2025-05-22-世界卫生组织-WHO_Rapid_Risk_Assessment_-_Oropouche_virus_disease,_Region_of_the_Americas_v.1_9页_384kb

RAPID RISK ASSESSMENT OF OROPOUCHE VIRUS (OROV)

Summary

• Event: Acute event of potential public health concern involving Oropouche Virus, documented in countries within the Region of the Americas since 1955 (Trinidad and Tobago).
• Risk Level: Moderate regional risk with moderate confidence in available information. Low global risk outside the Americas.
• Clinical Presentation: Symptomatology similar to other arboviral diseases; most cases mild to moderate (self-limiting, recovering in ~7 days), though rare cases of aseptic meningitis occur. No direct human-to-human transmission or fatalities documented. No preventative vaccine or specific antiviral treatment available; supportive care provided.
• Etiology: Caused by a segmented single-stranded RNA virus (Orthobunyavirus). Transmitted primarily by the Culicoides paraensis midge, mosquitoes like Culex quinquefasciatus, and others (Coquillettidia venezuelensis, Aedes serratus).
• Transmission: Vector-borne transmission occurs mainly via the bite of infected mosquitoes/midges, often amplified in forested (sylvatic) environments but also noted in urban/rural settings.
• Outbreaks: Mostly reported in the Amazon Basin region over the last decade. Brazil currently reports significant new cases in multiple states (Amazonas, Acre, Roraima). Colombia, Ecuador, French Guiana, Panama, Peru also have historical or recent detections/incidents.
• Factors Increasing Risk:
  • Climate change (increased rainfall, temperature).
  • Deforestation, agriculture, urbanization, infrastructure development.
  • Human travel, migration.
  • Weak surveillance systems and lack of widespread laboratory testing.
  • Vulnerable populations due to migratory phenomena or weakened health services.
• Actions Taken/Suggested:
  • Review by IHR Committees considered, not declared a PHEIC.
  • Urgent public health response (ERF IMS) deemed not currently required.
  • Immediate support offered to specific country investigations (not listed).
  • Conduct rapid epidemiological analysis and support for grading calls.
  • Sustained: monitoring, support for preparedness, evaluation of support (grading). actions are mainly recommendations for ongoing support (monitoring, continuing support).
• Key Challenges: Inadequate surveillance, weak diagnostic capacity, limited laboratory resources, underestimation of disease burden, lack of preparedness and specific treatments/vaccines.

Implications: This assessment characterizes the ongoing OROV transmission, emphasizing the need for vector control, strengthened surveillance (especially with climate events), and continued monitoring by PAHO/WHO and Member States, particularly under climatic effects increasing vector activity.