The essentials

Hantavirus is caught from wild rodents, usually by breathing dust from their droppings or urine. It starts like the flu, 1 to 8 weeks after exposure. In the Americas it can then attack the lungs within days; in Europe and Asia it mainly affects the kidneys. Low platelets, a high hematocrit and protein in the urine are typical clues on routine tests, and antibody tests confirm it. Trouble breathing after rodent exposure is an emergency.

What is hantavirus, at a glance?

  • Cause: a group of viruses carried by rodents, which shed them in urine, droppings and saliva[1].
  • Two diseases: hantavirus pulmonary syndrome (HPS, also called cardiopulmonary syndrome) in North and South America, and hemorrhagic fever with renal syndrome (HFRS) in Europe and Asia[1][2].
  • How serious: about 38% of people with HPS who develop breathing symptoms die[2]. HFRS ranges from under 1% (Puumala virus) to 15% (Hantaan virus)[4].
  • How rare: the United States counted 890 confirmed cases from 1993 to 2023[5]; Europe sees several thousand cases a year[1].
  • Contagious? No, except the Andes virus of South America, which can pass between people in close, prolonged contact[1].
  • Key tests: complete blood count, kidney tests and urinalysis for warning signs, then IgM and IgG antibodies or PCR to confirm[11].

What are the first symptoms of hantavirus?

Symptoms usually begin 1 to 8 weeks after contact with infected rodents[1]; for HFRS, most often 1 to 2 weeks[4]. Both forms start with a flu-like phase.

  • Common Fatigue, fever and muscle aches, especially in the thighs, hips, back and sometimes shoulders[2].
  • Common In about half of patients: headache, dizziness, chills, nausea, vomiting, diarrhea or stomach pain[2].
  • Possible In HFRS: sudden intense headache, back and belly pain, blurred vision, a flushed face, red eyes or a rash[4].

Lung form (Americas). Four to 10 days after the first phase, a cough, shortness of breath and chest tightness appear as the lungs fill with fluid[2]. Low blood pressure and low oxygen can follow within 24 hours of the first medical visit[3].

Kidney form (Europe, Asia). Classic HFRS goes through five phases: fever, low blood pressure, low urine output, high urine output, then recovery[9]. In nephropathia epidemica, the mild form caused by Puumala virus, flank pain and short-sightedness are typical, kidney function drops around day 7, and fewer than 10% of patients need dialysis[7].

When should I go to the ER for hantavirus symptoms?

When to see a doctor

  • Emergency: call 911 for fever with shortness of breath, a fast-worsening cough, chest tightness, fainting, or very little urine, after any contact with rodents or a dusty closed space[2][3]. The lung form can turn life-threatening within a day.
  • Within 24 hours for fever and strong muscle aches in the 8 weeks after cleaning a shed, cabin or barn, or after seeing mouse droppings at home. Tell the doctor about the rodent exposure[2].
  • At your next appointment if you had an exposure but feel well, to discuss which symptoms to watch for, or if you are recovering and need kidney tests rechecked.

How do you get hantavirus, and who is at risk?

Most people breathe in the virus when dried rodent urine or droppings are stirred up as dust. A bite or scratch is rare[2]. In the United States, the deer mouse carries the most common virus; Seoul virus, carried by rats worldwide, also causes HFRS in the US, including from pet rats[2][4].

  • Common Cleaning closed spaces with rodent signs: sheds, cabins, garages, barns, attics[1].
  • Possible Rural work and outdoor stays in rodent areas: farming, forestry, camping[2].
  • Rare Person to person: only with the Andes virus, mostly in households or intimate partners, early in the illness[1]. A 2026 cluster on the cruise ship MV Hondius, which left Ushuaia, Argentina, counted 7 cases and 3 deaths by May 4; WHO judged the risk to the public low[6].

Which blood and urine tests show hantavirus, and how do I read them?

Doctors usually order a blood count with differential, a metabolic panel for kidney and liver function, a urinalysis and a chest X-ray[11]. Two problems drive the disease: leaky blood vessels and a sharp fall in platelets[10]. Here is a fictitious report.

