Histopathologic Patterns and Susceptibility of Neotropical Primates Naturally Infected With Yellow Fever Virus

Abstract

Yellow fever is an important zoonotic viral disease that can be fatal for both human and nonhuman primates. We evaluated histopathologic changes in free-ranging neotropical primates naturally infected with yellow fever virus (YFV) compared with uninfected cohorts. The most frequent lesions in primates infected with YFV were hepatic changes characterized by midzonal necrosis with lipidosis and mild inflammation including lymphocytes, macrophages, plasma cells, and infrequently neutrophils. Importantly, severe necrotizing hepatic lesions were often observed in <i>Alouatta</i> sp. (howler monkeys), whereas <i>Callithrix</i> sp. (common marmosets) had nearly no hepatic changes. Moderate to severe hepatic necrosis was present in 21/23 (91%) of the YFV-positive <i>Alouatta</i> sp. compared with 10/29 (34%) of the YFV-positive <i>Callithrix</i> sp. (<i>P</i> < .0001; odds ratio = 20). Similarly, hepatitis was more intense in <i>Alouatta</i> sp. compared with <i>Callithrix</i> sp. Furthermore, the frequency of YFV infection was significantly higher in <i>Alouatta</i> sp. compared with <i>Callithrix</i> sp. or <i>Sapajus</i> sp. (capuchin monkeys). Therefore, these data support the notion that <i>Alouatta</i> sp. is highly susceptible to infection and YFV-induced lesions, whereas <i>Callithrix</i> sp. is susceptible to infection but has a lower frequency of YFV-induced lesions.