A passenger on the MV Hondius cruise ship is hospitalised in Zurich after a confirmed Andes virus infection.
The WHO reported eight cases on board as of May 6, three of which were laboratory-confirmed. Here’s an update on a disease for which there is no treatment or vaccine.
Sudden fever, headaches, muscle pain, then respiratory distress that can lead to death in half of the cases: The Andes virus, a strain of hantavirus that triggered the health alert on board the MV Hondius cruise ship, is one of the most feared infectious agents in South America.
One passenger is currently hospitalised in Zurich after a confirmed infection; three other suspected patients have been evacuated to the Netherlands.
A disease that progresses in two stages
According to the WHO, hantaviruses are zoonotic viruses transmitted to humans primarily through contact with the urine, feces, or saliva of infected rodents, most often through inhalation in enclosed or poorly ventilated spaces. Rodents are the natural reservoir for these viruses and carry them without showing any symptoms.
The first clinical signs – fever, headache, muscle pain, and gastrointestinal problems – appear between one and eight weeks after exposure.
These symptoms are common to many febrile illnesses, making early diagnosis difficult. The WHO highlights their similarity to those of influenza, Covid-19, leptospirosis, or dengue fever.
The disease can then rapidly progress to a severe form. In the Americas, hantaviruses cause hantavirus cardiopulmonary syndrome(HCPS), characterised by cough, shortness of breath, fluid buildup in the lungs, and cardiovascular shock.
The WHO estimates the case fatality rate to be between 20% and 50%, depending on the strain.
Andes virus, the only hantavirus with documented human-to-human transmission
The Andes virus has a characteristic that distinguishes it from all other hantaviruses: it is the only one for which human-to-human transmission has been documented, according to the WHO.
This limited and rare transmission occurs during close and prolonged contact, within the same household or between partners, and appears more likely during the initial phase of the illness, when the viral load ishighest. Its presence is primarily documented in Argentina and Chile.
No treatment, no vaccine
The WHO is clear: to date, there is no approved specific antiviral treatment or vaccine against hantaviruses. Management is exclusively symptomatic, based on clinical monitoring and treatment of respiratory, cardiac, or renal complications.
Early access to intensive care improves the prognosis, particularly in cardiopulmonary forms.
Diagnostic confirmation relies on the detection of specific antibodies (IgM, IgG) and molecular methods such as RT-PCR in the acute phase.
The WHO specifies that non-inactivated biological samples present a biological risk and must be handled under maximum containment conditions.
Eight cases identified, international monitoring underway
As of May 6, eight cases had been identified on board the MV Hondius, three of which were laboratory-confirmed by the National Institute for Communicable Diseases in South Africa and Geneva University Hospitals (HUG), with support from the Pasteur Institute in Dakar and ANLIS in
Argentina.
The WHO Director-General, Tedros Adhanom Ghebreyesus, indicated thatthe organisation is monitoring passengers and crew members, including those who have already disembarked, in accordance with the International Health Regulations.
He said “the overall risk to public health remains low.”
AC/Sf/fss/as/APA