Three individuals have died following an outbreak of hantavirus on a cruise ship currently travelling from Argentina to Cape Verde. The World Health Organization (WHO) has confirmed that a total of seven cases have been identified on the vessel: two confirmed by laboratory testing and five others categorised as suspected. This cluster of cases has led to a comprehensive investigation by the WHO, which includes examining the unusual possibility of human-to-human transmission.
Hantaviruses are a family of viruses carried by rodents that can cause severe, sometimes fatal, diseases in humans. The most common route of transmission to humans is through contact with infected rodent droppings, urine, or saliva, often when these particles become airborne. Less commonly, transmission can occur through a bite from an infected rodent. The symptoms of hantavirus infection can vary depending on the specific strain, but often begin with flu-like symptoms such as fever, muscle aches, headaches, and gastrointestinal issues, progressing in some cases to severe respiratory or kidney problems.
Professor Jonathan Ball from the Liverpool School of Tropical Medicine, in conversation with Madeleine Finlay on a recent podcast, explained the typical transmission pathways and the severity of hantavirus infections. He highlighted that while human-to-human transmission is extremely rare for most hantavirus strains, it has been documented for one particular type, Andes virus, which is found in South America. This specific characteristic makes the investigation into the cruise ship outbreak particularly pertinent given the vessel's origin.
The current investigation will focus on identifying the specific hantavirus strain involved and thoroughly mapping the epidemiological links between the cases. Understanding whether the virus on board is one of the strains known for rare human-to-human spread, such as the Andes virus, will be crucial. This information will inform public health responses and help to mitigate further spread, both on the ship and potentially once passengers disembark.
For the UK, while hantavirus is not endemic in the same way as in parts of the Americas or Asia, cases can occasionally be reported, typically linked to travel or exposure to rodents in specific environments. Public Health England (now UK Health Security Agency) has previously issued guidance on rodent control to prevent such infections. The ongoing investigation by the WHO underscores the importance of global health surveillance and rapid response to emerging infectious disease threats, regardless of their geographical origin.