Natural History of Andes Virus Infection

Inclusion Criteria: 1. No age restriction. 2. Persons diagnosed with or exposed to Andes Virus (ANDV). Exposure must comply with the national definition of ANDV exposure in each country, or satisfy at least one of the following criteria: 1. Direct physical exposure to a person with ANDV infection 2. Environmental and proximity exposure to a person with ANDV infection, i.e.: * Prolonged presence in an enclosed or poorly ventilated shared airspace. Note: Prolonged exposure is defined as cumulative exposure of 15 minutes or more within a 24-hour period in a confined space, or shared occupancy of an enclosed environment for more than 2 hours (ECDC). * Co-habitation in the same household, room, or cabin (e.g., maritime or shared residential settings). * Documented proximity during long-haul travel exceeding 4 hours. Note: Proximity is defined as sitting in an adjacent seat, defined as the same row or within two rows in front or behind. Long haul travel includes flight, bus, car or train. See Box 2 for justification of the 4 hour time threshold. 3. Occupational or caregiving exposure * Provision of direct healthcare or personal care to a person with ANDV infection without the consistent use of recommended Personal Protective Equipment (PPE). * Direct handling of potentially contaminated fomites, such as soiled linens, clothing, or bedding used by a confirmed case. * Direct handling of laboratory samples form a confirmed case with noncompliance with standard biosafety protocols. 3. Ability to comply with confinement sampling and follow up procedures. 4. Informed consent by participant, parent/legal guardian, or surrogate where allowed and applicable; assent or consent for children aged \<18 years or \<16 years as per local regulations. Exclusion Criteria: * 1\. Current imprisonment (quarantine does not count).