9.15. Oropouche Virus

Updated 15 October 2025

Standard Operating Procedure for the Surveillance of Oropouche Virus 

Effective Date: [Date to be Determined]

Version: 1.0

Prepared by: Dr. Maurice Frank, International PAHO Consultant, PAHO Barbados and ECC

Approved by: [Name/Department]

  

Status 

Definition 

A

Tested / reflects current policy and updates

B

Possible gaps / may not reflect latest policies and updates / users need to apply due diligence

C

Outline / being updated / users should cross reference other materials (job aids, training resources)

D

Draft / consider as being under development 

E

Work in progress / template created 

 

1. Introduction

  • Purpose:
     The purpose of this standard operating procedure (SOP) is to outline the procedures for the surveillance of human infections with Oropouche virus in a comprehensive step by step manner to ensure timely detection, reporting, and response to outbreaks in human populations. It defines the roles and responsibilities of all involved actors to ensure coordinated, effective multisectoral efforts.
  • Scope:
     This SOP applies to all animal health, vector management, public health entities, healthcare providers, laboratories, and other stakeholders involved in viral zoonotic disease/arbovirus surveillance.
  • Definitions:
    • Oropouche Virus: OROV is transmitted in a sylvatic cycle that probably involves primates, sloths, and birds as reservoirs. The vector of this cycle is unknown, although there is evidence of the involvement of mosquitoes such as Aedes serratus and Coquillettidia venezuelensis. OROV can also be transmitted in an urban cycle, in which the human is the amplifier host. The main vector of this cycle is the biting midge Culicoides paraensis. The Culex quinquefasciatus mosquito can also be a vector.
    • Surveillance: Systematic collection, analysis, and interpretation of health data.

  • Legal Framework:
     Reference to national, regional and international health regulations guiding the prevention, surveillance, treatment and control of influenza viruses especially of novel antigenic drift and shift events, and/or spillover events. 

     

