# Incubation period

> Interval between exposure to a pathogen and the onset of the first symptoms. For Andes virus: 7 to 42 days, on average 18 to 24 days.

Canonical source: https://hantatracker.fr/en/glossary/incubation-period/

**Aliases**: incubation, incubation time, incubation period

The **incubation period** is the interval between exposure to a pathogen and the onset of the first symptoms in the infected person. For the **Andes virus** responsible for the MV Hondius event, it ranges from **7 to 42 days**, with an average of **18 to 24 days**. This is the longest range observed for a hantavirus, which shapes the entire surveillance arrangement for passengers and contacts.

## Definition and mechanism

### Definition

The incubation period corresponds to the interval between the penetration of the infectious agent into the organism and the moment it manifests clinically. It depends on several parameters: virulence and tropism of the agent, infectious dose received, route of entry, immune status and age of the person, genetic variability between strains.

### Distinction from other durations

Incubation is to be distinguished from the **latent period** (interval between infection and the start of contagiousness) and the **infectious period** (interval during which the person is contagious). For hantavirus diseases, contagiousness only begins with symptom onset — there is no documented transmission during the asymptomatic phase.

## Incubation period of hantavirus diseases

### Andes virus

Andes virus has the longest incubation period among known hantaviruses: **7 to 42 days**, on average 18 to 24 days. This feature requires extended surveillance of exposed persons: 42 days after the last possible exposure.

### Other strains

Other hantaviruses show similar but variable durations:
- **Sin Nombre virus** (North America): 1 to 5 weeks, on average 2 to 3 weeks.
- **Eurasian hantaviruses** (Hantaan, Seoul, Puumala): 1 to 8 weeks for hemorrhagic fever with renal syndrome.

WHO uses an overall range of 1 to 8 weeks for human hantavirus diseases as a whole.

## Consequences for surveillance

### Quarantine and follow-up duration

The international rule is to **follow contacts for the maximum known incubation duration** of the disease. For Andes virus, this is **42 days**. This duration is three times longer than that used for COVID-19 (14 days) or Ebola (21 days), mobilising health resources for nearly six weeks.

### Application to MV Hondius

For the 149 people disembarked in Tenerife (Granadilla de Abona) on 10 May 2026, the surveillance window ends at the end of June 2026. Throughout this period, the health authorities of the 10 countries concerned actively follow contacts: daily symptom surveillance, direct access to a referral physician, immediate isolation upon onset of any suggestive sign.

### Why this duration is reassuring

The longer the incubation period, the wider the window of opportunity to intercept a symptomatic case before it infects those around them. Combined with active surveillance and person-to-person transmission accounting for only 2 to 5% of cases, the WHO assessment of risk to the general population as "low" rests partly on the operational relevance of this prolonged surveillance.