Viral Haemorrhagic Fevers (Quarantinable)

Queensland Health Guidelines for Public Health Units

Revision History

• Infectious Agent
• Case Definitions and Notification Criteria
• Notification Procedure
• Objectives of surveillance
• Public Health Significance and Occurrence
• Clinical Features
• Reservoir
• Mode of Transmission
• Incubation Period
• Period of Communicability
• Susceptibility
• Management
• References
• Appendices

Infectious Agent

Viral haemorrhagic fever (VHF) refers to a group of rare but potentially life-threatening illnesses caused by a range of RNA viruses.

Dengue haemorrhagic fever is the only VHF known to occur in Australia.

This guideline applies to quarantinable VHF caused by the following viruses, as well as emerging species:

• Ebola virus and Marburg virus (filoviruses)
• Lassa and Lujo virus (arenavirus)
• Crimean-Congo haemorrhagic fever virus (bunyavirus)

Case Definition and Notification Criteria

For surveillance purposes, only probable and confirmed cases are notified to the National Notifiable Diseases Surveillance System (NNDSS).¹

A single VHF case under investigation is an emergency requiring immediate jurisdictional notification.²

Confirmed case¹

A confirmed case requires laboratory definitive evidence only.

Laboratory definitive evidence

Isolation of a specific virus

OR

Detection of specific virus by nucleic acid testing or antigen detection assay

OR

IgG seroconversion or a significant increase in antibody level or a fourfold or greater rise in titre to specific virus.

Laboratory definitive evidence requires confirmation by the Victorian Infectious Diseases Reference Laboratory (VIDRL), Melbourne, or the Special Pathogens Laboratory, CDC, Atlanta, or the Special Pathogens Laboratory, National Institute of Virology (NIV), Johannesburg.

Probable case¹

A probable case requires laboratory suggestive evidence AND clinical evidence AND epidemiological evidence.

Laboratory suggestive evidence

Isolation of virus pending confirmation by VIDRL, Melbourne, or CDC, Atlanta or NIV, Johannesburg

OR

Detection of specific virus by nucleic acid testing, pending confirmation by VIDRL, Melbourne or CDC, Atlanta or NIV, Johannesburg

OR

IgG seroconversion or a significant increase in antibody level or a fourfold or greater rise in titre to specific virus pending confirmation by VIDRL, Melbourne or CDC, Atlanta or NIV, Johannesburg

OR

Detection of IgM to a specific virus.

Clinical evidence

A clinically compatible illness as determined by an infectious diseases physician which may include the following:

• fever or history of fever
• myalgia and prostration
• headache
• pharyngitis
• conjunctival infection
• flushing
• vomiting, diarrhoea, abdominal pain
• spontaneous bleeding, petechiae, hypotension and shock, oedema, and neurologic involvement.

Epidemiological evidence

History of travel to an endemic/epidemic area within 9 days (Marburg), 13 days (Crimean-Congo virus) or 21 days (Lassa virus, Ebola virus) of illness onset. Filoviruses are endemic in Sub-Saharan Africa, Crimean-Congo virus in Africa and the Middle East to West China;

OR

Contact with a confirmed case

OR

Exposure to viral haemorrhagic fever (VHF)-infected blood or tissues.

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Notification Procedure

Pathology Laboraties

To notify immediately (i) on request for testing, and (ii) on pathological confirmation, by usual means.

Attending Medical Practitioners/Medical Superintendents (or delegates)

Clinicians urgently notify by phone to public health unit (PHU) on clinical suspicion.

The public health unit should immediately notify the Chief Health Biosecurity Officer who will liaise with the Director of Human Biosecurity (Commonwealth Chief Medical Officer) as required.

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Objectives of Surveillance

1. To rapidly identify, isolate and treat cases so that appropriate measures can be taken to prevent further transmission.
2. To identify and provide information to contacts and ensure that they are isolated rapidly should symptoms occur.²

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Public Health Significance and Occurence

VHF is of high public health consequence due to outbreak potential with high case fatality rates and bioterrorism risk.

