Released May 20, 2026

About the Episode

In this installment, Dr. Auwaerter provides a timely overview of hantavirus, focusing on the recent cruise ship outbreak, the distinctions between new and old world strains, early clinical recognition, and the key management principles that can make the difference between survival and death in the most severe cases.

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Episode Summary

Dr. Auwaerter opens by framing the discussion around a recent hantavirus outbreak aboard a cruise ship traveling from southern Argentina through the South Atlantic islands to the Canary Islands—a setting far removed from the rural environments most clinicians associate with the disease. The outbreak highlights several important themes: hantavirus appearing in a non-traditional setting, its early diagnostic challenges, the importance of environmental surveillance in close quarters, and a delayed U.S. public health response relative to the WHO.

Dr. Auwaerter distinguishes between new world and old world hantaviruses. New world strains—such as Sin Nombre and the Andes virus implicated here—primarily affect the lungs, causing hantavirus cardiopulmonary syndrome with fatality rates from 11% to 45%. Old world strains predominantly affect the kidneys, presenting with febrile illness, oliguria, lumbar back pain, and proteinuria, and are generally less lethal. Early new world hantavirus can mimic influenza or COVID-19; key warning signs include thrombocytopenia, rapidly progressive pulmonary edema, and hemoconcentration from capillary leak. The incubation period can extend up to six weeks, requiring clinicians to look well back into a patient’s exposure history. The Andes virus warrants particular concern as the only hantavirus with documented human-to-human transmission, explaining current quarantine measures for disembarking passengers.

There is no specific antiviral therapy—management is supportive, centered on careful fluid management and critical care. Early transfer to a tertiary or quaternary center is essential, as conventional ventilation is often insufficient and veno-arterial ECMO may be life-saving in severe cases.

Dr. Auwaerter closes by encouraging clinicians to consider hantavirus alongside other severe febrile illnesses with thrombocytopenia, such as Rocky Mountain spotted fever, Ehrlichia, and Babesia. The absence of rash and presence of rapidly progressive pulmonary edema can help point toward new world hantavirus, and this outbreak is a reminder to maintain a broad differential even in unexpected settings.

About the Presenter

Paul Auwaerter, MD, MBA

Paul G. Auwaerter is the Sherrilyn and Ken Fisher Professor of Medicine at the Johns Hopkins University School of Medicine serving as the Clinical Director for the Division of Infectious Diseases and Director of the Sherrilyn and Ken Fisher Center for Environmental Infectious Diseases.

He serves as the Executive Director of the Johns Hopkins Point of Care-Information Technology (POC-IT) Center producing the Johns Hopkins Guides – Antibiotic (ABX) (Antibiotic), HIV, Osler, Psychiatry, and Diabetes Guides. In 2018, Dr. Auwaerter served as President for the Infectious Diseases Society of America, the largest professional society worldwide related to infectious diseases.

For More Information

Johns Hopkins Antibiotic (ABX) Guide: https://www.hopkinsguides.com​

Unbound Medicine: https://www.unboundmedicine.com