Viral haemorrhagic fevers

Notification requirement for viral haemorrhagic fevers

Viral haemorrhagic fevers (VHFs) are ‘urgent’ notifiable conditions in Victoria. Medical practitioners and pathology services must notify any suspected or confirmed cases 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.

VHFs are Listed Human Diseases (LHDs) under the Biosecurity Act 2015 (Cth) and are subject to Australian quarantine requirements.

Primary school and children’s services centres exclusion for viral haemorrhagic fevers

Exclude until medical clearance.

Infectious agent of viral haemorrhagic fevers

Four VHFs are of particular concern because they could be imported into Australia and be transmitted to other people, particularly healthcare personnel.

The infectious agents for these quarantinable VHFs are:

• Lassa virus – an arenavirus that causes Lassa fever (LF)
• Crimean–Congo haemorrhagic fever virus – a bunyavirus that causes Crimean–Congo haemorrhagic fever (CCHF)
• Orthoebolavirus (formerly Ebolavirus) – a filovirus that causes Ebola virus disease (EVD)
• Orthomarburgvirus (formerly Marburgvirus) - a filovirus that causes Marburg virus disease (MVD).

Dengue haemorrhagic fever and yellow fever are viral haemorrhagic fevers that are discussed on their respective webpages.

Identification of viral haemorrhagic fevers

Clinical features

Clinically apparent infections with any of these viruses may present with similar symptoms. Fever is typically insidious in onset and accompanied by severe headache, myalgia and malaise.

Other symptoms and signs include retrosternal chest pain, cough, abdominal pain, diarrhoea, conjunctivitis, facial swelling, proteinuria and jaundice. A bleeding diathesis leads to mucosal bleeding, haematemesis, melaena and haematuria.

Severe infections are complicated by massive haemorrhage and multi-organ failure.

Case-fatality rates vary greatly:

• LF has a case-fatality rate of 1 per cent of infected cases but 15 per cent of hospitalised cases with severe disease¹
• CCHF has a case-fatality rate of 10 - 40 per cent²
• MVD has a case-fatality rate of 50 per cent, but case fatality rates have varied from 24 per cent to 88 per cent in past outbreaks³
• EVD has an average case-fatality rate of 50 per cent, but case fatality rates have varied from 25–90 per cent in past outbreaks⁴

Diagnosis

The Department of Health and Victorian Infectious Diseases Reference Laboratory must be consulted for advice and testing approval before the collection and transport of any clinical specimens for diagnostic testing of suspected VHFs.

Clinical specimens are tested at the Victorian Infectious Diseases Reference Laboratory in the highest physical containment (PC4) laboratory conditions in accordance with the Public Health Laboratory Network (PHLN) laboratory procedures and precautions for samples collected from patients with viral haemorrhagic fevers.

Diagnosis is usually made using polymerase chain reaction (PCR) tests, supported by viral isolation and serology. For serology, acute and convalescent samples should be collected.

The preferred clinical specimen for diagnostic testing is whole blood ethylenediaminetetraacetic acid (EDTA) tube for PCR, virus isolation and serology.

If blood collection is not possible, alternative clinical specimens include:

• throat swab (in viral transport medium, screw-capped plastic tube)
• urine sample
• saliva or oral swabs – only if collection can occur safely without inducing vomiting or coughing.

For further information on testing, collection and transfer of clinical specimens, refer to the Victorian guideline on viral haemorrhagic fevers health services guide.

Incubation period of viral haemorrhagic fevers

The incubation period varies according to the causative agent and disease:

• LF - incubation period is 6 to 21 days.
• CCHF – incubation period is 3 to 13 days
• MVD – incubation period is 2 to 21 days.
• EVD – incubation period is 2 to 21 days.

Public health significance and occurrence of viral haemorrhagic fevers

The term ‘viral haemorrhagic fever’ refers to a group of rare illnesses that are caused by several distinct families of viruses. Although some types of haemorrhagic fever viruses can cause relatively mild illnesses, many cause severe, life-threatening disease.

LF, MVD and EVD mainly occur in sub-Saharan Africa, where most human outbreaks have been reported. The origins of MVD and EVD viruses are still unclear, but most cases appear to have arisen in Africa.

CCHF is more widely distributed in Africa, the Mediterranean region, the Middle East, eastern Europe, Central Asia and China.

The high case-fatality rate of these diseases means that it is important for the diagnosis to be made and for the treatment to be commenced as early as possible.

VHFs should be considered in the differential diagnosis of any patient presenting with unexplained fever who has travelled to or resides in an area where VHF is endemic within the past 21 days.

Reservoir for viral haemorrhagic fevers

• The reservoir for Lassa virus is a rodent known as the multimammate rat of the genus Mastomys.
• The reservoirs for CCHF virus are hares, birds and Hyalomma spp. of ticks. Domestic animals such as sheep, goats and cattle may act as amplifying hosts.
• The natural reservoir of Ebola virus is probably African fruit bats. Current evidence suggests that the virus is zoonotic (animal-borne) and is normally maintained in animal hosts native to the African continent. Outbreaks among species such as chimpanzees, gorillas, monkeys and forest antelope occur from time to time.
• Rousettus aegyptiacus fruit bats are considered natural hosts for Marburg virus. Monkeys are susceptible to infection and were the source of infection for humans during the first MVD outbreak. Experimental infections in pigs indicate that that are susceptible to filovirus infection and shed the virus.

