Hantavirus Outbreak by the Numbers: What We Know So Far

Health authorities around the world are continuing efforts to contain and investigate the hantavirus outbreak linked to the MV Hondius.

The outbreak has triggered international quarantines, contact tracing operations, and emergency health monitoring across several countries.

Here is what the latest numbers reveal about the growing situation.

147 people were aboard the ship

According to the World Health Organization, there were 147 people aboard the MV Hondius during the outbreak.

That total included:

• 88 passengers
• 59 crew members
• Travelers from 23 different nationalities
• 17 American passengers

Health officials are now monitoring passengers and crew members across multiple countries.

At least five confirmed cases identified

WHO officials said there are currently five confirmed hantavirus infections connected to the ship.

Several additional suspected cases remain under investigation.

The outbreak was first officially reported to WHO on May 2.

Three deaths linked to the outbreak

So far, three people connected to the outbreak have died.

The fatalities include:

• A 70-year-old Dutch man who became ill aboard the ship
• His 69-year-old wife, who later died after traveling through Johannesburg
• A German woman who died aboard the vessel on May 2

Health officials confirmed at least one case through molecular testing for hantavirus.

Symptoms began appearing in early April

WHO investigators believe the first passenger developed symptoms on April 6.

The most recent known symptomatic case reportedly began showing signs of illness on April 28.

Multiple countries now involved in contact tracing

Authorities are actively tracing exposed passengers and possible contacts in several countries, including:

• Spain
• Netherlands
• Switzerland
• United Kingdom
• United States
• South Africa

Passengers also disembarked earlier on remote islands including Saint Helena and Tristan da Cunha.

New suspected cases continue emerging

British authorities confirmed a suspected case involving a resident of Tristan da Cunha who had contact with the ship.

Swiss authorities are also monitoring a confirmed patient receiving treatment in Zurich after leaving the vessel.

In the United States, passengers are currently being monitored in states including:

• Georgia
• Arizona
• California
• Texas
• Virginia

So far, no American passengers have reportedly developed symptoms.

The outbreak involves the Andes strain

WHO sequencing confirmed the outbreak involves the Andes strain of hantavirus.

The Andes variant is considered the only known hantavirus strain capable of limited human-to-human transmission.

Experts stress that transmission remains rare and generally requires prolonged close contact.

Hantavirus has a long incubation period

Health officials say hantavirus symptoms can appear anywhere from one to six weeks after exposure.

In some cases, symptoms may emerge as late as eight weeks afterward.

Because of that long incubation period, WHO recommends exposed passengers monitor themselves for symptoms for 45 days.

The virus remains highly dangerous

The Centers for Disease Control and Prevention estimates that roughly 38% of patients who develop hantavirus pulmonary syndrome may die.

There is currently:

• No approved vaccine
• No specific antiviral treatment
• No guaranteed cure

Doctors say early ICU treatment and supportive care significantly improve survival chances.

Human transmission remains uncommon

WHO officials emphasized that the virus does not spread like COVID-19 or influenza.

Transmission involving the Andes strain generally occurs through very close contact, such as between spouses, caregivers, or people sharing confined spaces.

One study from an earlier outbreak in Argentina estimated the virus spread to just over two additional people per infected patient before public health interventions began.

Hantavirus remains rare in the United States

According to CDC data, the United States recorded 890 hantavirus cases between 1993 and 2023.

Most infections occurred in western states.

Globally, researchers estimate there are between 60,000 and 100,000 hantavirus cases each year, with roughly half occurring in China.

Ship remains headed to Tenerife

The MV Hondius departed Cape Verde and is currently sailing toward Tenerife in the Canary Islands.

Spanish officials plan to disinfect the vessel and conduct a full epidemiological investigation once passengers disembark.

Remaining passengers are expected to undergo quarantine and additional testing upon arrival.