WHO Disease Outbreak News 599

WHO Disease Outbreak News 599 (DON 599) is a WHO Disease Outbreak News bulletin published on 2 May 2026 covering the hantavirus cluster associated with the MV Hondius cruise ship. Disease Outbreak News (DON) is WHO's public bulletin series for confirmed or potential outbreaks of international public health concern. Published by the WHO Health Emergencies Programme, DONs present case counts, geographic scope, source data, and a formal WHO risk assessment. They are the primary mechanism through which WHO communicates outbreak status to the public and to national health authorities. DON 599 logged 7 cases (2 lab-confirmed, 5 suspected), 3 deaths, 1 critically ill, covering passengers and crew from 23 nationalities, with the vessel having departed Ushuaia on 1 April (a date that later conflicted with the Africa CDC account of 20 March).

DON 599, published 2 May 2026, treated the MV Hondius cluster under standard hantavirus protocol: rodent reservoir, no person-to-person chain, WHO global risk assessment low. The bulletin was rendered outdated when CIDRAP reported on 7 May that a Swiss passenger had tested positive for Andes virus, the only hantavirus with documented person-to-person transmission. The Andes confirmation arrived after DON 599 closed; it was not a WHO error of fact but a surveillance-lag problem in which the institutional bulletin captured reality at one moment in time and the virus moved faster than the publication cycle. The DON also established the 1 April departure date from Ushuaia, which Africa CDC's 6 May statement contradicted with a 20 March date, creating an unresolved departure-date discrepancy with direct bearing on exposure-site analysis.