Washington DC, 9 July 2024 (PAHO)- Arthropod-borne viruses (arboviruses) represent a growing threat to global public health, with a notable increase in their geographic spread and incidence in the last decade. Among the best known arboviruses in the Americas are dengue, Zika and chikungunya, all transmitted mainly by the Aedes aegypti mosquito. However, other arboviruses such as Oropouche virus (OROV) and Mayaro virus (MAYV) are gaining attention due to their re-emergence potential.
Since its initial detection in 1955 in Trinidad and Tobago, OROV has caused sporadic outbreaks in several countries in the Americas, including Brazil, Ecuador, French Guiana, Panama, Peru, and Trinidad and Tobago. In late 2023 and in the midst of surveillance for a major dengue outbreak, a significant increase in Oropouche fever cases was observed, especially in the Amazon region of Brazil. According to the latest report of the Brazilian Ministry of Health, more than 6,900 cases have been confirmed in 2024, with autochthonous transmission detected in at least nine states outside the Amazon. On the other hand, in Cuba, cases have been detected in 13 of the 15 provinces, for the first time in the country, and in an ecological context very different from that of the Amazon region.
In response to this situation, the Pan American Health Organization (PAHO), through its Infectious Hazards Management Unit of the Emergency Department (IHM/PHE), and the collaboration of the Arbovirus Program of the Department of Communicable Diseases and Enviromental Determinants of Health (VT/CDE), has carried out various activities and workshops to improve surveillance and response to these viruses. Of particular note was the five-day International Workshop on Molecular Surveillance of Emerging and Re-emerging Arboviruses held in Manaus, capital of the state of Amazonas in Brazil. This event brought together health experts and researchers from Bolivia, Ecuador, Guyana, Paraguay, Peru, Suriname, Venezuela and Brazil to strengthen regional capacities in the collection of viral genetic material, molecular diagnostics, entomo-virological surveillance and epidemiological data analysis. During the workshop, participants were able to analyze 42 complete OROV genomes, underscoring the importance of these initiatives in the context of the current epidemiological scenario in the region.
Since the increase in the number of cases in the Amazon region, PAHO has provided technical support to countries in the region to improve their capacity to detect and characterize Oropouche and Mayaro viruses in a timely manner, strengthening regional defenses against these emerging threats. Reagents have been distributed for the simultaneous molecular detection of OROV and MAYV, a protocol developed by the Instituto Leônidas & Maria Deane (ILMD/Fiocruz Amazônia), and 23 countries currently have the necessary material for early detection of the virus. Reagents needed for the sequencing of the complete genome of the Oropouche virus have also been distributed, in addition to providing technical support for the analysis of the sequences obtained, in collaboration with ILMD-Fiocruz Amazônia.
The activities developed by the team of experts of the Infectious Threats Management Unit with theoretical and practical training have provided the countries with the necessary knowledge to effectively detect and monitor emerging and re-emerging viruses. In addition, the recently published PAHO Guidelines for the Detection and Surveillance of Emerging Arboviruses in the Context of the Circulation of Other Arboviruses have been shared and discussed.
This initiative reinforces the commitment of the Americas in the fight against emerging and re-emerging arboviruses, ensuring a coordinated and effective response to future public health threats.
