São Paulo, Brazil, August 21, 2025 – The Pan American Health Organization (PAHO) convened in São Paulo regional experts in surveillance, virology, clinical practice, genetics, and congenital malformations from Argentina, Brazil, Chile, Uruguay, Cuba, Costa Rica, and Nicaragua, together with technical teams from BIREME, the PAHO Country Office in Brazil, and the PAHO/WHO Headquarters in Washington, D.C. (PHE, HSS, and CDE). The interprogrammatic meeting, held from August 20 to 21, 2025, aimed primarily at advancing the definition of guidelines for integrated surveillance of vertical transmission of the Oropouche virus (OROV) and reviewing the available evidence on associated congenital defects.
This activity is part of PAHO’s efforts to respond to the regional Oropouche emergency, which recorded, between epidemiological weeks 1 and 30 of 2025, a total of 12,786 confirmed cases in eleven countries of the Americas. In 2024, 16,239 confirmed cases were reported, including four deaths, confirming the sustained spread of this arbovirus in the Region.
Key outcomes of the meeting
Among the main outcomes of the meeting, experts discussed and reached consensus on a case definition for vertical transmission of OROV, considering clinical, laboratory, and imaging criteria. The inclusion criteria for identifying and monitoring pregnant women with Oropouche infection and newborns with signs consistent with congenital syndrome were also reviewed. In addition, guidelines were proposed for the collection of key biological samples, such as placenta, umbilical cord, neonatal serum, and fetal tissues. During the meeting, experts also presented national experiences in monitoring at-risk populations and following up on exposed newborns, and analyzed the challenges of linking Oropouche surveillance with that of other arboviruses and congenital malformations.
Continuity of regional efforts
This meeting built on the first regional activity held in February 2025, in which countries and experts defined research priorities on OROV. In São Paulo, progress was made in developing technical guidelines for surveillance of vertical transmission and in planning cohort studies that will allow medium-term assessment of fetal and neurological complications.
Next steps
The participating teams agreed to strengthen technical cooperation in arboviruses and to move forward with the implementation of standardized protocols for the early identification of suspected cases, the monitoring of pregnant women and newborns, and the integration of laboratory networks in the Region. Through these actions, PAHO and its Member States reaffirm their commitment to addressing the emerging threat of the Oropouche virus in a coordinated manner and to protecting the most vulnerable populations.
