Hantavirus infections linked to cruise ship

Timeline and international response

The first notification was received by WHO on 2 May from the United Kingdom, which reported the incident under the International Health Regulations. The reason was a passenger with severe respiratory symptoms on board a ship travelling from Argentina to Cabo Verde. At that time, 149 people from 23 countries were on board.

WHO has since published a more detailed timeline of the cluster. The first patient linked to the ship developed symptoms on 6 April and died on 11 April. His spouse later became ill, subsequently disembarked, and died on 26 April. A third passenger on the ship developed symptoms on 24 April and remains in intensive care in South Africa. Testing in South Africa confirmed hantavirus infection and subsequently identified the virus as Andes virus, a subtype. One additional passenger died on 2 May, and four have been admitted to hospitals in Europe, in the Netherlands and Switzerland. When the WHO published its update on 7 May, no passengers or crew members who were still on board were showing symptoms.

Spain agreed to allow the ship to dock in the Canary Islands after Cabo Verde rejected a request to dock there due to public health concerns. Tedros Adhanom Ghebreyesus, Director-General of WHO, thanked Spain for its response and said: “The risk to the population of the Canary Islands is in fact low.”

What is hantavirus?

Hantaviruses are a group of viruses carried by rodents. People usually become infected after close contact with infected rodents or their urine, feces, or saliva. Infection can occur when people inhale dust or particles containing infectious material, especially in enclosed or poorly ventilated spaces. Infection can also occur through direct contact with infectious material or, more rarely, through rodent bites.

Very few hantaviruses spread between people. Andes virus is an important exception, as limited person-to-person transmission has been confirmed, usually after close and prolonged contact, for example, among household members, partners, or during patient care.

WHO has emphasized that this cluster is unlike COVID-19 or influenza and that this is not the beginning of a pandemic. WHO notes that hantaviruses have long existed, are well known, and do not spread as easily as coronaviruses or influenza viruses.

Hantaviruses found in North, Central, and South America are known to cause hantavirus cardiopulmonary syndrome. The Andes virus belongs to this family and is the only one known to cause person-to-person transmission in cases of very close contact.

Hantaviruses found in Europe and Asia are known to cause hemorrhagic fever with renal syndrome. Person-to-person transmission is not known to be associated with those hantavirus subtypes.

Public health and infection control

Follow-up by authorities continues in several countries, as some passengers had already disembarked before the infection was confirmed. They are considered exposed, and countries are contacting their nationals and taking measures regarding guidance on symptom monitoring, testing, quarantine, and isolation as appropriate, while contact tracing continues. These measures are precautionary and do not change the assessment that the risk to the general public is low.

A WHO expert, Dutch physicians, and an ECDC expert boarded the ship in Cabo Verde, conducted health checks and a risk assessment, and reviewed infection-control measures and supplies for the voyage to Tenerife. Passengers who remained on board were asked to stay in their cabins while disinfection was carried out. If anyone developed symptoms, that person would be isolated immediately.

WHO has also provided diagnostic tests to laboratories in five countries and is working on guidance for the safe disembarkation of passengers and their return home. ECDC is also cooperating with health authorities in individual countries and supporting guidance and testing.

Monitoring continues because the incubation period for the Andes virus can be up to six weeks, meaning the time from infection until symptoms appear.

Symptoms of hantavirus infection

Symptoms of hantavirus infection may begin with fever, headache, bone and muscle pain, and gastrointestinal symptoms may follow, such as nausea, vomiting, abdominal pain, or diarrhea. Severe illness caused by hantaviruses in the Americas can develop rapidly into cough, shortness of breath, fluid accumulation in the lungs, and shock. Hantavirus cardiopulmonary syndrome can be severe and, in some cases, fatal.

Anyone who has been identified as a passenger, crew member, or close contact of MV Hondius must follow the advice of the authorities in their country and seek medical care immediately if symptoms develop.

There is no specific antiviral treatment or vaccine for hantavirus infection. Treatment consists of supportive care, monitoring, and management of complications affecting the respiratory system, heart, and kidneys. Early medical care, including intensive care when needed, improves outcomes.

False information and rumors

WHO has responded to false and misleading information circulating on social media. WHO has stated that there are no signs of the beginning of a pandemic. Well-known infection control measures are being used, including contact tracing, isolation, monitoring, and general infection control measures such as cleaning, which can break chains of transmission and prevent further spread.

A previous limited cluster of Andes virus infections in Argentina from November 2018 to February 2019 was linked to close contact in a close setting. WHO has also cited that experience to explain why large-scale spread is unlikely when appropriate infection control measures are in place.

What does this mean for the general public?

This is a serious cluster of infections that requires coordination and international cooperation, as well as appropriate infection control measures for the care of those who have become ill and for monitoring those who were on board during the incubation period. Passengers, crew, and close contacts linked to MV Hondius, therefore, need to follow guidance, but the general public does not need to be concerned.

The Chief Epidemiologist