Amaro N. Duarte-Neto, Katia C. Dantas, Suzette C. Ferreira, Fernando Giugni, Marielton P. Cunha, Shahab Zaki Pour, Felipe L Ledesma, Yeh-Li Ho, Ana C.S. Nastri, Cinthya S.C. Borges, Fernanda A. Rodrigues, Ceila M.S. Malaque, Jaques Sztajnbok, Thaís Mauad, Luiz F.F. Silva, Paulo HN Saldiva, Marisa Dolhnikoff
We investigated respiratory tract pathology in 73 fatal YF cases during the 2017-2019 epidemic in São Paulo, Brazil.
Yellow fever (YF) mainly causes severe hepatitis; data on pulmonary pathology remain limited. We investigated respiratory tract pathology in 73 fatal YF cases during the 2017-2019 epidemic in São Paulo, Brazil. All patients died from YF-related fulminant hepatitis. Autopsies revealed frequent tracheitis (91%), pulmonary edema and hemorrhage (100%), diffuse alveolar damage (84%), secondary pneumonia (84%), and bronchoaspiration (60%). Microabscesses, thrombi, and hemophagocytosis were also observed. In 5 cases of vaccine-associated viscerotropic disease, hemorrhage and diffuse alveolar damage were prominent. We detected antigens of YF virus in all cases and viral RNA in 94%. Molecular analysis identified bacterial and fungal pathogens in pneumonia, including gram-negative bacilli, Candida spp., and Aspergillus spp. Electron microscopy did not reveal viral particles in 3 examined cases. Our findings underscore the respiratory tract involvement in severe YF and could help guide diagnosis, intensive care, and public health preparedness in future outbreaks.