A cruise ship outbreak linked to hantavirus has sparked fresh questions about how worried the public should really be. With reports of fatalities and a strain capable of limited human-to-human transmission, the headlines have understandably raised alarm.
However, the World Health Organisation has clarified that this is not considered the start of another pandemic, noting that hantaviruses behave differently from highly transmissible respiratory viruses such as COVID-19. Even so, health experts caution that certain strains can be severe, with reported mortality rates reaching 30 to 40%.
Speaking on the subject, Dr Lee Kok Soon, Consultant Physician and Infectious Diseases Specialist at Sunway Medical Centre, Sunway City, says hantavirus itself is not new.
It has been known for decades and continues to be reported in parts of Asia, Europe and the Americas, where rodent-borne infections occur each year. He notes that heightened concern is understandable in a post-pandemic environment, but stresses the importance of understanding how the virus actually spreads.
The Different Strains and Risks
Hantavirus is not a single virus but a group of related viruses carried by rodents. Different strains affect the body in different ways. Some mainly target the lungs, leading to Hantavirus Pulmonary Syndrome, which can cause rapid fluid build-up in the lungs and severe breathing failure. Others, more common in Europe and Asia, are linked to kidney complications and haemorrhagic fever with renal syndrome.
The recent outbreak has drawn global attention due to the involvement of the Andes strain, one of the few hantavirus strains associated with limited human-to-human transmission. However, experts stress that its transmission mechanism remains vastly different from that of respiratory viruses such as COVID-19.
In everyday settings, the main risk comes from contact with environments contaminated by infected rodents such as rats and mice. The virus can spread when microscopic particles from rodent urine, saliva or droppings become airborne and get inhaled. In rare instances, transmission may also occur through rodent bites or scratches.
Dr Lee points out that even basic actions like sweeping or vacuuming a rodent-infested storeroom can disturb contaminated dust and release particles into the air. For this reason, he advises against dry sweeping in high-risk areas such as abandoned buildings, long-unused storage spaces or places affected by poor sanitation.
Instead, he recommends first spraying such areas with disinfectant, allowing it to sit for several minutes, and then cleaning with a damp cloth to reduce airborne particles. Protective steps such as wearing gloves and masks, proper waste disposal and ensuring good ventilation can further lower exposure risk.
Knowing the Symptoms And the Importance of Awareness
One of the challenges with hantavirus infection is that early symptoms often resemble those of common illnesses. Patients may initially experience fever, body aches, fatigue, nausea or dizziness, which can easily be mistaken for influenza, dengue, leptospirosis or COVID-19.
“Exposure history becomes an important clue, especially if the patient has recently been in rodent-infested or poorly ventilated environments,” he says.
Diagnosis relies on clinical assessment, supported by laboratory tests and imaging. In more severe respiratory cases, chest scans can show fluid in the lungs, while blood tests may detect abnormalities in platelet count, kidney function, or liver function. Doctors confirm the infection through specialised tests such as PCR or antibody testing.
There is currently no specific antiviral treatment for hantavirus infection. Care focuses on early medical attention and supportive treatment, particularly because the condition can deteriorate rapidly once severe respiratory symptoms develop. In more serious cases, patients may need oxygen therapy, intensive care support, or dialysis, depending on which organs are affected.
While Malaysia has not reported any hantavirus outbreaks, Dr Lee says recent global developments highlight the importance of remaining vigilant against rodent-borne diseases. He encourages households to maintain clean living environments, store food securely and take extra care when cleaning dusty or neglected areas, particularly after floods, renovations or prolonged disuse.
“Simple preventive habits and safe cleaning practices can significantly reduce exposure risks. If symptoms worsen after possible rodent exposure, it is important to seek medical attention early,” he adds.
