Guide

What is hantavirus?

Hantavirus is a name for a family of viruses — not one single virus — and that is why the term can be confusing in headlines. Different hantaviruses circulate in different rodents, in different parts of the world, and the illness they cause in humans can look very different.

There are two broad clinical syndromes:

• Hantavirus Pulmonary Syndrome (HPS) — caused mainly by New World hantaviruses (e.g. Sin Nombre virus in North America, Andes virus in South America). It primarily attacks the lungs and carries a high case fatality rate (historically 30–40%).
• Hemorrhagic Fever with Renal Syndrome (HFRS) — caused mainly by Old World hantaviruses (e.g. Hantaan, Seoul, Puumala). It primarily affects the kidneys, with a fatality rate that varies widely by virus, from less than 1% (Puumala) to about 10% (Hantaan).

TL;DR

• Most infections are rodent-borne and linked to exposure to contaminated dust.
• The same word (“hantavirus”) can refer to illnesses with very different severity.
• Person-to-person spread is uncommon, with a notable exception: Andes virus (ANDV) in parts of South America.

How people get infected (most commonly)

The dominant route is inhaling aerosolized particles from the urine, droppings, or saliva of infected rodents — often when dust is disturbed in enclosed spaces. It is less commonly acquired through bites or direct contact.

Why public advisories can be vague at first

Until the virus species responsible for a cluster is confirmed, agencies often write “hantavirus infection” without committing to HPS or HFRS. That is not hedging for effect — it reflects real diagnostic uncertainty early in an investigation.

What to do

If you think you had meaningful rodent exposure and develop fever and severe muscle aches, seek medical advice promptly and share the exposure history. For household cleaning guidance, see the prevention page.

Symptoms and timeline

Symptoms typically begin 1 to 8 weeks after exposure, with most cases appearing within 2–4 weeks. Both syndromes start with a non-specific febrile phase that can be mistaken for influenza.

Early phase (days 1–5):

• Fever, chills, body aches
• Severe muscle aches in the thighs, hips, back, shoulders
• Headache, dizziness
• Abdominal symptoms: nausea, vomiting, diarrhea

Late phase (days 4–10), HPS:

• Cough
• Shortness of breath that can progress rapidly to pulmonary edema
• A feeling of “tightness” or a band around the chest

Late phase, HFRS:

• Low blood pressure / shock
• Reduced urine output, kidney failure
• Petechiae and other bleeding signs in severe cases

If you developed symptoms after potential exposure to rodent droppings or contaminated dust — and especially if you were a passenger or crew member on the ship listed on this site — seek medical care promptly and tell the clinician about the exposure.

HPS vs HFRS

You’ll often see “hantavirus” used as if it describes one disease. In practice, public health reporting usually falls into two major clinical patterns. Understanding them helps you interpret risk and headlines.

TL;DR

• HPS (Hantavirus Pulmonary Syndrome) mainly affects the lungs and is reported mostly in the Americas.
• HFRS (Hemorrhagic Fever with Renal Syndrome) mainly affects the kidneys and is reported mostly in Europe and Asia.
• Early symptoms can look similar (fever, aches), which is why early reporting may be non-specific.

What is HPS?

HPS is associated with “New World” hantaviruses. It often begins like influenza — fever, fatigue, and severe muscle aches — and can then progress rapidly to shortness of breath as fluid builds up in the lungs.

What is HFRS?

HFRS is associated with “Old World” hantaviruses. It can involve low blood pressure and bleeding signs in severe cases, but a defining feature is kidney involvement, including reduced urine output and, sometimes, kidney failure.

Why the names can be misleading

Not every patient reads the textbook. Authorities may use broader terms early on (“hantavirus infection”) until laboratory confirmation clarifies which virus is involved and what syndrome is most likely.

What to do

If you’ve had plausible exposure and develop fever plus worsening respiratory symptoms or signs of severe illness, seek urgent medical care and mention the exposure. Early supportive care can be life-saving.

How hantavirus spreads

Hantaviruses are rodent-borne. The dominant route of human infection is inhalation of aerosolized particles of urine, droppings, or saliva from infected rodents — often when these contaminate dust that is then disturbed by sweeping, vacuuming, or moving objects in an enclosed space.

Other documented but less common routes:

• Direct contact with infected rodents (e.g. bites)
• Contact with contaminated material followed by touching the eyes, nose, or mouth
• Eating food contaminated by rodent excreta

Person-to-person transmission is rare for most hantaviruses. The notable exception is Andes virus (ANDV) in South America, where limited human-to-human spread — including in healthcare and household settings, and most strikingly between spouses — has been repeatedly documented.

This matters for the MV Hondius cluster. Reference-laboratory testing has confirmed Andes virus in at least one case, and the working hypothesis is that some passengers were exposed in Argentina before boarding, with onward spread among close contacts on the ship. That makes this one of the relatively rare hantavirus events where person-to-person transmission cannot be dismissed as a possibility — though most cases worldwide remain rodent-acquired.

Why a cruise ship is an unusual setting: ships are tightly enclosed environments with shared ventilation, food storage, and cabins. A rodent infestation that goes unnoticed in a galley or storeroom can produce broad, aerosolized exposure across many passengers and crew.

Treatment and prevention

There is no specific antiviral therapy approved for hantavirus disease and no licensed vaccine in most countries (Hantavax, used in parts of Asia for Hantaan virus, is the main exception). Care is supportive:

• Early ICU admission with respiratory support is the single biggest determinant of survival in HPS.
• For HFRS, careful fluid management and dialysis when needed.
• Ribavirin has shown benefit for some Old World hantaviruses if started early; it is not effective for HPS-causing New World viruses.

For passengers and crew who were on the affected vessel:

1. Monitor your temperature and symptoms for at least 6 weeks after disembarkation.
2. If you develop a fever with severe muscle aches, cough, or shortness of breath, seek medical care immediately and tell the clinician about your travel history.
3. Follow guidance from your country’s public-health authority. Links to the most up-to-date advisories are on the Resources section of the home page.

For the general public: keep rodents out of homes (seal entry points, store food in sealed containers, set traps where appropriate). When cleaning areas with rodent droppings, ventilate the space, wear gloves and a fitted mask, dampen surfaces with disinfectant before wiping, and avoid sweeping or vacuuming dry material.