Hantavirus is a potentially life-threatening viral infection primarily spread through contact with infected rodents. Individuals with weakened immune systems, such as cancer patients and organ transplant recipients, are at greater risk for severe complications, including Hantavirus Pulmonary Syndrome (HPS) and Hemorrhagic Fever with Renal Syndrome (HFRS). These conditions can lead to rapid respiratory failure and multi-organ damage. The infection has a 10 to 50% case fatality rate, even among healthy individuals, but the risks are exacerbated in immunocompromised patients due to their weakened defense mechanisms. Symptoms often start mild, resembling those of common viral illnesses, which can delay diagnosis and treatment. Supportive care, including oxygen therapy and fluid management, is the primary treatment, as there is currently no specific antiviral cure. Preventive measures, such as avoiding rodent exposure and maintaining cleanliness in living spaces, are crucial for reducing risks, especially for vulnerable populations.