In light of the recent cluster of Hantavirus (Andes strain) infections reported by the DGS, we would like to provide you with an update.
Epidemiology of Hantaviruses
Hantaviruses are zoonotic viruses transmitted primarily through the inhalation of aerosols contaminated with rodent excreta; human-to-human transmission remains rare and has been reported mainly for the Andes virus (close and prolonged contact). Hantaviruses that are pathogenic to humans are classified into Group 2 (such as Puumala viruses and the strains most commonly found in France) and Group 3 (such as Seoul and Andes viruses). There is no specific treatment or approved vaccine.
Alert May 2026
A cluster of cases has been identified on board a ship, with confirmation of infection with an Andes-type hantavirus (ANDV). At this stage:
-
the risk to the general population is considered low,
-
no evidence of community transmission in France has been identified,
-
measures mainly concern identified contacts who are being monitored by the ARS.
-
Clinical reminders regarding Hantavirus infections
Risk exposures
-
Direct contact with infected rodents
-
Indirect contact with objects or surfaces contaminated with urine, faeces or saliva from infected rodents
-
Inhalation of aerosolised virus from the excretions of infected rodents
-
Exposed workers: construction workers, farmers or forestry workers
After an incubation period of 1 to 6 weeks, the infection typically begins with a non-specific flu-like syndrome (fever, aching muscles, fatigue).
Gastrointestinal or respiratory symptoms may also be present.
In severe cases, progression to haemorrhagic fever with renal syndrome (HFRS) is possible with European strains, whereas with American strains of the Andes type, progression to haemorrhagic pulmonary syndrome (HPS) is observed.
Laboratory diagnosis: practical considerations
-
Diagnosis is based on serology (IgM/IgG) and/or molecular detection (RT-PCR).
-
Screening serology for the diagnosis of hantaviruses is performed by indirect immunofluorescence and covers several European and American viral species (including Andes).
Serology enables, in particular, the detection from day 3 following the onset of symptoms of:
-
The presence of anti-Hantavirus IgG and IgM antibodies, indicating a recent or past infection
-
Seroconversion to IgM and/or IgG
Specific features of the Andes strain (ANDV)
To date, diagnostic confirmation of the Andes strain remains centralised at the National Reference Centre for Hantaviruses (Institut Pasteur). Only the NRC is able to carry out this diagnostic confirmation and will shortly issue guidelines regarding the handling of suspect samples. Procedure
Consequently, any result found to be positive by the Biomnis screening serology will be sent to the CNR for confirmation and species typing
Differential diagnoses
Due to the non-specific clinical presentation and the presumed geographical area of infection, numerous differential diagnoses may be considered:
Any result found to be positive by the Biomnis screening serology test will therefore be forwarded to the CNR for confirmation and species typing
Differential diagnoses
Due to the non-specific clinical presentation and the presumed geographical area of infection, numerous differential diagnoses may be considered:
- Leptospirosis
- Dengue
- Chikungunya
- Hepatitis A and E
- Typhoid fever
- Coxiella infection – Q fever
- Influenza virus
- SARS-CoV-2 – COVID-19
- Rickettsial diseases
- Malaria
If an infection with an Andes-type hantavirus is suspected, it is recommended that the patient be isolated.