#19,138
While we await further details on the (suspected) Hantavirus outbreak aboard a cruise ship in the Atlantic (see yesterday's blog), we have the following brief statement by the World Health Organization.
As of this posting, no DON has been published on this event, and that may not come for several days. Sequencing of the virus will not only tell us more about its origin (is it the Andes strain?), it could also help define transmission dynamics aboard ship.
While the WHO's messaging remains low-key, they are obviously taking this outbreak seriously, as they have notified their NFPs (National Focal Points) according to the IHR regulations.
The BBC this morning is reporting that local authorities will not permit passengers to leave the ship in Cape Verde in order `to protect the public'. It is not clear where or when the passengers will be allowed to disembark.
Although human-to-human spread of the Andes virus has been documented (see EID Journal), the Andes Virus is not believed to transmit as easily as COVID, influenza, and many other respiratory viruses.
Transmission likely requires close, prolonged exposure to respiratory droplets or other bodily fluids.
But there is still much we don't know about this virus, including its ability to spread asymptomatically.
Studies have suggested (see Serological Evidence of Hantavirus Infection in Apparently Healthy People from Rural and Slum Communities in Southern Chile) that at least some infections are mild or asymptomatic.
A more recent 2025 study (see Virological characterization of a new isolated strain of Andes virus . . .), published in PloS NTD reported:
In this work, we described the isolation of the strain responsible for the largest ANDV PTP transmission outbreak, which occurred in the small town of Epuyén and began on November 2, 2018. This strain, ARG-Epuyén, exhibited a high capacity for PTP transmission, necessitating the implementation of quarantine measures to curtail further spread [8].
The median reproductive number (the mean number of secondary cases caused by an infected person) was 2.12 before control measures were implemented and subsequently dropped to below 1.0 by late January.
Early intervention allowed for the collection of samples leading to the isolation of this new ANDV strain from an asymptomatic case. An early passage of this strain was sequenced, revealing only one amino acid difference from the virus recovered from the patient. Like the Andes/ARG strain, this strain was able to grow in a new host without needing adaptation [26].
All reasons why public health officials will want to proceed cautiously as they work to contain this outbreak.
