The first genome analysis results of the hantavirus that caused a cluster infection on the cruise ship "MV Hondius," which departed from Argentina, have been released. Analyses so far indicate no major differences from the existing South American Andes virus lineage.
The National Reference Center for Emerging Viral Infections at the University Hospitals of Geneva in Switzerland on the 8th (local time) released for the first time the complete genome sequence of the virus from this infection case via the expert forum virological.org.
The cluster occurred on the polar expedition cruise MV Hondius, which departed from Argentina and is crossing the Atlantic. Of the 147 passengers and crew on board, as of the 8th there were eight suspected cases and six confirmed cases, three of whom died.
Hantaviruses are typically transmitted through excreta or saliva of rodents. In many cases, fine particles formed as excreta dry become airborne and are inhaled, leading to infection. However, the World Health Organization (WHO) said no rats were found on the cruise ship. Accordingly, the WHO suspects the possibility of person-to-person transmission, but it has not yet been determined.
Damien Tully of the London School of Hygiene & Tropical Medicine (LSHTM)–Uganda Virus Research Institute joint research unit said via the U.K. Science Media Centre (SMC), "The currently released genome is broadly similar to hantaviruses that have spilled over from established natural reservoirs to humans," adding, "There is no indication that a dramatically altered new virus has emerged."
Tully said, "It is closest to the Andes virus lineage identified during the 2018–2019 outbreak in Argentina," and "So far, there is no evidence of genome reassortment or abnormal evolution." Reassortment is a phenomenon in which different viruses exchange parts of their genetic material to create new variants.
Piet Maes, a virologist and professor at the Rega Institute of KU Leuven in Belgium, also said, "This virus appears to be a typical Andes virus lineage that has been circulating in rodent reservoirs in Chile and Argentina," adding, "No unusual mutations beyond the expected range have been observed."
However, experts stressed that caution is needed in interpreting the findings, as the currently released data are based on the genome from a single patient.
Tully said, "At present we cannot determine whether there were multiple spillovers from animals to humans, or whether person-to-person transmission continued after a single infection," adding, "Genome analyses of additional patients and animal reservoirs are needed."
He added, "If the patients' viral genomes are nearly identical, that could support recent person-to-person transmission, but if there are large genetic differences, each may be an independent animal infection event."
Meanwhile, the MV Hondius is scheduled to arrive in Spain's Canary Islands on the 10th. Local authorities plan to disembark passengers, then quarantine and test them before sending them to their home countries. However, amid continued opposition from residents, there is talk that only passengers may disembark while the vessel does not enter port.
These expert comments were provided through the Science Media Center Korea (SMCK). SMCK is a nonprofit that connects the scientific community and the media, providing expert analyses and verified information on major science issues at home and abroad.