Fictitious example of a lab report (United States format)
TestResultReference rangeFlag
Platelet count64 x10³/µL150-400 x10³/µLL
Hematocrit53%37-48% (male)H
White blood cell count14.2 x10³/µL4.5-11.0 x10³/µLH
Creatinine1.8 mg/dL0.7-1.3 mg/dL (male)H
Urine protein (dipstick)2+ (100 mg/dL)NegativeA
Hantavirus IgM antibodies (ELISA)PositiveNegative
  1. Platelets, flagged L: below 150,000 per microliter is thrombocytopenia[12]. In a Brazilian series of the lung form, 92% of patients were below this level[9].
  2. Hematocrit, flagged H: plasma leaking out of the vessels concentrates the blood. A hematocrit above 45% was seen in 70% of the same patients[9].
  3. White cells, flagged H: raised in 67% of them[9]; a moderate rise also occurs in the European form[7].
  4. Creatinine and urine protein: the hallmark of the kidney form, with transient protein in the urine, microscopic blood and a moderate creatinine rise[7]. In the lung form, kidney function is sometimes mildly affected[3].
  5. IgM positive: points to a recent infection[3]. Ranges shown come from MedlinePlus[12][13]; your laboratory's range applies.

Low platelets, a high hematocrit and a rising creatinine on the same report? BloodSense reads every line of your complete report, shows which results fit together and helps you prepare your questions for your doctor.

Get my full report explained

This pattern is a clue, not a diagnosis. WHO lists influenza, COVID-19, viral pneumonia, leptospirosis, dengue fever and sepsis among the look-alikes[1]. Read more on the platelet count, the hematocrit test, white blood cells, blood creatinine and protein in urine. A random urine sample normally holds 0 to 14 mg/dL of protein[14].

How is hantavirus confirmed: IgM, IgG and PCR?

  • IgM antibodies: the standard test for a recent infection, usually by ELISA[3]. They are often present when symptoms start and can stay up to 2 years[7].
  • IgG antibodies: IgM and IgG together, or a clear rise of IgG between two samples taken at least 14 days apart, confirm an acute infection[7][8].
  • RT-PCR: finds the virus's genetic material in blood, mainly in the first week. The virus circulates only briefly, so a negative PCR does not rule out the disease[7][8].
  • Which virus: European laboratories must test for both Puumala and Dobrava; a positive rapid test should be confirmed[7].

Results can take time, so treatment of a suspected case is not delayed: people with the lung form need emergency care at once[3].

Which tests are repeated during recovery?

In hospital, the blood count, creatinine, electrolytes, urine output and oxygen level are followed closely; in the lung form, a blood lactate above 4.0 mmol/L is one sign of a severe course[3]. See our guide to oxygen saturation and blood gases. Platelets usually recover first. Full recovery can take weeks to months[4][11], so kidney tests and urine protein may be rechecked after discharge.

How is hantavirus treated?

No doses are given here: your medical team decides.

  • No specific antiviral: care is supportive, for the lungs, heart and kidneys[1]. Early access to intensive care improves outcomes, especially in the lung form[1].
  • Lung form: oxygen, careful fluids, a breathing machine if needed, and broad-spectrum antibiotics while waiting for the diagnosis. ECMO, a machine that oxygenates the blood, has an 80% survival rate when started at the first sign of decline. Ribavirin did not work for HPS[3].
  • Kidney form: fluids, electrolytes and blood pressure support; dialysis if needed. Given early, intravenous ribavirin can reduce illness and death from HFRS[4].
  • Andes virus: the patient is isolated and close contacts are monitored; in the 2026 cluster, WHO asked passengers to watch for symptoms for 45 days[6].

How can I prevent hantavirus when cleaning a shed or cabin?

There is no licensed vaccine[1]. Prevention means keeping rodents out and not breathing their dust.

