Natural History of Andes Virus Infection (NAVIS)

Longitudinal Observational Study of the Natural History of Andes Virus Infection

This is a longitudinal observational cohort study enrolling individuals with a defined exposure to Andes Virus (ANDV) who are confined or quarantined. Subjects can be included in one of the three tiers and are all followed from one tier to the other and/or to end of quarantine: (a) Tier 1 (Exposure/Enrolment): from X0/E0 to P0 (first RT-qPCR positive); (b) Tier 2 (Pre-symptomatic infection): from P0 to S0 (first symptom onset); (c) Tier 3 (Symptomatic disease): from S0 to clinical outcome (clinical resolution or death). Epidemiological information from their exposure (X0) is also collected. The overarching goal is to delineate the natural history and the virologic and immunologic mechanisms and consequences of infection with sampling intensity matched to biological inflection points, i.e., higher frequency around P0 and symptom onset (S0) and lower intensity elsewhere. Clinical care is not directed by the protocol. All medical decisions remain under treating clinicians. This protocol remains observational and purposely low-intensity because it does not direct clinical care, and uses a trigger-based, phase-adaptive tier structure (X0/E0, P0, S0) that limits biospecimen collection to fixed, low-frequency schedules (generally 1-2 collection days/week with step-down to 1 day/week in weeks 5-6 post-trigger) while daily follow-up is restricted to non-invasive clinical monitoring. Participation in the NAVIS protocol does not restrict or prevent enrollment in other Hantavirus-related emergency responses or interventional clinical trials.

Study Overview

• Status: Active, not recruiting
• Conditions: Andes Hantavirus

• Study Type: Observational
• Enrollment (Actual): 15

Contacts and Locations

Study Locations

• France
  • Bordeaux, France, 75018
    • Hôpital Pellegrin
  • Paris, France, 75018
    • Hôpital Bichat
  • Paris, France, 75018
    • La Pitié Salpêtrière

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Consenting persons of any age who have a confirmed exposure to Andes virus and persons with confirmed Andes virus infection who are placed under confinement or quarantine or clinical care for active Andes virus infection. Participation in the NAVIS protocol does not restrict or prevent enrollment in other Hantavirus-related emergency responses or interventional clinical trials.

Description

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).

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to first virologic detection (X0/E0→P0)	Time from enrolment (X0/E0) to first detectable ANDV RNA (P0)	6 weeks
Blood viral kinetics (trajectory endpoints)	Viral load trajectories in blood, including peak, slope of increase/decrease, and time to clearance.	6 weeks
Post-symptom RT-qPCR persistence	Duration of RT-qPCR positivity after symptom resolution (where measured)	6 weeks
Serologic conversion timing	Time to IgM positivity, time to IgG positivity	6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Humoral immune kinetics	IgM and IgG titres over time	6 weeks
Longitudinal immune marker trajectories	Longitudinal immune marker trajectories aligned to P0 and S0 (pre-specified panels)	6 weeks
Symptom onset and symptom duration	Symptom onset date (S0), symptom duration	6 weeks
Clinical severity and healthcare utilisation outcomes	Hospitalisation, ICU admission, organ support (as applicable), mortality (as applicable)	6 weeks
Standardised in-hospital severity metrics (if hospitalised; clinical data only)	WHO Ordinal Scale, SOFA score (if clinically available)	6 weeks
Host genetic correlates of infection and disease outcomes	Genetic associations with infection susceptibility (i.e., infected vs. uninfected among exposed participants). disease severity/progression (e.g., severe vs. mild disease outcomes), key clinical events (e.g., hospitalisation, ICU admission, organ support, mortality) and molecular and immune markers (e.g., differences in viral load kinetics or immune response levels)	6 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Multi-compartment detection and shedding dynamics	Time-to-first-detection in each compartment (blood/buffy coat, plasma if collected, nasopharyngeal swab, saliva, urine, feces) and lead/lag structure relative to P0, compartment-specific kinetic summaries (peak, time-to-peak, growth/decay rates, and AUC) per compartment, compartment-specific time to clearance and discordance patterns (persistence in non-blood compartments after blood clearance, or vice versa).	6 weeks
Trigger-aligned serology endpoints (P0/S0 anchored)	P0→IgM+, P0→IgG+, S0→IgM+, and S0→IgG+ intervals (trigger-aligned seroconversion timing), early titre kinetic features (e.g., early rise patterns) as predictors of downstream clinical outcomes (hypothesis-generating)	6 weeks
Immune "inflection points" and trajectory phenotypes	Earliest detectable immune activation relative to P0 and relative to S0 ("immune inflection point timing"), and peak/resolution kinetics of immune markers, data-driven immune trajectory phenotypes (e.g., clustered longitudinal patterns) and their association with clinical outcomes.	6 weeks
Time-to-event progression endpoints	Time-to-event endpoints such as P0→hospitalisation/ICU and S0→hospitalisation/ICU/organ support/death (as data allow), for early risk modelling and natural history characterization.	6 weeks
Daily monitoring signal summaries	Descriptive trajectories and derived summaries of daily monitoring measures (temperature, SpO₂, blood pressure, diuresis) and their association with subsequent clinical outcomes (hypothesis-generating)	6 weeks
Convalescence and longer-term outcomes	Convalescence pattern descriptors and longer-term outcomes through Month 6 (and beyond if extended), including persistence or resolution patterns as captured in follow-up	6 months

Collaborators and Investigators

• Sponsor: Assistance Publique - Hôpitaux de Paris
• Collaborators: International Severe Acute Respiratory and Emerging Infection Consortium

Study record dates

Study Major Dates

• Study Start (Actual): May 19, 2026
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): August 1, 2026

Study Registration Dates

• First Submitted: July 8, 2026
• First Submitted That Met QC Criteria: July 8, 2026
• First Posted (Actual): July 14, 2026

Study Record Updates

• Last Update Posted (Actual): July 14, 2026
• Last Update Submitted That Met QC Criteria: July 8, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Natural history; Hantavirus; Andes
• Additional Relevant MeSH Terms: Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases; Respiration Disorders; Respiratory Insufficiency; Bunyaviridae Infections; Hantavirus Infections; Hantavirus Pulmonary Syndrome
• Other Study ID Numbers: APHP260690

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Data are available upon reasonable request. The procedures carried out with the French data privacy authority (CNIL, Commission nationale de l'informatique et des libertés) and the european regulation (GDPR) do not provide for the transmission of the database, nor do the information and consent documents signed by the patients. Consultation by the editorial board or interested researchers of individual participant data that underlie the results reported in the article after deidentification may nevertheless be considered, subject to prior determination of the terms and conditions of such consultation and in respect for compliance with the applicable regulations.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No