The obscurance of the greatest sylvatic yellow fever epidemic and the cooperation of the Pan American Health Organization during the COVID-19 pandemic

INTRODUCTION: Since 2016, Brazil has been in the midst of its largest sylvatic yellow fever epidemic ever, found predominantly outside the Amazon region. Cases originating from Brazil have been reported in France, the Netherlands, Romania, Switzerland, Argentina, and Chile. The epidemic began in the Central-West region of Brazil in 2014, spreading into the Southern region, with significant non-human primate transmission continuing towards Paraguay and Argentina. METHODS: This report is an integrative review of Pan American Health Organization cooperation during a sylvatic yellow fever epidemic. RESULTS: The Pan American Health Organization has played a central role in handling the yellow fever emergency, collaborating with the Ministry of Health and various research groups in supporting interventions of different response areas. The Pan American Health Organization's technical cooperation included: training and workshops to exchange experiences, carrying out technical cooperation in patient management and epidemiological, entomological, laboratory, and epizootic surveillance, organizing the assistance network, and acquiring strategic inputs. The Pan American Health Organization’s technical cooperation supported the Ministry of Health’s decision to adopt a single-dose vaccine and use fractional doses to support the vaccination needs of more than 39,000,000 people. The coronavirus disease 2019 pandemic contributed to the failure of reaching the yellow fever vaccination goals and made it difficult to integrate the yellow fever vaccine into recommended areas. CONCLUSIONS: Given the ongoing coronavirus disease 2019 pandemic, it is necessary to strengthen measures for the surveillance, prevention, and control of yellow fever with multilateral cooperation between countries.