2. Key Actors Involved and Their Roles

2.1 Epidemiology Unit 
  • Role:
     This is the central body responsible for overseeing the surveillance process in human populations.
  • Responsibilities:
    • Develop and update national guidelines and protocols for influenza surveillance in human populations.
    • Coordinate with the animal health unit, district health authorities, and laboratories on surveillance, detection, treatment and care of zoonotic respiratory viruses.
    • Provide training and resources to healthcare providers and other stakeholders.
    • Analyse surveillance data and disseminate findings to various target audiences.
    • Weekly reporting of syndromes of Fever and Respiratory and suspicion of zoonotic transmission based on history to regional and international bodies like PAHO, PAHO PANAFTOSA, and CARPHA.
    • Monitor national sentinel sites for the quality of nasopharyngeal, oropharyngeal and bronchioalveolar lavage (BAL) submissions to national and regional Flu Laboratories for testing.
    • The timely completion and submission of case/outbreak reporting templates.
    • To monitor and maintain national stockpiles of antiviral drugs and personal protective equipment (PPE). 
2.2 Veterinary Public Health/ Animal Health Unit (Ministry of Health/ Ministry of Agriculture) (in collaboration with Environmental Health*) 
  • Role:
    The Veterinary Public Health/Animal Health Unit reports directly to the Epidemiology Unit, PAHO PANAFTOSA, Caribbean Animal Health and Food Safety Agency (CAHFSA), and the Caribbean Animal Health Network – Avian Diseases Working Group (CaribVET) and is responsible for the complete reporting, and investigation of domesticated and wild animals demonstrating typical/atypical clinical signs of avian influenza.
  • Responsibilities:
    • Utilise the national, regional and international avian influenza guidelines for domestic and wild animals, especially poultry and wild birds*.
    • Implement, maintain, and enhance when required, routine active and passive surveillance systems for avian influenza/avian diseases in poultry and wild birds*.
    • Collaborate with national/regional wildlife ecologists and/or biologists to conduct event-based surveillance for avian influenza in wild birds – waterfowl*.
    • Collaborate with climatologists and wildlife ecologists to review changes in avian migration patterns*.
    • Develop and institute national contingency plans for avian influenza*.
    • Conduct routine education campaigns with farmers, birders, and field naturalists, on reporting channels for bird die-offs (domestic and wild birds) *.
    • Conduct routine sample collection, storage, and submission in field-settings in accordance with internationally established guidelines for the submission of samples for avian virus detection, to accredited veterinary diagnostic laboratories.
    • Submit relevant surveillance data to the Epidemiology Unit.
    • Coordinate with the designated laboratories for results and conduct timely and effective dissemination to relevant personnel and the national population.
    • Inform animal owners/ farmers of test results and follow-up with the Epidemiology Unit and/or relevant Health Units on appropriate biological containment and quarantine measures.
    • Educate poultry farmers on biosecurity measures and reporting channels.
    • Report occurrences of dead birds at commercial and backyard farms and coastal and inland environments and monitor persons exposed to the infected/dead birds for 10-14 days (report directly to the Epidemiology Unit). 
2.3 Health Units (HU) and Healthcare Providers (HCPs)
  • Role:
     The HU is the frontline body responsible for detecting and reporting suspected/probable zoonotic avian influenza cases within the human population.
  • Responsibilities:
    • Conduct weekly reporting of Fever with Respiratory symptoms to Epidemiology Unit.
    • Conduct timely reporting to the Epidemiology Unit of persons suspected of having high-risk exposure to zoonotic avian influenza (poultry farm workers, veterinarians, biologists, travel history).
    • Complete and submit the case investigation form to the Epidemiology Unit.
    • Aid the Epidemiology Unit on community education on avian influenza/ respiratory virus prevention and control.
    • Conduct routine specimen collection for respiratory virus surveillance and report results to patients.
    • Review stockpiles of antivirals and post-exposure prophylaxis. 
2.4 Expanded Program on Immunization 
  • Role:
  • The Expanded Program on Immunization are responsible for monitoring the sustainable procurement and distribution of rabies immune globulin (RIG) and vaccines to public sentinel treatment and care sites.
  • Responsibilities:
    • Identify and address stockouts of rabies immune globulin (RIG) and vaccines.
    • Guide healthcare providers on appropriate storage and administration of vaccines.
    • Coordinate rabies vaccination efforts with high-risk individuals (veterinarians, laboratory technologists, abattoir staff). 
2.5 Laboratories
  • Role:
     Laboratories play a crucial role in the confirmation of rabies cases.
  • Responsibilities:
    • Provide instructions for sample collection and packaging in accordance with applicable guidelines.
    • Receive samples and laboratory form; inform the relevant unit about rejection of sample as necessary.
    • Conduct diagnostic testing for rabies.
    • Report laboratory results to healthcare providers/ Epidemiology Unit (external laboratories) according to established reporting channels.
    • Maintain quality controls in testing procedures.
    • Share data with the Epidemiology Unit/ Veterinary Public Health Department/ Animal Health Unit and collaborate on epidemiological studies.
    • Coordinate training on specimen collection, storage, and transportation. 
2.6 Pathology Unit (Human and Animal)
  • The Pathology Departments are responsible for conducting post-mortem in humans/ necropsies in animals to examine for gross lesions, and conduct specimen collection for histopathology and diagnostics. 
2.7 Surveillance at Point of Entry
  • The Veterinary Officer/ Immigration Officer is responsible for reviewing animal health records, including immunization history and results from accredited laboratories, prior to allowing animals entry into the country. 
3. Surveillance Procedures

Surveillance procedures for zoonotic avian influenza should be integrated into existing/proposed integrated respiratory virus surveillance strategies and outbreak preparedness plans. 

Step 1: Case Detection – Healthcare Providers / Laboratory Personnel

1. Immediate Reporting:  Report all suspected/probable cases to the Epidemiology Unit immediately for follow up based on exposure risk (farm workers, veterinarians, etcetera) and/or travel history (countries with spillover events) and clinical signs. 

Suspected zoonotic avian influenza A(H5) in humans case definition

A person presenting with unexplained acute respiratory illness with fever (> 38 °C) or cough, shortness of breath or difficulty breathing or conjunctivitis. 

