90-Second Read: Andes Virus Shifts Hantavirus Conversation for US Labs

Emerging Andes virus cases are prompting US clinical labs to reassess Hantavirus protocols and consider exposures beyond rodent contact. Recent Andes virus cases, however, are prompting laboratories to revisit how they think about Hantavirus exposure and transmission. Despite the recent attention, Hantavirus remains rare in the US, with fewer than 900 cases reported between 1993 and 2023, according to Talbot. May 22, 2026 | Emerging & Zoonotic Diseases, Infectious Diseases, Molecular Diagnostics | For most laboratorians in the United States, Hantavirus has long been synonymous with Sin Nombre virus, a pathogen transmitted through contact with the urine or feces of infected rodents.

That timing makes serology especially useful in routine Hantavirus diagnosis, since most patients seek care after symptoms begin. Less commonly encountered Hantavirus strains such as Andes virus can create additional challenges for laboratories, particularly around test availability and interpretation. Hantaviruses share antigenic similarities, which is useful for screening but can make it difficult to differentiate between Sin Nombre and Andes virus. According to Stiba, patients typically present with findings like fever, myalgias, thrombocytopenia, and leukocytosis, which can resemble more common viral illnesses such as influenza or COVID-19.

Unlike Sin Nombre virus, Andes virus can also spread through respiratory secretions from an infected person. As a result, experts do not expect Hantavirus testing to become common in most clinical laboratories. Most hospital laboratories do not perform definitive Hantavirus testing onsite. Many commercial serologic assays were developed with other Hantavirus strains in mind.

Stiba says recent infectious disease outbreaks have reinforced the importance of preparing before rare pathogens appear. While these tests can often detect infection through cross-reactivity, they may not identify the specific virus involved. But Stiba says they still play an important role in identifying possible cases, following appropriate specimen handling precautions, coordinating send-out testing, and communicating with infection prevention and public health officials.