Mode of transmission of viral haemorrhagic fevers

Transmission of the VHFs depends on the causative agent and disease:

• Lassa virus is transmitted via exposure to food or household items contaminated with urine or faeces from infected Mastomys (a genus of rodent in the family Muridae endemic to Africa) or directly via contact with infected rats. Person-to-person transmission may occur through direct contact with blood, urine, faeces or other bodily secretions of someone infected with Lassa virus.
• CCHF virus is transmitted by the bite of infective Hyalomma spp. ticks or contact with infected animals. Ticks are believed to acquire the virus by transovarian transmission or from animal hosts. Nosocomial spread to medical workers in contact with infected blood or secretions has been observed. Slaughtering of infected animals is also linked to some infections.
• For Ebola and Marburg viruses, the initial source is often unknown, but secondary transmission occurs through direct contact with infected body fluids or contaminated medical equipment.

Period of communicability of viral haemorrhagic fevers

A person with LF, EVD or MVD is usually not considered to be contagious until the appearance of symptoms. The illness typically progresses from ‘dry’ symptoms (fever, aches and fatigue) to ‘wet’ symptoms (diarrhoea, vomiting and sometimes, bleeding).

The virus’ can survive for several days in soiled clothing bedding and medical equipment and can remain active in the body fluids of a deceased person for several days after death, necessitating strict handling protocols. Ebola and Marburg virus can persist in certain body fluids (specifically semen and urine) for months after recovery, with documented Ebola transmission via semen reported 15 months after clinical recovery, and Marburg virus detected in semen seven months after symptom onset.

Patients with confirmed VHF will be deemed non-infectious by the treating facility’s infectious diseases service, in consultation with the Chief Human Biosecurity Officer as per Section 5.3 ‘De-escalation of isolation’ in the Victorian guideline on viral haemorrhagic fevers Health services guide.

Susceptibility and resistance to viral haemorrhagic fevers

Anyone who is exposed to the viruses that cause viral haemorrhagic fevers can become infected. While these diseases are very rare in Australia, cases can occur in travellers returning from endemic areas.

Control measures for viral haemorrhagic fevers

Preventive measures

While there are two licensed vaccines for Ebola virus (Zaire strain) globally, these are not readily available. There are currently no licensed vaccines for LF, CCHF, MVD or Sudan virus (Ebola species).

Travellers to LF and CCHF endemic areas should avoid contact with rodents and ticks.

Control of case

All cases of suspected or confirmed VHF must be notified to the Local Public Health Unit immediately. Cases must be isolated in a single room, ideally in a negative pressure ventilation room is available and cared for under appropriate infection prevention and control precautions.

All cases of confirmed VHF in Victoria should be managed at a designated health service. All transfers of a suspected or confirmed case will need to be discussed with the Department of Health.

Anyone arriving into Australia who is suspected of or diagnosed with having a VHF is subject to quarantine requirements under the Biosecurity Act 2015 (Cth).

See Victorian guideline on viral haemorrhagic fevers Health services guide Section 3. Management and control of suspected or confirmed cases

Control of contacts

Active case and contact surveillance is conducted by the Local Public Health Unit to identify any other cases and all contacts of the confirmed case.

Health services managing patients with VHF are required to compile a list of patients and staff who engaged with the patient or were in the immediate vicinity of the patient.

Contacts are provided information and education, advised to monitor for symptoms and follow precautions and may be discouraged from traveling during the monitoring period.

Further contact tracing may be advised by the Local Public Health Unit in collaboration with the Department of Health.

Control of environment

Transmission of VHF is primarily from direct contact with body fluids of an infected person. While the environment may become contaminated, spot cleaning of body fluid spills at the time of contamination minimises the risk of transmission. Procedures that increase environmental contamination with blood or body fluids should, wherever possible, be avoided.

All potentially contaminated personal items, items used in the treatment of the patient, and the patients room should be disinfected, and waste managed according to the Victorian guideline haemorrhagic fevers health services guide. See Section 5. IPC for detailed processes for IPC and environmental cleaning. 

Outbreak measures for viral haemorrhagic fevers

A single case of any of these VHFs in any setting would constitute an outbreak, and requires the clinical and public health control measures outlined above.

International measures

In the event of a suspected or confirmed case of VHFs, the Department of Health would immediately notify the Commonwealth Chief Medical Officer, who would in turn notify the World Health Organization in accordance with the International Health Regulations 2005. Health authorities in other jurisdictions may be notified based on identified exposures.

References

1. World Health Organization, Lassa Fever factsheet, accessed 1 April 2026.
2. World Health Organization, Crimean-Congo haemorrhagic fever factsheet, accessed 1 April 2026.
3. World Health Organization, Marburg virus disease factsheet, accessed 1 April 2026.
4. World Health Organization, Ebola disease factsheet, accessed 1 April 2026