Sporadic human disease and outbreaks of Ebola and Marburg virus most commonly occur in Central and West Africa and rarely in travellers or evacuated patients from epidemic areas. The West African Ebola epidemic between 2014 to 2016 was the largest recorded outbreak of approximately 28,000 cases with case fatality rates of up to 90%.³ Four of the six Ebola viruses and the single Marburg virus species are responsible for human disease.⁴

Lassa fever is known to be endemic to West Africa, particularly Guinea, Liberia, Nigeria, Sierra Leon, Benin, Mali, Ghana and Togo.⁵ Crimean-Congo haemorrhagic fever virus is more widely distributed across Africa, the Mediterranean, the Middle East, Eastern Europe, central Asia, China and the Indian subcontinent.⁶

Travel is a key factor in the emergence of sporadic disease or multi-country outbreaks. Case importations to non-endemic countries have occurred without subsequent disease outbreaks.²

Lack of health infrastructure and competing health emergencies contribute to the size and severity of VHF outbreaks in endemic countries.⁷

VHF is a listed human disease under both the Biosecurity Act 2015⁸ and the National Health Security Act 2007.⁹

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Clinical Features

Reservoir

Lassa fever – Mastomys rats.⁵

Crimean-Congo haemorrhagic fever – Hyalomma ticks are both a reservoir and vector for the disease. Other hosts include a range of wild and domestic vertebrate animals such as cattle, sheep, goats or ostriches.^12,13

Marburg virus disease – Egyptian fruit bats (Rousettusaegyptii) (cave dwelling bats) are considered the natural host. Incidental infection without disease has been identified among several primate species.⁴

Ebola virus disease – Fruit bats of the Pteropodidae family are hypothesised to be natural Ebola virus hosts.¹⁴

Lujo haemorrhagic fever – Rodents¹⁵

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Mode of Transmission

Zoonotic transmission
Lassa Fever and Lujo Fever transmission occurs through direct or indirect contact with rodent urine or faeces via ingestion, inhalation or mucosal membrane exposure.^5,15,16 Crimean-Congo haemorrhagic fever transmission occurs via contact with an infected tick (including bite or squashing of a bite on skin) or blood or body fluids slaughtering or butchering practices or consumption of meat or unpasteurised milk of an infected animal.¹⁷ Contact with blood, tissue or body fluids of an infected mammal (Ebola) or interference with bats or bat habitats such as caves (Marburg) is associated with initial transmission to index cases.⁴

Person to person transmission
Human to human transmission of VHFs is associated with direct or indirect contact with infected blood, tissue, organs or body fluids including urine, vomit, diarrhea, secretions, or semen from people with, or who have recovered from, or have died from VHF. This may be the result of breaches in skin integrity, mucous membranes, ingestion, sexual contact or maternal transmission or by contaminated objects and environmental surfaces. Outbreak transmission is commonly linked to health care or caregiving when patients are experiencing vomiting, diarrhoea, haemorrhage or burial preparation practices of deceased.¹⁸ Sexual transmission of VHFs is documented, with virus detected in semen reported for months, or up to 203 days (Marburg) after disease onset. ^{4,6,11,14,19,20}

There is no evidence of human-to-human transmission of VHF via droplet or aerosol transmission, however, aerosol-generating procedures and/or behaviours may present a risk to HCW due to environmental viral load¹⁸.

Percutaneous exposure is commonly reported in the transmission of Crimean-Congo Haemorrhagic Fever among health care workers.¹⁷

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Incubation Period

Lassa fever: commonly 6–21 days⁵

Ebola virus disease: 2–21 days¹⁴

Marburg virus disease: usually 3–10 days, but longer incubation periods of 21 days (and rarely up to 28 days) have been reported^21,22

Crimean-Congo haemorrhagic fever: Usually 1–3 days, maximum 14 days.¹⁹ A shorter incubation period is associated with tick borne exposure²³

Lujo haemorrhagic fever: Usually 7–13 days.¹⁵

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Period of Communicability

Cases are infectious at the onset of symptoms and can remain infectious as long as virus is present in blood and body fluids. Communicability increases with the progression of disease and ‘wet’ symptoms to the highest at point of death.^2,4,5,14

Eyes, central nervous system, placenta and semen are sites known to demonstrate persistent Ebola virus detection.²⁴

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Susceptibility

Susceptibility to VHF is universal. The duration of immunity following infection is unknown. Reinfection of Crimean-Congo haemorrhagic fever virus has not been recorded.²³

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Management

Case under investigation

• fever or history of fever in the prior 24 hours

AND

• epidemiology, including
  • return from a country or geographical area where there is a current VHF outbreak, or VHF is endemic, within 21 days of illness onset.

  OR

  • reported contact with a known or highly suspected case of VHF within the 21 days of illness onset.

