JOHANNESBURG – A coordinated international public health operation is underway following a hantavirus outbreak aboard a South Atlantic cruise ship that has resulted in multiple deaths and an urgent contact tracing effort for passengers of a commercial flight to South Africa.
The crisis escalated into an international alert after a female passenger, who had been aboard the vessel, traveled on Airlink flight 4Z132 from St. Helena Island to Johannesburg on April 25, 2026. The passenger’s condition deteriorated rapidly during the flight; she died shortly after arrival at a Johannesburg emergency department on April 26. Subsequent PCR testing confirmed she was infected with hantavirus.
The incident highlights the precarious nature of zoonotic disease transmission within the global travel network, specifically involving the Andes virus strain. While hantaviruses are typically contracted from rodents, the Andes virus-endemic to South America-is one of the few strains documented to facilitate limited human-to-human transmission, a factor that has heightened the urgency of the current contact tracing mission.
Flight 4Z132 and Contact Tracing
The World Health Organization (WHO) and Airlink are currently advising 82 passengers and six crew members from flight 4Z132 to contact South African health authorities immediately. South Africa’s National Department of Health, operating under the International Health Regulations framework administered by the World Health Organization, has activated protocols for managing high-consequence infectious disease events linked to international travel.
Airlink reported that it was unaware of the passenger’s illness during the transit. To facilitate the Department of Health’s investigation, the airline has provided the complete flight manifest, including seating allocations and passenger contact details, which are being cross-checked with immigration and port health records at Johannesburg’s main international gateway.
Addressing concerns over cabin transmission, the airline emphasized that its fleet is equipped with hospital-grade High Efficiency Particulate (HEPA) filters, which are engineered to repeatedly scrub cabin air of airborne contaminants. Public health officials note, however, that close contact in confined spaces still requires careful assessment of seat proximity and duration of exposure.
Authorities are prioritizing passengers seated in the same row as the infected traveler and in adjacent rows, as well as crew members who provided direct in-flight assistance. Contact tracers are conducting symptom checks, advising immediate medical evaluation for anyone with fever or respiratory complaints, and recommending isolation where clinically indicated.
Chronology of the Cruise Outbreak
The outbreak originated on a vessel that departed from Ushuaia, Argentina, on April 1, 2026. Ushuaia, the southernmost city in the world, serves as a primary gateway to Antarctica and is located within regions where hantavirus-carrying rodents are known to exist.
The ship followed a remote South Atlantic itinerary with stops in Antarctica, South Georgia, and St. Helena. The cluster of severe respiratory illnesses was officially reported to the WHO on May 2, though symptoms had appeared weeks earlier, triggering retrospective reviews of onboard medical logs and port health declarations.
The timeline of the outbreak includes:
- April 6: The first victim, an adult male, developed symptoms.
- April 11: The first death occurred aboard the ship.
- April 25: A female passenger departed St. Helena for Johannesburg.
- April 26: The female passenger died upon arrival in Johannesburg.
- April 27: A male passenger was medically evacuated from Ascension Island to South Africa; he remains in critical condition in an intensive care unit.
- May 2: A fourth passenger, an adult female, died after presenting with pneumonia.
The vessel is currently moored off the coast of Cabo Verde. Of the 147 passengers and crew, the WHO has identified seven individuals with the virus, consisting of two laboratory-confirmed cases and five suspected cases. Three suspected cases currently remain in quarantine on board, under the supervision of international medical teams and Cabo Verdean port health authorities.
Health officials are also working with cruise operators and maritime regulators to review sanitation protocols, rodent-control measures, and pre-embarkation screening on similar expedition routes, amid concern that the combination of remote landings and shared onboard living spaces can accelerate outbreaks of rare pathogens.
Clinical Presentation and Viral Pathogenesis
Medical reports indicate the victims suffered from a rapid progression of symptoms, beginning with fever and gastrointestinal distress and advancing quickly to pneumonia and acute respiratory distress syndrome (ARDS). In several cases, deterioration reportedly occurred over a matter of hours once respiratory symptoms became pronounced.
Hantavirus Pulmonary Syndrome (HPS) typically occurs when the virus causes capillary leak in the lungs, leading to pulmonary edema and severe breathing difficulties that often require intensive care and ventilatory support. While the primary vector is the urine, feces, or saliva of infected rodents, the WHO is investigating the specific nature of this cluster’s exposure, including the possibility of environmental contamination at shore excursions and confined-space exposure on board.
Both the first victim and the passenger on the Airlink flight had traveled through South America, including Argentina, prior to boarding the cruise, suggesting a possible primary exposure in the Southern Cone. Andes virus, the suspected strain in this outbreak, has been associated with person-to-person spread in past clusters, particularly in close household or caregiving settings, raising questions about how effectively standard shipboard isolation measures can interrupt transmission.
Public health experts stress that hantavirus infections remain rare globally, but their severity and rapid course demand swift recognition and hospital-level care. The South African authorities have issued clinical alerts to emergency departments and intensive care units, advising them to inquire about recent travel to South America, St. Helena, or the affected cruise and to use appropriate infection prevention measures.
The WHO urges passengers who took Airlink flight 4Z132 from St. Helena to Johannesburg on April 25 to contact health authorities over hantavirus concerns.
The response is currently being managed through a framework of medical evacuations, strict case isolation, and in-depth laboratory investigations to determine the exact strain of the virus and the extent of human-to-human transmission. Laboratories in South Africa and international reference centers are conducting genomic sequencing to confirm the link to the Andes virus strain and to look for any mutations that might influence transmissibility or disease severity.
At a policy level, the incident is already testing coordination between aviation regulators, port health authorities, and infectious disease agencies, as governments weigh whether to adjust screening for travelers arriving from affected itineraries. Cruise operators have begun notifying future passengers of potential itinerary changes and enhanced health protocols.
The ship remains stationary off Cabo Verde pending further health clearances and the completion of the WHO investigation. Officials have signaled that the vessel will not be permitted to resume normal operations until health authorities are satisfied that all active cases have been identified, immediate contacts monitored, and the risk of further international spread significantly reduced.