  • Seal holes and gaps in your home and garage, set traps and store food in closed containers[2].
  • Air out a closed shed or cabin before entering. Do not dry-sweep or vacuum droppings: wet them first with a disinfectant, then wipe[1].
  • Wear gloves and wash your hands afterwards[1].
  • Note the date of the cleaning and watch for fever for 8 weeks[1].

Questions to ask your doctor

  1. Could my fever be hantavirus, given my contact with rodents?
  2. Do my platelets, hematocrit and creatinine fit this infection?
  3. Which antibody test was done, and should it be repeated?
  4. Which breathing or urine changes mean I must go to the emergency room?
  5. When should my kidney tests and urine protein be rechecked?
  6. How should I clean the place where I was exposed?

Frequently asked questions

Is hantavirus contagious?

The hantaviruses of North America, Europe and Asia do not spread between people. Only the Andes virus, found mainly in Argentina and Chile, has caused limited person-to-person spread[1].

Can you survive hantavirus?

Yes. Most people with the European kidney form recover; with Puumala virus, fewer than 1% die[4]. The lung form is more dangerous, and early intensive care improves survival[1].

Can pet rats carry hantavirus?

Yes, pet rats can carry Seoul virus. CDC does not recommend pet rodents in homes with children aged 5 or younger, pregnant women or people with weak immunity[4].

Was the 2026 cruise ship outbreak a risk for the public?

WHO assessed the risk to the global population as low and advised against travel or trade restrictions[6].

  1. World Health Organization. Hantavirus. Fact sheet, May 6, 2026. who.int (accessed November 6, 2026)
  2. Centers for Disease Control and Prevention. About hantavirus. May 13, 2024. cdc.gov (accessed November 6, 2026)
  3. Centers for Disease Control and Prevention. Clinical overview of hantavirus pulmonary syndrome. cdc.gov (accessed November 6, 2026)
  4. Centers for Disease Control and Prevention. Clinical overview of hemorrhagic fever with renal syndrome. cdc.gov (accessed November 6, 2026)
  5. Centers for Disease Control and Prevention. Reported cases of hantavirus disease. April 23, 2026. cdc.gov (accessed November 6, 2026)
  6. World Health Organization. Disease Outbreak News: Hantavirus cluster linked to cruise ship travel, multi-country. May 4, 2026. who.int (accessed November 6, 2026)
  7. Robert Koch Institute (Germany). RKI-Ratgeber Hantavirus-Erkrankung. November 13, 2020. rki.de (accessed November 6, 2026)
  8. National Institute for Public Health and the Environment (RIVM, Netherlands). LCI-richtlijn Orthohantavirusinfectie. January 9, 2026, updated May 15, 2026. lci.rivm.nl (accessed November 6, 2026)
  9. Jonsson CB, Figueiredo LT, Vapalahti O. A global perspective on hantavirus ecology, epidemiology, and disease. Clin Microbiol Rev. 2010;23(2):412-441. doi:10.1128/CMR.00062-09 (accessed November 6, 2026)
  10. Avšič-Županc T, Saksida A, Korva M. Hantavirus infections. Clin Microbiol Infect. 2019;21S:e6-e16. doi:10.1111/1469-0691.12291 (accessed November 6, 2026)
  11. MedlinePlus Medical Encyclopedia. Hantavirus. Reviewed May 25, 2026. US National Library of Medicine. medlineplus.gov (accessed November 6, 2026)
  12. MedlinePlus Medical Encyclopedia. Platelet count. Reviewed February 3, 2025. US National Library of Medicine. medlineplus.gov (accessed November 6, 2026)
  13. MedlinePlus Medical Encyclopedia. Creatinine blood test. Reviewed July 13, 2025. US National Library of Medicine. medlineplus.gov (accessed November 6, 2026)
  14. MedlinePlus Medical Encyclopedia. Protein urine test. Reviewed July 13, 2025. US National Library of Medicine. medlineplus.gov (accessed November 6, 2026)

This page is general information. It does not replace the advice of a doctor, who interprets your results with your symptoms, exposure to rodents and examination.