If patient does not have epidemiological risk, VHF is unlikely, and an alternate diagnosis should be investigated. Caution should still be applied if epidemiological risk is present in the absence of fever as onset of fever may be abrupt. Clinical judgement should be applied.

A case under investigation should be isolated in a single room (with the door closed where possible) and managed with contact (enhanced) and airborne precautions whilst continuing with additional risk assessment.

Consider first the symptom onset and specific virus type incubation period. If not consistent, VHF is unlikely, and an alternate diagnosis should be investigated. If consistent, consider the following:

• clinical signs and symptoms such as vomiting, diarrhoea, new bruising or new bleeding that commenced after the onset of illness and are without an alternative explanation
• contact with body fluids (blood, urine, faeces, tissues, laboratory specimens) from an individual or animal known or strongly suspected to have VHF
• participated in a funeral which involved direct contact with the deceased body
• additional disease burden information eg: travel to an area with a known current VHF outbreak.
• lived or worked in basic rural conditions in an area where Lassa fever is endemic
• visited caves or mines, or had contact with or eaten primates, antelopes or bats in a Marburg Virus Disease or Ebola Virus Disease endemic area
• travel to a Crimean-Congo haemorrhagic fever endemic area and sustained a tick bite, or crushed a tick with their bare hands
• close involvement with animal slaughter in a VHF endemic area.

If any of these additional risk criteria are met, the patient requires further assessment in a hospital setting. An expert advisory group (EAG) should be convened to inform testing and ongoing management, including differential diagnoses, and patient placement. Where transfer to the nearest public hospital is required, it should be via ambulance where officers have been notified of suspected VHF status. Notification should be made to the hospital’s emergency and infectious diseases consultants/infection control regarding the transfer. A patient that has met additional risk criteria should be managed in line with Infection, prevention and control guidelines for Viral Haemorrhagic Fever until VHF diagnosis has been excluded.

Notification of possible VHF cases detected at an international border, and decisions concerning case and contact management, including assessment, transport and isolation will be made by the jurisdictional Chief Human Biosecurity Officer (CHBO) or delegated Human Biosecurity Officer (HBO).² HBOs should alert the CHBO of the situation promptly after arranging transport to hospital for the traveller.

If additional risk criteria are not met, VHF is unlikely, and an alternative diagnosis should be investigated.

Refer to Appendix 1 – Public health risk assessment (PDF 385 kB)

Testing
Requests for VHF testing should be notified to the Chief Health Officer (or delegate CDB Executive Director) via CDB.²

Consider point of care testing for malaria if indicated and minimise other tests to those required for immediate management of the patient, until exclusion of VHF.

Diagnostic information and laboratory aspects for VHF are available from Pathology Queensland.

Ensure early contact with the medical microbiologist on-call for the Public and Environmental Health Reference Laboratory (PEHRL) to obtain advice on specimen collection, and to expediate testing and ensure suitable precautions.

Essential specimens for VHF PCR, isolation and sequencing include serum and tissue samples. Additional sample types should be discussed with the on-call microbiologist at the referring laboratory or at PEHRL.

The PEHRL team will liaise with the National High Security Quarantine Laboratory at VIDRL as required.

Postmortem specimens may include serum, liver, spleen and kidney tissues where possible.²⁵

Restriction and isolation
A case under investigation that has met additional risk criteria as above should be managed in line with Infection, prevention and control guidelines for Viral Haemorrhagic Fever until VHF diagnosis has been excluded.

Cases

Case clearance and counselling
An EAG, including public health and infectious diseases specialists, will advise on the public health clearance of the case, considering the causative virus, symptoms, treatment, and individual patient circumstances.

Until advised, cases should not:

• donate blood, cells, tissue, breast milk, semen or organs
• practice unprotected sex.

Contacts

Contact Tracing
Contact tracing is indicated for probable or confirmed cases but should commence as soon as a risk assessment suggests increased possibility of VHF and testing is indicated.

Definition
A contact is defined as a person who has been exposed to a case or a case’s secretions, excretions or tissues during the case’s period of communicability (from onset of illness until 3 weeks after onset of illness).

