Key Messages
- Hantaviruses are zoonotic viruses carried by rodents that can result in severe disease and death.
- Transmission to humans can occur through contact with rodents, their saliva, urine or droppings and rodent infested environments.
- Human-to-human transmission has only been documented with Andes virus.
- Hantavirus infections can present as Hantavirus Pulmonary Syndrome Americas or Haemorrhagic Fever with Renal Syndrome.
- The risk of hantavirus infection in Australia is very low. There has never been a recorded case of hantavirus infection in humans or animals in Australia.
- Medical practitioners should seek testing and management advice from an infectious diseases specialist and/or Local Public Health Unit for patients with compatible illness and risk factors.
- Hantavirus infection is an urgent notifiable condition for medical practitioners and pathology services and must be notified immediately to the Department of Health.
Notification Requirements for Hantaviruses
Hantavirus infection is an urgent notifiable condition in Victoria.
Medical practitioners and pathology services must notify any suspected or confirmed hantavirus infections immediately to the Department of Health by calling 1300 651 160 (24/7) and connecting to the relevant Local Public Health Unit. Pathology services must follow up with written notification within 5 days.
This is a Victorian statutory requirement.
Infectious Agent for Hantaviruses
Hantaviruses are a group of zoonotic viruses belonging to the Hantaviridae family. Rodents are the natural reservoirs. Each hantavirus has its own specific rodent reservoir species.
Only a limited number of hantaviruses cause human disease such as the Andes and Sin Nombre viruses in the Americas and Puumala and Dobrava viruses in Europe.
Identification of Hantaviruses
Clinical Features
Hantavirus infections can present as distinct clinical syndromes.
Hantavirus Pulmonary Syndrome is often seen in the Americas. Early clinical features may include:
- fever or chills
- headache
- muscle aches
- gastrointestinal symptoms such as abdominal pain, nausea and vomiting.
There is often a rapid progression (typically within 4 to 10 days) to severe lower respiratory tract involvement characterised by:
- cough
- progressive dyspnoea
- chest tightness
- pulmonary oedema
- hypoxia.
Haemorrhagic Fever with Renal Syndrome is often seen in Asia and Europe. Early clinical features may include:
- fever or chills
- muscle aches
- gastrointestinal symptoms
- blurred vision
- flushed face
- inflammation or redness of the eyes
- rash.
Later clinical features may include:
- acute kidney injury
- vascular leakage
- hypotension
- shock.
Disease severity varies depending on the virus species and region. Case fatality rates are about <1 to 15 per cent in Asia and Europe but can reach up to 50 per cent in the Americas.
Diagnosis
Diagnosis can be confirmed through:
- nucleic acid amplification testing (NAAT)
- hantavirus serology (IgM and IgG).
Recommended specimens for testing include EDTA blood and serum. Samples should ideally be collected early in illness. For serology, baseline and convalescent samples (at least 10 to 14 days later) should be collected.
In Victoria, testing is available through the Victorian Infectious Diseases Reference Laboratory and must be approved by the Department of Health. For more information on testing, visit the VIDRL website.
Clinicians should seek testing advice from an infectious diseases specialist and/or Local Public Health Unit for patients with compatible clinical illness and epidemiological risk factors for hantavirus infection.
Incubation Period of Hantaviruses
The incubation period ranges from 1 to 8 weeks, depending on the virus species.
Public Health Significance and occurrence of Hantavirus infections
Hantavirus infections occur globally, with estimated global incidence ranging from 10,000 to over 100,000 cases annually. The highest burden of hantavirus infections is in Asia, Europe and the Americas.
The risk of hantavirus infection being detected in Australia is very low. There has never been a recorded case of hantavirus infection in humans or animals in Australia.
The Department of Health closely monitors for zoonotic disease outbreaks worldwide through our collaboration with national and international human and animal health organisations.
Reservoir for Hantaviruses
Rodents are the natural reservoir for hantaviruses. Different hantavirus species are associated with different rodent species.
Mode of Transmission of Hantaviruses
Transmission of hantaviruses to humans occurs through:
- contact with rodents and their saliva, urine or droppings
- breathing in contaminated dust or aerosols in rodent infested areas
- contact with items or materials that have been contaminated with bodily fluids from rodent.
Less commonly, infections can occur from rodent bites. Activities that result in contact with rodents including farming or forestry work, sleeping in rodent-infested environments or cleaning in rodent-occupied spaces, increase the risk of exposure to hantavirus.
Human-to-human transmission has only been documented for Andes virus species of hantavirus and is more likely to occur early in the infection. This can occur from:
- close, prolonged contact with someone with hantavirus infection with Andes virus
- contact with their blood, tissues, bodily fluids (such as urine, vomitus or stool) and respiratory secretions, including laboratory specimens
- contact with contaminated surfaces and objects including the case’s clothes, linens or other personal items.
Transmission may also occur through the inhalation of respiratory droplets or aerosolised viral particles.
Period of Communicability of Hantaviruses
Only Andes virus has demonstrated the ability for human-to-human transmission. The period of communicability for Andes virus is unknown.
Control Measures for Hantaviruses
Preventative Measures
There is no vaccine available to protect against hantavirus infection.
People travelling overseas are advised to check travel advice and notices prior to travel on Smartraveller.
Measures to reduce the risk of exposure when travelling to areas where hantavirus is being detected include the following:
- avoid contact with rodents, their saliva, urine and droppings and rodent infested environments
- practice good hand washing, especially after touching animals and visiting people who are sick.
Control of Case
There is currently no specific treatment available for hantavirus infection. Treatment is supportive and aimed at managing symptoms and complications. Medical practitioners should seek treatment advice from an infectious diseases specialist.
Infection Prevention and Control guidance for Andes virus
Patients with suspected or confirmed hantavirus infection with Andes virus should be isolated in a single room with a private bathroom and managed under standard, contact and droplet precautions. The patient should wear a surgical mask if tolerated. Adequate indoor ventilation should be ensured.
Escalation to management in a negative pressure room under airborne precautions (P2 or N95 respirator) should occur in cases of severe respiratory illness or if aerosol generating procedures are required.
The level of required PPE will depend on the patient’s infection risk.
Control of Contact
Andes virus has demonstrated ability for human-to-human transmission. Contacts of cases of hantavirus infection with Andes virus are followed up by Local Public Health Units.
Contacts are stratified into high and low risk contacts. Advice for contacts may include:
- quarantine for up to 42 days
- self-monitoring for symptoms daily and performing a daily temperature check
- active follow up by the Local Public Health Unit for daily symptom and temperature check
- contacting the Local Public Health Unit immediately if they become symptomatic
- exclusion from sensitive settings.
Control of Environment
Hantaviruses have never been detected in humans or animals in Australia.
Outbreak Measures for Hantaviruses
A single confirmed case of hantavirus infection would be considered an outbreak.
Case(s) would be investigated to determine the likely source of infection through a detailed history of their work and movements. Further cases may be identified through active case finding. Contacts would be identified, monitored and provided public health advice.
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