ON April 1, a group of people boarded a cruise ship, MV Hondius, at Ushuaia in Argentina on a long-distance expedition marketed as the Atlantic Odyssey. The 33-day cruise was designed to bridge the gap between the Antarctic and the Arctic seasons with stops at exotic island locations like South Georgia, Gough Island and Saint Helena, with Praia (Cape Verde) being the final destination. Instead, it ended up in a nightmare for the passengers as some of them reported severe respiratory illness, and three died due to the illness, which was subsequently identified as a result of hantavirus infection.
The first death occurred on April 11, but the cause remained unidentified. As more people fell sick with similar symptoms, the outbreak was reported to the World Health Organisation (WHO) on May 2. Although the outbreak has been limited to the ship and the virus involved is not new, it has still raised global concern due to the fact that 147 passengers and crew members onboard came from 23 countries, and 34 of them disembarked before the outbreak was identified as hantavirus. This highlights global vulnerabilities in interconnected travel networks.
So far, 11 cases have been reported, including three deaths. All cases are of passengers or crew on the ship. Nine of the 11 have been confirmed as the Andes strain of hantavirus. There have been no deaths after May 2, when the WHO was first informed of the cluster of cases. The health agency took swift action by sending its experts to the ship and coordinating the evacuation of the passengers in accordance with the International Health Regulations (IHR). Under these rules, the nearest port with sufficient medical capacity must be identified to ensure the safety and dignity of those on board. Tenerife (Spain) met that standard, and the Spanish government permitted passengers to disembark on its shore as per IHR and EU regulations.
At present, there is no sign that we are seeing the start of a larger outbreak, according to WHO Director-General Tedros Adhanom Ghebreyesus. This is not another Covid-19, he says. The current public health risk from hantavirus remains low, but the situation could change. Given the long incubation period (about 42 days) of the virus, more cases might emerge in the coming weeks.
Each of the countries to which the passengers have been repatriated is responsible for monitoring their health. Two of the crew members are Indians; they have been evacuated to the Netherlands, where the ship proceeded after disembarking all passengers in Tenerife. Both Indians have been reported to be asymptomatic as of now.
Hantavirus cardiopulmonary syndrome (HPS) is a viral respiratory disease caused by hantaviruses of the genus Orthohantavirus, in which 20 viral species have been identified. At present, there is no specific antiviral treatment for HPS. Human hantavirus infection is primarily acquired through animal-to-human transmission, mostly through contact with the urine, faeces or saliva of infected rodents or by touching contaminated surfaces. However, the Andes strain is capable of spreading among people, as it has happened on the ship. In the present case, it is suspected that an elderly Dutch couple contracted the virus during a bird-watching tour in Ushuaia before they boarded the cruise ship. The couple may have been exposed to infected rodent droppings or urine at a landfill site during their outing.
The hantavirus outbreak has coincided with five years of the deadly second wave of Covid and revived memories of containment measures like quarantine and contact tracing. Since the Covid pandemic, the world has seen several serious outbreaks and public health emergencies of international concern — Mpox, H5N1, Marburg Virus — and local outbreaks of Nipah virus in India and Bangladesh.
The Covid experience has shown that underestimating a virus or its pandemic potential contributes to delayed action. Various studies and models have pointed out that the world remains poorly prepared for pandemics. With environmental changes and greater human mobility, the world is likely to see more outbreaks linked to zoonotic diseases due to pathogens that originate in wildlife.
Deforestation and other human activities in forested areas are affecting the dynamics of rodent populations, and also modifying transmission rates of rodent-borne zoonotic pathogens such as hantavirus, as found in a 2025 study of rodents in North America. Researchers discovered six new rodent species that host hantavirus, and they consider it an emerging disease of pandemic potential with symptoms that resemble severe Covid infection.
The hantavirus outbreak has once again reminded the world that human health is inseparable from animal and environmental health. Factors like deforestation, fragmentation of ecosystems, climate change and even intensive farming are bringing humans and animals into closer contact, creating opportunities for frequent ‘spillover’ for viruses.
Conserving forests and biodiversity is the best natural protection against such opportunistic transfer of zoonotic pathogens. Brazilian scientists have specifically studied the presence of rodent species hosting hantavirus in the Brazilian Atlantic Forest, and have found that forest restoration could significantly reduce the risk of hantavirus transmission to human populations living close to the forests.
Given factors like rich biodiversity, rapid urbanisation, deforestation and the impact of climate change, India is considered a hotspot for emerging infectious diseases, including zoonotic diseases.
In the wake of the Covid pandemic, the government launched the National One Health Mission in 2022, emphasising a unified approach to human and animal health. Subsequently, the National Institute of One Health was conceived to coordinate mission activities. The mission talked about stronger surveillance, early warning systems, research, infrastructure development and the integration of data across human, animal and environmental health.
The progress has been slow, particularly when it comes to research in zoonotic diseases, integrated surveillance of zoonotic and human diseases and risk assessment studies. Research into emerging and re-emerging viruses should be prioritised, along with surveillance on the ground. The hantavirus outbreak is yet another wake-up call.