AND 

One or more of the following exposures in the 14 days prior to symptom onset: 

  • Close contact (within 1 metre) with a person (for example, caring for, speaking with or touching) who is a suspected or confirmed avian influenza A(H5) case. 
  • Exposures in an area where avian influenza A(H5) virus infections in animals or humans have been suspected or confirmed, such as: 
    • close contact (within 1 metre) with live, sick or dead infected animals or animal products, or consumption or handling of raw uncooked meat, unpasteurized milk or other raw animal meat or products; 
    • direct exposure to surfaces that could be contaminated with infected animal products or with water contaminated with such products (such as wastewater from a live bird market or slaughtering facility); or
    • visiting or working at a live animal market, farm, zoo or other setting with infected animals. 
  • Handling samples (animal or human) suspected of containing avian influenza A(H5) virus in a laboratory or other setting.

 

Confirmed zoonotic avian influenza A(H5) in humans case definition 

1. A person with a laboratory-confirmed infection with an avian influenza A(H5) virus. 

A laboratory-confirmed infection is considered if it has been confirmed by positive results from polymerase chain reaction (PCR), virus isolation, or serological testing of paired acute and convalescent serum. 

Serologic testing of paired acute and convalescent serum specimens: 

  • Serological confirmation of an A(H5) case requires paired sera collection (one acute, one convalescent specimen), with a ≥ 4-fold rise in neutralizing antibody titres (or equivalent) to an influenza A(H5) virus2 that is antigenically similar to the virus the person was exposed to, with a convalescent neutralizing titre ≥ 1:40. Acute serum should be collected within 7 days of symptom onset; convalescent serum should be collected ≥ 21 days (ideally 21–28 days) after symptom onset. 

2. Serologic testing of a single convalescent serum specimen, when the following are met:

  • The criteria for seropositivity of an A(H5) infection using a single convalescent serum specimen, collected at ≥ 21 days after symptom onset or exposure includes a neutralizing antibody titre ≥ 1:40 to an influenza A(H5) virus; and 
  • A positive result using a different serological assay such as a hemagglutination inhibition (HI) antibody titre ≥ 1:40, or an influenza A(H5)-specific positive result from another immunological assay such as an enzyme-linked immunosorbent assay (ELISA), a multiplex binding antibody assay, or similar binding antibody assay; and 
  • In all assays mentioned above, sera are tested against an influenza A(H5) virus(es)4 or antigen(s) antigenically similar to the virus the person was exposed to; and
  • The person has an epidemiological link to a laboratory-confirmed human case.

 

Step 2: Laboratory Testing 

According to the WHO 

All individuals meeting the suspected surveillance case definition or other locally adapted case definitions for other objectives should be tested according to local protocols. 

The types of samples to be collected for the diagnosis of viral infections of the upper and lower respiratory tract are described in the WHO Manual for the laboratory diagnosis and virological surveillance of influenza. This manual can be found at this link >> https://www.who.int/publications/i/item/manual-for-the-laboratory-diagnosis-and-virological-surveillance-of-influenza 

In cases presenting with conjunctivitis, conjunctival specimens should be collected. 

Molecular detection of influenza viruses can be sourced through coordination with PAHO Barbados and ECC and the CARPHA Medical and Microbiology Laboratory (CMML) at the Caribbean Public Health Agency. 

All influenza A positive specimens that cannot be subtyped should be sent immediately to a designated reference laboratory if originally tested elsewhere, and from the reference laboratory to a WHO Collaborating Centre of GISRS in the Region of the Americas. 

Virus isolation from specimens suspected or confirmed to contain avian influenza A(H5) virus is not recommended, unless it is performed at a WHO influenza Collaborating Centre or a WHO H5 Reference Laboratory of GISRS, due to the biosafety requirements. Serological testing should also be performed or directly supported by or performed in collaboration with one of these named laboratories. See the updated list below. 

WHO H5 Reference Laboratories -An updated list can be found at this link >> https://d.docs.live.net/8bad14f2cdd14a90/Desktop/influenza%20A/H5%20or%20A/H5N1. 

Contact the designated PAHO IHR Focal Point for support of serology testing for A(H5) and other help to confirm a human infection with an avian influenza A(H5) virus. 

Testing of asymptomatic exposed individuals could also be considered on a case-by-case basis, depending on available resources and based on an exposure risk assessment and testing objectives (for example, as part of an outbreak investigation or special study to assess asymptomatic transmission). In such a situation, the testing of respiratory samples for viable and replicating viruses needs to be paired with serological testing of acute and convalescent serum samples. 

