Phylogenetic analysis reveals a new introduction of Yellow Fever virus in São Paulo State, Brazil, 2023.

Yellow Fever (YF) is a viral arbovirosis of Public Health importance. In Brazil, surveillance is focused mainly on detecting epizootic events of Platyrrhini. Herein, we compared the detection and phylogenetic analysis of YF virus in two neotropical primates (NTP), a Callithrix detected in the previous epidemic period (2016-2020), and a Callicebus nigrifons, showing a new introduction of YF in 2023. This paper illustrates the importance of joint actions of laboratory and field teams to ensure quick response to Public Health emergencies, such as the intensification of vaccination of susceptible human populations.

Yellow Fever as Cause of Death of Titi Monkeys (Callicebus Spp.).

From 2016 to 2018, an epidemic wave of yellow fever (YF) occurred in Brazil, affecting a large number of Platyrrhini monkeys. Titi monkeys (Callicebus spp.) were severely affected yet pathological characterizations are lacking. This study characterized epizootic YF in 43 titi monkeys (Callicebus spp.) with respect to the microscopic lesions in liver, kidney, spleen, heart, brain, and lung, as well as the distribution of immunolabeling for YF virus antigen, and the flaviviral load in the liver. Of 43 titi monkeys examined, 18 (42%) were positive for yellow fever virus (YFV) by immunohistochemistry or reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). Affected livers had consistent marked panlobular necrotizing hepatitis, lipidosis, and mild inflammation, with intense immunolabeling for YFV mainly in centrilobular hepatocytes (zone 1; P = .05). In the spleen, consistent findings were variable lymphoid depletion (10/11), lymphoid necrosis (lymphocytolysis; 4/11), and immunolabeling for YFV in histiocytic cells (3/16). The main finding in the kidney was multifocal acute necrosis of tubular epithelium (5/7) that was occasionally associated with intracytoplasmic immunolabeling for YFV (6/15). These data indicate that titi monkeys are susceptible to YFV infection, developing severe hepatic lesions and high viral loads, comparable to humans and Alouatta spp. Thus, Callicebus spp. may be reliable sentinels for YF surveillance.

Yellow fever surveillance challenge: Investigation of a marmoset non-autochthonous case.

Yellow fever (YF) surveillance in Brazil is focused mainly on the detection of epizootic events regarding New World non-human primates (NWNHP). We present a challenging case of a Callitrichidae (Callithrix spp) kept as a domiciliated pet that lived in the urban area of São Paulo municipality and was positive to YF virus by RT-qPCR and immunohistochemistry. After investigation, it was the first occurrence of non-autochthonous YF case of NWNHP described, with probable place of infection in the North shore of São Paulo state. This case illustrates the importance of coordinated laboratorial and field actions, and risks posed by transit of wildlife.

Yellow fever surveillance challenge: Investigation of a marmoset non-autochthonous case

Yellow fever (YF) surveillance in Brazil is focused mainly on the detection of epizootic events regarding New World non-human primates (NWNHP). We present a challenging case of a Callitrichidae (Callithrix spp) kept as a domiciliated pet that lived in the urban area of São Paulo municipality and was positive to YF virus by RT-qPCR and immunohistochemistry. After investigation, it was the first occurrence of non-autochthonous YF case of NWNHP described, with probable place of infection in the North shore of São Paulo state. This case illustrates the importance of coordinated laboratorial and field actions, and risks posed by transit of wildlife.

Diagnóstico de febre amarela em tecidos fixados em formalina e emblocados em parafina de primatas não humanos: a importância do exame histopatológico

Os casos de óbitos ou convalescência de primatas não-humanos (PNH) por febreamarela (epizootias) apontam a circulação do vírus em uma determinada região e podemanteceder a ocorrência dessa doença em humanos. Portanto, o diagnóstico adequado destaenfermidade nos diferentes gêneros de PNH presentes no Brasil é importante para adoçãode medidas estratégicas de controle da FA, como a vacinação. O Centro de Patologiado Instituto Adolfo Lutz (CPA-IAL), laboratório de referência macrorregional, participado Programa de Vigilância de Epizootias em PNH do Ministério da Saúde, por meioda realização de exames histopatológico e imuno-histoquímico para FA. Este trabalhoapresenta a casuística recebida e analisada no CPA-IAL durante o ano de 2017. Foramavaliadas amostras de 2.171 PNH, com resultado de 626 positivas no exame imunohistoquímico do fígado (28,83%). Destas, o estado de preservação foi satisfatório em580 e insatisfatório devido à autólise em 132. Das satisfatórias...

Epizootics of Yellow Fever in non-human primates (NHP) are indicative of viralcirculation of the Yellow Fever virus (YFV) and may predict the occurrence of humancases. Therefore, adequate diagnosis of the disease in the different genera of NHPoccurring in Brazil is important for YF control strategies, such as vaccination. ThePathology Center of the Adolfo Lutz Institute (CPA-IAL), a macro-regional referencelaboratory, participates in the Epizootic Surveillance Program through histopathologicaland immunohistochemical exams for YF. This study presents the caseload received andanalyzed at the CPA-IAL during 2017, with especial emphasis on YF immunopositivityin the liver. Samples from 2,171 NHPs were evaluated in 2017. From these, 626 (28.83%)were positive by immunohistochemistry; 580...