Oropouche virus disease: For health professionals
On this page
- Key information
- Transmission
- Clinical manifestations
- Diagnosis
- Management and treatment
- Prevention
- Surveillance
Key information
Oropouche virus disease is a vector-borne zoonotic disease. The Oropouche virus is a segmented single-stranded RNA virus belonging to the family Peribunyaviridae, genus Orthobunyavirus. It's mainly transmitted through the bite of an infected biting midge and less commonly by mosquitoes. The specific species of biting midge and mosquito aren't known to be established in Canada.
Signs and symptoms of Oropouche virus disease are non-specific and can present like many other acute febrile illnesses. Most people have mild symptoms but in rare cases, Oropouche virus disease can cause severe illness.
Current evidence related to Oropouche virus disease in pregnancy is limited, although it suggests the potential for vertical transmission and possible negative outcomes, such as spontaneous abortion and congenital microcephaly. Infants with possible or confirmed prenatal exposure to Oropouche virus should be assessed by an infectious disease specialist and monitored for congenital complications. Pregnant people or people planning to become pregnant are advised to avoid non-essential travel to areas experiencing an Oropouche virus outbreak.
Replication-competent virus has been found in semen and viral RNA has been found in vaginal fluids. Further research is required to determine if sexual transmission can occur. In the interim, a precautionary approach is recommended that could include use of barrier protection when engaging in sexual intercourse if Oropouche virus is confirmed or suspected.
There's no specific treatment or vaccine for Oropouche virus disease. The best way to prevent Oropouche virus disease is to prevent bites from midges and mosquitoes.
For individuals with signs or symptoms similar to those of Oropouche virus disease or other acute febrile illnesses, we encourage health professionals to consider the possibility of infection with other arboviruses.
Transmission
Oropouche virus is primarily transmitted through the bite of infected Culicoides paraensis midges (a very small biting fly also known as a no-see-um). It may also be spread by Culex quinquefasciatus mosquitoes.
Current evidence related to Oropouche virus disease in pregnancy is limited, however there's a potential for vertical transmission and possible negative outcomes, such as spontaneous abortion and congenital microcephaly.
Replication-competent virus has been found in semen and viral RNA has been found in vaginal fluids. Further research is required to determine if sexual transmission can occur.
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Clinical manifestations
The incubation period usually ranges from 3 to 8 days.
Signs and symptoms of Oropouche virus disease are non-specific and may be similar to many other acute febrile illnesses.
Signs and symptoms may appear suddenly and include:
- chills
- fever
- nausea
- diarrhea
- vomiting
- dizziness
- headache
- retro-orbital pain
- maculopapular rash
- arthralgia (joint stiffness)
- myalgia (muscle aches and pains)
- photophobia (sensitivity to light)
There are no reported long-term sequelae following recovery from acute illness.
Oropouche virus can progress to severe disease and may present with hemorrhagic manifestations or neurological involvement.
Hemorrhagic manifestations may include:
- petechiae
- melena (black stool)
- epistaxis (nose bleed)
- gingival bleeding (bleeding of the gums)
- menorrhagia (heavy menstrual bleeding)
Neurological involvement including meningitis and encephalitis, may include:
- nausea
- lethargy
- dizziness
- vomiting
- confusion
- photophobia
- neck stiffness
- diplopia (double vision)
- occipital pain (pain behind the eyes)
- nystagmus (involuntary and rapid eye movements)
Neurological involvement can last for 2 to 4 weeks. In most people, the acute phase typically lasts up to 7 days. Viremia peaks during the acute phase and decreases over the next several days.
In approximately 60% to 70% of cases, the symptoms re-appear after the patient initially recovers. This typically occurs within 2 to 10 days post initial recovery but may occur up to 1 month later.
Risk factors for severe disease aren't well known. People at higher risk of severe outcome may include:
- young children
- older adults
- people with pre-existing health conditions
A pregnant person may pass the Oropouche virus to their unborn baby, with possible negative outcomes such as stillbirth and microcephaly.
Diagnosis
Diagnosis of Oropouche virus disease is confirmed by a laboratory test.
Oropouche virus disease should be considered in individuals:
- with suggestive symptoms and
- who have recently lived in or travelled to an area where Oropouche virus is common (2 weeks before the initial onset of symptoms)
For individuals with signs or symptoms similar to those of Oropouche virus disease or other acute febrile illnesses, we encourage health professionals to consider the possibility of infection with other arboviruses, including:
Laboratory testing
There are 2 methods to test for Oropouche virus:
- polymerase chain reaction (PCR)
- serology
The National Microbiology Laboratory can test for Oropouche virus and will accept samples that:
- were collected early after symptom onset (within 7 to 10 days) and
- are PCR negative for dengue, chikungunya and Zika viruses
Testing will only be done for people who have travelled to an area where Oropouche virus is known or suspected to be spreading. Priority will be given to people who have travelled to an area with an outbreak. Provincial and territorial public health authorities may request exceptions. Contact your local public health laboratory for testing guidance.
Management and treatment
There's no specific treatment for Oropouche virus disease.
Medical care aims to control symptoms and help with recovery, and may include:
- taking acetaminophen (such as Tylenol) to control fever
- adequate oral hydration
Nonsteroidal anti-inflammatory medications and aspirin-based products should be avoided because of the increased risk of bleeding.
Individuals with severe disease may require hospitalization and if needed, intensive care for hemodynamic and respiratory support.
Given the limited evidence on pregnancy, pregnant people should be monitored by health professionals with expertise in obstetrics and infectious diseases. Infants born to a person with a confirmed diagnosis of Oropouche virus disease should be clinically evaluated by an infectious disease specialist and tested for Oropouche virus.
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Prevention
There's no vaccine to prevent Oropouche virus disease.
Oropouche virus disease can be prevented by using:
- personal protection (insect repellent, loose clothing, mosquito nets)
- insect control (removing stagnant water, insecticides)
Until there's evidence that Oropouche virus can be transmitted sexually, a precautionary approach is recommended if Oropouche virus is confirmed or suspected. This could include use of barrier protection when engaging in sexual activities.
Learn more:
- Oropouche virus disease: Prevention and risk
- Insect bite and pest prevention
- Committee to Advise on Tropical Medicine and Travel statement: Personal protective measures to prevent arthropod bites (PDF)
Surveillance
The Public Health Agency of Canada (PHAC), in collaboration with provincial and territorial public health authorities, monitors Oropouche virus disease. PHAC works with national and international partners, including the Pan American Health Organization, to monitor cases, share information and conduct risk assessments.
Health professionals should report cases to PHAC by following local, provincial or territorial processes.
PHAC reports positive samples and confirmed cases to the Pan American Health Organization and the World Health Organization through the established channels of the International Health Regulations.
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