PARIS – France’s world-renowned Pasteur Institute has completed full genomic sequencing of the Andes virus isolated from a French passenger who fell ill after a voyage on the MV Hondius cruise ship, and confirmed that the pathogen matches well-documented strains already circulating in South America. As of the latest update, researchers have uncovered no evidence of new genetic traits that would increase the virus’s transmissibility or make it more lethal to humans.
French Health Minister Stéphanie Rist shared the key findings in a public post on X Friday, emphasizing that the sequenced variant aligns with strains currently tracked by public health systems across South America. “At this stage, no element suggests the emergence” of a more transmissible or dangerous form of the virus, Rist wrote.
Genomic analysis verified that the virus taken from the French patient is an exact match to samples collected from other infected cases on the same vessel, Pasteur Institute officials confirmed. It also bears a very close genetic resemblance to archived Andes virus samples from endemic regions across South America. All virus samples collected from passengers on the MV Hondius are identical to one another, and carry roughly 97% genetic similarity to known Andes strains circulating in South America, including variants found in rodent populations, the natural reservoir for the virus.
Jean-Claude Manuguerra, head of the Pasteur Institute’s Environment and Infectious Risk unit, explained that the 3% genetic divergence seen in the sequenced samples falls within the expected range of natural viral variation. The small differences do not appear to alter the core biological characteristics of the virus that affect how it spreads or harms human hosts, he noted.
The French passenger tested positive for Andes virus following her trip aboard the MV Hondius, and has since received inpatient care at a Paris medical facility. French public health officials previously disclosed that the patient was in serious condition when admitted. Currently, virological investigations remain ongoing, conducted in close collaboration between Pasteur Institute researchers, French national health authorities, and global public health partners. Rist added that the full genomic sequencing data will be shared openly with the international scientific community to support global monitoring and research efforts, noting that the new data will improve understanding of the virus and enable more rigorous ongoing public health surveillance.