agency also said seven passengers who returned earlier were being monitored at home by state and local health authorities. (who.int) OSF HealthCare said on May 18 that dozens of patients in the United States were still receiving treatment or remained in quarantine. The health system also said one Illinois case under investigation was not connected to the cruise ship outbreak and later tested negative, citing the Illinois Department of Public Health and CDC confirmation. (newsroom.osfhealthcare.org) ### How worried are experts about a wider outbreak? CDC said on May 19 that the risk of a pandemic caused by this outbreak, and the overall risk to the American public and travelers, was “extremely low.” ECDC separately said the risk to the EU/EEA general population remained “very low.” OSF HealthCare quoted Ahmad describing concern about a pandemic threat as “very, very low.” A public-radio report based on NPR’s May 21 reporting said infectious-disease experts do not expect Ebola or hantavirus to become another COVID-scale pandemic, even as post-COVID experience has made some Americans more alarmed by such outbreaks. (cdc.gov) ### What comes next in the response? (newsroom.osfhealthcare.org) The MV Hondius has been docked in Rotterdam since May 18, and ECDC said ship sanitation is being carried out there. The agency said additional cases among former passengers and crew are expected to be identified after they returned home because Andes hantavirus has a long incubation period and some infections may have occurred on board. (cdc.gov) CDC said its outbreak page will continue to be updated as the situation changes, and ECDC said its own page is updated once daily, including weekends. U.S. monitoring of exposed passengers is continuing through the 42-day observation period, with CDC working alongside state, local and international public-health partners. (newsroom.osfhealthcare.org) (cdc.gov) (ecdc.europa.eu)