For detailed information and advice regarding the management of healthcare workers who have had contact with patients with VHF, refer to the Infection, prevention and control guidelines for Viral Haemorrhagic Fever

Investigation

Contacts should be categorised into casual, low or high level of risk:^2,26

Table 1: Risk assessment and management for contacts

†Other symptoms can include muscle aches and pains, fatigue (extreme  tiredness), headache, sore throat, conjunctivitis (irritated or red eyes), flushing of the skin, diarrhoea and vomiting, internal and external bleeding (e.g. blood in stool or persistent bleeding from mouth or venepuncture sites or bruising).²⁷

Adapted from Viral haemorrhagic fevers – Part of the Communicable Disease Control Manual, Health New Zealand 2024.²⁶

Prophylaxis
Ribavirin postexposure prophylaxis for high risk Lassa fever contacts can be considered in consultation with an infectious diseases physician.⁵

Restriction and isolation
Quarantine is not routinely required for asymptomatic contacts in any risk category, however public health units should conduct a detailed risk assessment and provide specific advice on any restrictions to movement.

Any contact who develops a temperature of >38 °C, or any other symptoms of illness, should be isolated until tests return negative.²⁷

In Queensland, all HCW who return after caring for VHF cases overseas are requested to enter into voluntary home restriction in Brisbane for 21 days from their last contact with a VHF case or their environment. Brisbane is preferred as a location for this voluntary home restriction because it allows proximity to the large metropolitan hospitals.

Counselling
All contacts should be advised of the nature of the infection, its mode of transmission, reasons for public health restrictions, and be provided with appropriate written information.

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References

1.       Communicable Diseases Network Australia. Viral haemorrhagic fever (not elsewhere classified) – Surveillance case definition. Commun Dis Netw Aust [Internet]. 2014 Nov 6; Available from: https://www.health.gov.au/sites/default/files/documents/2022/06/viral-haemorrhagic-fever-not-elsewhere-classified-surveillance-case-definition.pdf

2.       Communicable Diseases Network Australia. Ebola Virus Disease, Guidelines for Public Health Units [Internet]. 2019. Available from: https://www.health.gov.au/resources/publications/ebola-virus-disease-cdna-national-guidelines-for-public-health-units?language=en

3.       U.S. Centers for Disease Control and Prevention. Outbreak History [Internet]. Ebola. 2024 [cited 2024 Jul 16]. Available from: https://www.cdc.gov/ebola/outbreaks/index.html

4.       Rollin PE. Ebola/Marburg Viral Diseases. In: Control of Communicable Diseases Manual [Internet]. American Public Health Association; 2021 [cited 2024 Jun 10]. (Control of Communicable Diseases Manual). Available from: https://ccdm.aphapublications.org/doi/10.2105/CCDM.2745.058

5.       Rollin PE. Arenaviral Hemorrhagic Fevers, Old World. In: Control of Communicable Diseases Manual [Internet]. American Public Health Association; 2015 [cited 2024 Jun 13]. (Control of Communicable Diseases Manual). Available from: https://ccdm.aphapublications.org/doi/10.2105/CCDM.2745.028

6.       Bente DA, Forrester NL, Watts DM, McAuley AJ, Whitehouse CA, Bray M. Crimean-Congo hemorrhagic fever: History, epidemiology, pathogenesis, clinical syndrome and genetic diversity. Antiviral Res. 2013 Oct 1;100(1):159–89.

7.       Hewson R. Understanding Viral Haemorrhagic Fevers: Virus Diversity, Vector Ecology, and Public Health Strategies. Pathogens. 2024 Oct;13(10):909.

8.       Australian Government Department of Health and Aged Care. Biosecurity (Listed Human Diseases) Determination 2016 [Internet]. Australian Government; 2020 [cited 2024 Jun 10]. Available from: https://www.legislation.gov.au/F2016L01027/latest

9.       Australian Government Department of Health and Aged Care. National Health Security Act 2007 [Internet]. Australian Government Department of Health and Aged Care; 2024. Available from: https://www.legislation.gov.au/C2007A00174/latest/text

10.     Flórez-Álvarez L, de Souza EE, Botosso VF, de Oliveira DBL, Ho PL, Taborda CP, et al. Hemorrhagic fever viruses: Pathogenesis, therapeutics, and emerging and re-emerging potential. Front Microbiol. 2022 Oct 25;13:1040093.

11.     Krubiner CB, Schwartz DA. Viral Hemorrhagic Fevers in Pregnant Women and the Vaccine Landscape: Comparisons Between Yellow Fever, Ebola, and Lassa Fever. Curr Trop Med Rep. 2019 Dec 1;6(4):186–96.

