South Africa Detects Human-Transmissible Andes Hantavirus Linked to Cruise Ship Outbreak

South Africa confirmed the Andes strain of hantavirus, which can spread between humans, in two passengers from the MV Hondius. The outbreak has caused three deaths, with more cases under investigation, as the World Health Organization conducts contact tracing and monitors risks, which remain low overall.

South Africa has confirmed that the Andes strain of hantavirus—one of the rare variants capable of spreading from person to person—has been identified in two individuals who disembarked from the outbreak-affected cruise ship MV Hondius. The discovery was disclosed in a presentation to parliament by health authorities, raising concern because most hantavirus strains are typically transmitted only through contact with infected rodents rather than between humans.
The Hondius, operated by Oceanwide Expeditions, is currently being held offshore near Cabo Verde as authorities assess the outbreak and determine how to safely manage passengers and crew. The vessel had departed from Argentina roughly three weeks earlier on a high-end expedition cruise, carrying about 150 passengers, many of them from Europe and North America. The journey included visits to Antarctica and some of the most remote islands in the South Atlantic before heading toward West Africa.
The outbreak has so far been linked to seven cases of hantavirus infection. According to health officials and the World Health Organization (WHO), three of those infected have died, one person is in critical condition, and three others are experiencing mild symptoms. Among the fatalities is a Dutch woman whose case has become central to international contact tracing efforts.
The woman had disembarked from the ship on Saint Helena on April 24 after developing gastrointestinal symptoms. She then boarded a flight to Johannesburg, during which her condition rapidly deteriorated. She died two days later, on April 26. Her husband, who had also been on the ship, died earlier during the voyage, making them part of the confirmed fatalities linked to the outbreak.
In response, the WHO has initiated contact tracing for all passengers who were on the Saint Helena–Johannesburg flight, seeking to identify individuals who may have been exposed. This step is considered especially important given the involvement of the Andes strain, which has documented cases of human-to-human transmission, unlike most other hantavirus variants.
South African authorities have also confirmed that one patient currently receiving treatment in Johannesburg tested positive for hantavirus, further linking the country to the outbreak response. Health officials are closely monitoring all known contacts and reinforcing surveillance measures to prevent further spread.
Experts note that hantavirus is generally a rodent-borne disease, transmitted when people inhale particles contaminated by rodent urine, droppings, or saliva. However, the Andes strain has been associated with limited human transmission in past outbreaks, particularly in close-contact settings. This characteristic has heightened vigilance among global health agencies.
The illness often begins with non-specific symptoms such as fever, fatigue, and muscle aches, which can make early detection difficult. In more severe cases, it can rapidly progress to hantavirus pulmonary syndrome, a life-threatening condition that causes fluid buildup in the lungs and can lead to respiratory failure. According to the Centers for Disease Control and Prevention (CDC), the fatality rate for severe forms of the disease can be as high as 40%.
Despite the seriousness of the outbreak, the WHO has reiterated that the overall risk to the broader public remains low. Authorities in Cabo Verde have taken precautionary measures by keeping the ship offshore while health screenings and response planning continue. Meanwhile, Oceanwide Expeditions has said it is working with international health bodies to manage the situation and arrange safe disembarkation for passengers once conditions allow.
The incident has drawn global attention due to the combination of factors involved: a rare strain of the virus, international travel, and the confined environment of a cruise ship. Investigations are ongoing to determine how the virus was introduced on board and whether additional cases may emerge among passengers or crew as monitoring continues.