MV Hondius hantavirus outbreak spreads

The World Health Organization said on May 13 that 11 cases linked to the cruise ship MV Hondius had been reported across multiple countries, including eight laboratory-confirmed Andes virus infections, two probable cases and one inconclusive case. Three deaths had been reported by that date, and WHO said all confirmed cases were passengers from the ship. The outbreak has drawn attention because the virus was identified as Andes hantavirus, a strain for which human-to-human transmission has been documented, though health agencies say the broader public risk remains low. The CDC said the risk to the United States public is “extremely low,” and ECDC said the risk to the EU/EEA general population remains “very low.” The ship was on a voyage that departed Ushuaia, Argentina, on April 1 and later traveled through Antarctica and remote South Atlantic stops before the illness cluster was reported to WHO on May 2. (who.int) CDC said 147 people — 86 passengers and 61 crew — were onboard from 23 countries. ### How broad is the outbreak now? WHO said the count stood at 11 cases as of May 13, with three deaths, after additional confirmed cases were reported from France and Spain and one inconclusive case was identified in the United States. (cdc.gov) ECDC said on May 16 that no new cases or deaths had been reported since its previous update. France’s Institut Pasteur said five French passengers returned to France and were hospitalized in quarantine at Bichat Hospital in Paris after disembarkation in the Canary Islands. (cdc.gov) The institute said it is receiving samples from symptomatic people in France for analysis through the national reference center for hantaviruses. (who.int) ### What did French sequencing show? The Associated Press reported on May 17 that France’s Pasteur Institute had fully sequenced the virus from a French passenger and found that it matched known South American Andes virus lineages rather than showing evidence of a new variant. CBS News, citing French officials, reported the genomic analysis showed no evidence of new characteristics so far. (pasteur.fr) Institut Pasteur said on May 12, updated May 15, that South African sequencing on May 6 had already identified an Andes-type strain. The institute said Andes virus is the only known hantavirus strain among the recognized hantaviruses for which human-to-human transmission has been documented, while adding that rodent exposure remains the main route of transmission. (apnews.com) ### What is happening in the United States? The CDC said on May 8 that it had deployed epidemiologists and medical staff to the Canary Islands and planned to support repatriation of American passengers to specialized facilities in Nebraska. The agency said its team would assess each passenger’s exposure risk and recommend the level of monitoring required. (pasteur.fr) Reuters reported on May 14 that 41 people in the United States were being monitored for possible infection, including 18 quarantined in Nebraska and Atlanta, and that there were no confirmed U.S. cases. CDC’s situation page also says the risk of broad spread in the United States is considered extremely unlikely. (cdc.gov) ### Do officials know where the outbreak started? WHO said its working hypothesis is that the first case acquired the infection before boarding the ship through exposure on land. The agency said investigations with authorities in Argentina and Chile were continuing to clarify the source and circumstances of exposure. That leaves two overlapping lines of inquiry: where the initial infection occurred and how much subsequent transmission, if any, took place among passengers. (usnews.com) WHO and ECDC have both said international contact tracing is continuing through national health authorities. ### What comes next for passengers and health agencies? ECDC said its outbreak page is updated once daily, including on weekends, and listed guidance issued on May 14 and May 15 covering laboratory testing, passenger management and infection prevention in healthcare settings. (who.int) WHO said it would continue to monitor the epidemiological situation and update its risk assessment as needed. CDC said affected Americans had received health guidance through the State Department and that state and local health departments were receiving monitoring guidance as well. The next public milestones are likely to come through updated WHO, ECDC and CDC outbreak pages as retesting and contact follow-up continue. (cdc.gov) (ecdc.europa.eu)