12.     U.S. Centers for Disease Control and Prevention. About Crimean-Congo hemorrhagic fever [Internet]. Crimean-Congo Hemorrhagic Fever. 2024 [cited 2024 Jun 10]. Available from: https://www.cdc.gov/crimean-congo-hemorrhagic/about/?CDC_AAref_Val=https://www.cdc.gov/vhf/crimean-congo/transmission/index.html

13.     World Health Organization. Crimean-Congo haemorrhagic fever [Internet]. [cited 2024 Oct 29]. Available from: https://www.who.int/news-room/fact-sheets/detail/crimean-congo-haemorrhagic-fever

14.     World Health Organization. Ebola virus disease [Internet]. 2023 [cited 2024 Jul 17]. Available from: https://www.who.int/news-room/fact-sheets/detail/ebola-virus-disease

15.     U.S. Centers for Disease Control and Prevention. About Lujo Hemorrhagic Fever [Internet]. Lujo Hemorrhagic Fever. 2024 [cited 2025 Jan 10]. Available from: https://www.cdc.gov/lujo-fever/about/index.html

16.     UK Health Security Agency. Lassa fever:origins, reservoirs, transmission and guidelines [Internet]. GOV.UK; 2024. Available from: https://www.gov.uk/guidance/lassa-fever-origins-reservoirs-transmission-and-guidelines

17.     Tsergouli K, Karampatakis T, Haidich AB, Metallidis S, Papa A. Nosocomial infections caused by Crimean–Congo haemorrhagic fever virus. J Hosp Infect. 2020 May 1;105(1):43–52.

18.     Queensland Health, Communicable Diseases Branch. Infection prevention and control for the management of Viral Haemorrhagic Fevers [Internet]. Queensland Health; 2024. Available from: https://www.health.qld.gov.au/__data/assets/pdf_file/0021/1350372/vhf-infection-prevention-guideline.pdf

19.     UK Health Security Agency. Crimean-Congo haemorrhagic fever: origins, reservoirs, transmission and guidelines [Internet]. Guidelines. 2024 [cited 2024 Oct 25]. Available from: https://www.gov.uk/guidance/crimean-congo-haemorrhagic-fever-origins-reservoirs-transmission-and-guidelines

20.     UK Health Security Agency. Ebola: overview, history, origins and transmission [Internet]. Guidelines. [cited 2024 Oct 25]. Available from: https://www.gov.uk/government/publications/ebola-origins-reservoirs-transmission-and-guidelines/ebola-overview-history-origins-and-transmission

21.     Schneider KA, Bonney JHK, Kubio C, Awandare GA, Eichner M. Reconsidering the incubation period of Marburg virus disease. Lancet Infect Dis. 2022 Nov;22(11):1525–6.

22.     UK Health Security Agency. Marburg virus disease: origins, reservoirs, transmission and guidelines [Internet]. Guidelines. 2024 [cited 2024 Oct 25]. Available from: https://www.gov.uk/guidance/marburg-virus-disease-origins-reservoirs-transmission-and-guidelines

23.     Frank MG, Weaver G, Raabe V. Crimean Congo Hemorrhagic Fever Virus for Clinicians—Virology, Pathogenesis, and Pathology - Volume 30, Number 5—May 2024 - Emerging Infectious Diseases journal - CDC. [cited 2024 Jul 17]; Available from: https://wwwnc.cdc.gov/eid/article/30/5/23-1646_article

24.     Chughtai AA, Barnes M, Macintyre CR. Persistence of Ebola virus in various body fluids during convalescence: evidence and implications for disease transmission and control. Epidemiol Infect. 2016 Jun;144(8):1652–60.

25.     Public Health Laboratory Network. Viral haemorrhagic fever – Laboratory case definition [Internet]. 2017. Available from: https://www.health.gov.au/sites/default/files/documents/2022/06/viral-haemorrhagic-fever-laboratory-case-definition.pdf

26.     Health New Zealand. Viral haemorrhagic fevers [Internet]. Viral haemorrhagic fevers, Communicable Disease Control Manual. 2024. Available from: https://www.tewhatuora.govt.nz/for-health-professionals/clinical-guidance/communicable-disease-control-manual/viral-haemorrhagic-fevers#management-of-case

27.     Communicable Diseases Network Australia. Ebola Virus Disease (EVD) CDNA National Guidelines for Public Health Units [Internet]. Australian Government Department of Health and Aged Care; 2019. Available from: https://www.health.gov.au/resources/publications/ebola-virus-disease-cdna-national-guidelines-for-public-health-units?language=en

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Appendices

Download the Patient Risk Assessment Flow Chart (PDF 385 kB)

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