India faces no immediate public health threat from hantavirus: NIV chief

New Delhi: Amid concerns over two Indian nationals reportedly infected with the hantavirus aboard a cruise ship, Director of the ICMR's National Institute of Virology Dr Naveen Kumar on Friday said the cases appear to be isolated ones and there is no immediate public health threat to India.

Kumar said there is no evidence of community spread as of now.

Hantaviruses are mainly transmitted to humans through contact with infected rodents or their excreta such as saliva, urine and faeces, he told PTI.

People usually get infected by inhaling aerosolised virus particles from rodent urine, droppings, or saliva in closed or poorly ventilated spaces such as warehouses, ships, barns and storage areas, he said.

"The reported hantavirus cases appear to be isolated ones and there is no immediate public health threat to India," he said.

His remarks come after reports that two Indian nationals aboard a cruise ship were detected with hantavirus.

According to the World Health Organisation (WHO), the two Indian passengers were among a small cluster of suspected infections identified aboard the vessel, and health authorities were monitoring contacts and undertaking precautionary measures.

WHO officials noted that hantavirus infections are rare and are generally linked to rodent exposure rather than sustained human transmission.

Kumar stressed that unlike Covid-19, hantavirus does not spread easily among people.

"Human-to-human transmission is extremely uncommon. Most hantaviruses, especially those reported in Asia and Europe, do not spread between humans. Limited person-to-person transmission has only been documented with some South American strains such as Andes virus," he explained.

WHO Director General Dr Tedros Adhanom Ghebreyesus, who briefed the media on the virus, said "while this is a serious incident, WHO assesses the publich health risk as low".

Given the incubation period, he said, "it is possible that more cases may be reported".

Public health experts say hantavirus infections can initially resemble influenza, dengue or severe respiratory illness, making early diagnosis challenging.

On India's preparedness, Kumar said the country has adequate laboratory surveillance capacity to identify suspected cases.

"India has diagnostic capacity for hantavirus infection through the ICMR-National Institute of Virology and the nationwide Viral Research and Diagnostic Laboratory Network of 165 labs, where RT-PCR facilities are available for confirmation of suspected cases," he said.

According to Kumar, symptoms generally appear one to five weeks after exposure and initially resemble flu-like illness.

"Common warning signs include sudden fever, severe body ache, headache, fatigue, chills, nausea, vomiting, abdominal pain and dry cough," he said.

"In severe cases, patients may develop breathing difficulty, low blood pressure, or kidney involvement with reduced urine output," he added.

The NIV director advised people working or travelling in rodent-prone environments such as ships, warehouses, storage facilities and poorly ventilated spaces to maintain hygiene and avoid exposure to rodent-infested areas.

Kumar also cautioned that environmental changes could increase the long-term risk of rodent-borne diseases globally, including in India.

"Climate change, flooding, unplanned urbanisation, poor waste management and increased human encroachment into rodent habitats can raise the risk of rodent-borne infections," he said.

"Heavy rainfall and floods often increase rodent population movement into human dwellings and storage areas, increasing exposure risk. Rapid urban growth with poor sanitation can further support rodent proliferation," Kumar added.

He, however, underlined there is currently no indication of widespread transmission linked to the cruise ship cases and that standard rodent-control and sanitation measures remain the key preventive strategies against hantavirus.