See here for the zoonotic avian influenza H5 exposure risk assessment  >> https://www.who.int/teams/global-influenza-programme/avian-influenza/monthly-risk-assessment-summary

Animal Infections 

Updated WOAH Diagnostic Criteria for birds and mammals can be found at this link >> https://www.woah.org/en/disease/avian-influenza/.  

 

Step 3 : Investigation of Confirmed Cases of Zoonotic Avian Influenza (H5) and Monitoring of Exposed Individuals 

Epidemiological investigation requires a national multi-sectoral one health approach and collaboration with external experts from FAO, WOAH, PAHO/PANAFTOSA and PAHO/WHO. 

  • All confirmed human cases of influenza A(H5) infection should be further investigated and closely monitored, and human and animal contacts also monitored to detect and rapidly interrupt potential virus transmission and to better understand exposure risks. 
  • More detailed guidance can be found in the WHO Protocol to investigate non-seasonal influenza and other emerging acute respiratory diseases found at this link >> https://www.who.int/publications/i/item/WHO-WHE-IHM-GIP-2018.2

The specific public health actions that should be implemented immediately include: 

  • testing for cases of human infection with animal influenza A viruses using appropriate investigation and laboratory protocols; 
  • assessing exposure to animals and travel history of confirmed cases; 
  • identification and monitoring of household and other close contacts of a confirmed case (including health care personnel) and active searching for other cases; and 
  • early detection of any unusual respiratory disease events that could signal person-to-person transmission of the virus. 

The specific animal health actions that should be implemented immediately include: 

  • assessing the role of local domestic/wild animals as sources of exposure
  • understanding patterns of illnesses or death in local domestic/wild animals and 
  • determining whether animal influenza viruses are circulating in local domestic/wild animals so that appropriate control measures can be implemented to reduce the risk of continued human exposure.

Implementation of Ongoing Surveillance in Human Populations 

Once a case is confirmed and local transmission established, the Member State should have in place an approach for assessing and monitoring the health of individuals at risk of potential exposure to influenza A(H5) viruses. This may include individuals who work in the poultry or other livestock industry or zoos, visit animal farms or premises in the course of their work, transport or sell live poultry or other animals or carcasses, slaughter or are involved in culling/depopulating/disposing of poultry or other animals or in the decontamination of contaminated premises. Additionally, individuals may have non-occupational potential exposure to A(H5) viruses while interacting with infected or potentially infected animals (persons residing close to wetlands and coastal zones with migratory waterfowls). 

Implementation of Ongoing Surveillance in Domestic Poultry/ Domestic Animals/Wildlife Populations

Based on laboratory confirmation and/or morbidity and mortality reports in flocks/herds and/or necropsy results, incident- and event-based surveillance will need to be implemented in collaboration with CAHFSA, FAO and WOAH (and other national/regional named institutions). 

Step 4: Data Management and Dissemination 
  • Data should be cleaned and analysed between both human and animal health departments. 
  • Data should be disseminated on a shared, secured platform to GISR, PAHO/WHO, WHO IHR (2005), CAHFSA, CARPHA, FAO, WOAH, CaribVET, by the IHR focal point and the Chief Veterinary Officer/ WOAH focal point for Avian Influenza. 
  • Preparation of a case report should be done on the evolution of the epidemiological situation of the disease, utilising information from both human and animal health sectors. 
  • Dissemination of an immediate press release to the local and regional media should be conducted, upon confirmation of a positive diagnosis. 
  • Targeted risk communication and community engagement (RCCE) should be implemented in coordination with local poultry farmers, wildlife ecologists, and relevant animal and human health sectors. 
  • Timely updates and training to human, animal, and environmental health workers, and persons with increased exposure for transmission. 

 

4. Treat clients according to international guidelines 

4.1 Data Management and Dissemination 

  • Data should be cleaned and analysed between both human and animal health departments. 
  • Data should be disseminated on a shared, secured platform. 
  • Preparation of a case report should be done on the evolution of the epidemiological situation of the disease. 
  • Dissemination of an immediate press release to the local and regional media should be conducted, upon confirmation of a positive rabies diagnosis. 
  • Complete reports must be completed and submitted entailing both human and animal health information/ travel history, to the relevant human and animal health units at the regional and international levels.