Hemorrhagic fever with renal syndrome (HFRS) is caused by which group of hantaviruses?

• A. Old World hantaviruses
• B. New World hantaviruses
• C. Both
• D. Neither

Answer: (A)

Old World hantaviruses cause hemorrhagic fever with renal syndrome. Viruses like Hantaan, Seoul, Puumala, and Dobrava-Blaška are carried by rodents in Europe and Asia and lead to fever, hemorrhage, and renal impairment. New World hantaviruses, such as Sin Nombre, cause hantavirus pulmonary syndrome with prominent respiratory failure rather than renal involvement. Therefore, hemorrhagic fever with renal syndrome is linked to Old World hantaviruses, making that the correct association.