Kerala Health Authorities Monitor Hantavirus as Potential Emerging Pathogen

Kerala health officials are evaluating the potential emergence of hantavirus (Orthohantavirus) as a human pathogen following evidence of past exposure and rising concerns over misdiagnosis amid leptospirosis-like cases. The state has documented hantavirus seropositivity in multiple studies since 2008, including a probable case of hantavirus-induced hemorrhagic fever with renal syndrome (HFRS) in 2014 that lacked confirmatory testing.

Clinicians note that symptoms of hantavirus-induced HFRS—high fever, myalgia, thrombocytopenia, acute kidney injury, and hemorrhagic manifestations—are nearly identical to those of leptospirosis, making differential diagnosis without specific serology or PCR testing extremely difficult. A December 2025 study at Lisie Hospital, Kochi, found 16.2% of 216 febrile patients positive for anti-orthohantavirus IgM antibodies, suggesting prior or recent exposure.

The Institute of Advanced Virology (IAV) in Thiruvananthapuram has now established PCR testing to confirm hantavirus infections, closing a critical diagnostic gap. Despite routine testing of clinical samples from Government Medical College, Thiruvananthapuram, no confirmed cases have been detected so far, according to IAV Director E. Sreekumar. The institute has also initiated basic virological research on circulating strains.

Health experts stress that while hantavirus may be circulating undetected, there is no current public health emergency, as no human-to-human transmission has been reported and diagnostic capabilities have improved. The IAV will continue surveillance and expand testing as part of routine diagnostics for febrile illness cases negative for leptospirosis.