Yellow fever in South America – A plea for action and call for prevention also in travelers from SLAMVI, ESGITM, EVASG, ALEIMC, GEPI-SEIMC, SEMEVI, and CMTZMV-ACIN
Alfonso J. Rodríguez‐Morales, Abdulaziz Alhazmi, Abraham Katime, Ahneez Abdul Hameed, Alejandra Morales, Alejandro Lepetic, Alejandro Rísquez, Alex Julián Forero-Delgadillo, Alexis Holguín, Álvaro A. Faccini‐Martínez, Amanda Guerrero, Ana Freitas Ribeiro, Asma Al Balushi, Ayşegül Taylan Özkan, Balram Rathish, Baruch Diaz, Beatriz Elena Porras-Pedroza, Bhanasut Hunsajarupan, Botond Lakatos, Carlos Álvarez, Carlos Neftali Torres-Martinez, Caroline Rönnberg, Cecilia Perret, Christian Wejse, Aayush Adhikari, Corneliu Petru Popescu, Aula Abbara, Cristián Biscayart, D. Katterine Bonilla‐Aldana, Daniele Fasan, Danna Calderon, David de Luna, David A. Forero-Peña, Diana Isabela Costescu-Strachinaru, Diogo Mendes Pedro, Edward J M Monk, Eirini Iliaki, Emanuele Pontali, Emmanuel O. Ngbede, Ferenc Balázs Farkas, Marta Sanz, Florencia Escarrá, Francesca Mariotti, Francesca Norman, Francesco Di Gennaro, Francisco Javier Membrillo de Novales, Germán Arrieta, Giacomo Guido, A. Fuster, Gustavo A. Grandez-Castillo, Hakan Leblebicioğlu, Hanna K de Jong, Hernán Vargas, Jung‐Ah Kim, Jaime A. Cardona‐Ospina, Jaime R. Torres, Jara Llenas‐García, Isabell Wagenhäuser, José A. Oteo, J. Braun, Juan Carlos Arias, Juan P. Hernández, Julián Ruíz Sáenz, Justin Onyebuchi Nwofe, Justyna Kowalska, Kate Jackson, Kübra Aykaç, Leonardo Francesco Rezzonico, Luis Felipe Reyes, Luisa Frallonardo, Manuel Krone, Marcela Fuquen Malagón, M Sempere, Marco Tulio Luque, Maria P. Carlos, Maria Del Mar Faraco Oñorbe, M Moreno, Marinella Lauriola, Mario Masana, Marisa Fernández, Marlén Martínez‐Gutierrez, Marta Díaz‐Menéndez, Miguel J. Martínez, Miguel M. Cabada, Miguel Morante‐Ruiz, Miriam J. Álvarez-Martínez, Nancy Sandoval-Paiz, Nuria Chávez, Oana Joean, Octavio Arce, Oliver Koch, Olivier Épaulard, Osman Sezer Cırıt, Özlem Türkmen Recen, Pasesa Quispe, Patricia Lourdes Guillot Passerini, Petar Velikov, Miguel Hueda-Zavaleta, Πέτρος Ιωάννου, Poleta Luga
Abstract
The origin of yellow fever (YF) is believed to be in Africa, with the disease arriving in the Caribbean and Brazil on slave ships during the 1500s. Then, it spread from the Caribbean to the United States of America (USA), reaching the cities of New Orleans and Philadelphia. It was identified on European soil, arriving via conquistador ships and causing major outbreaks in the French port city of Marseille. Since then, the YF virus has easily adapted to naïve vectors and reservoirs in the tropical Americas, where it is endemic [[1], [2], [3], [4]], and intermittently epidemic (https://www.cdc.gov/yellow-book/hcp/travel-associated-infections-diseases/yellow-fever.html). YF, caused by the YF virus (YFV) (Flaviviridae family) (Orthoflavivirus flavi) (ICTV 2022/2024) (http://bit.ly/4kTkS9z) [5], a mosquito-borne viral disease and one of the most critical hemorrhagic fevers endemic to tropical and subtropical regions of Africa and South America, continues to pose significant challenges to public health, particularly in low and middle-income countries of the latter [1,6]. Globally, about 1.54 billion individuals live in regions conducive to YF transmission [7]. In recent years, South America has experienced a resurgence in YFV and geographical expansion of transmission in some countries, affecting both human and non-human primate (NHP) populations [8,9]. More than 300 cases of YF have been reported in six South American countries during the outbreaks initiated in 2024 and ongoing in 2025, representing up to July 6 2025 a fourfold increase compared to the cases reported in 2024 (61 in 2024 and 255 in half of 2025) (https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON570), with more than 40% resulting in a fatal outcome (Table 1). Such a staggering case fatality rate, in a vaccine-preventable disease, not only highlights the urgency to improve coverage rates and traveler awareness but also underscores YF's standing as one of the deadliest vaccine-preventable viral infections.