Andes virus, a species of New World hantavirus with similar symptoms and a fatality rate as others, is transmitted to humans primarily through contact with long-tailed rice rats (Oligoryzomys longicaudatus), which are endemic to much of Argentina and Chile.

Argentina/CIA
Argentina/CIA

According to a Centers for Disease Control and Prevention (CDC) Morbidity and Mortality Weekly Report (MMWR), the first imported human case of the virus has been reported in the United States.

According to the report:

A woman admitted to a Delaware hospital in January tested positive for New World hantavirus immunoglobulin M (IgM) and immunoglobulin G (IgG) by enzyme-linked immunosorbent assay (ELISA). Subsequent testing by CDC’s Viral Special Pathogens Branch detected New World hantavirus by nested reverse transcription–polymerase chain reaction (RT-PCR) and Andes virus by nucleic acid sequencing.

Before her illness, the patient had traveled to the Andes region of Argentina and Chile from December 20, 2017, to January 3, 2018. She stayed in cabins and youth hostels in reportedly poor condition. No rodent exposures were reported. After returning to the United States on January 10, she developed fever, malaise, and myalgias on January 14. On January 17, while ill, she traveled on two commercial domestic flights. She was hospitalized during January 20–25 in Delaware and discharged to her home after clinical recovery.

51 of the 53 contacts were identified in six states- 28 were health care personnel, 15 were airline contacts (flight crew who served the traveler and passengers seated within one seat of the traveler), and eight were other contacts of the traveler (including acquaintances and a hospital roommate).

Two contacts were considered high-risk: a health care worker who had contact with the woman’s sweat and a family member who had contact with her bedding and clothing. Neither showed symptoms of infection.

CDC notes that unlike other hantaviruses, Andes virus can be transmitted from person to person; however, transmission is typically limited to close contacts of ill persons.

In addition to this imported case in the US, two imported cases have been reported in Switzerland.