Non-human primates contribute to the spread of yellow fever virus (YFV) and the establishment of transmission cycles in endemic areas, such as Brazil. This study aims to investigate virological, histopathological and immunohistochemical findings in livers of squirrel monkeys (Saimiri spp.) infected with the YFV. Viremia occurred 1–30 days post infection (dpi) and the virus showed a predilection for the middle zone (Z2). The livers were jaundiced with subcapsular and hemorrhagic multifocal petechiae. Apoptosis, lytic and coagulative necrosis, steatosis and cellular edema were also observed. The immune response was characterized by the expression of S100, CD11b, CD57, CD4 and CD20; endothelial markers; stress and cell death; pro and anti-inflammatory cytokines, as well as Treg (IL-35) and IL-17 throughout the experimental period. Lesions during the severe phase of the disease were associated with excessive production of apoptotic pro-inflammatory cytokines, such as IFN-γ and TNF-α, released by inflammatory response cells (CD4+ and CD8+ T lymphocytes) and associated with high expression of molecules of adhesion in the inflammatory foci observed in Z2. Immunostaining of the local endothelium in vascular cells and the bile duct was intense, suggesting a fundamental role in liver damage and in the pathogenesis of the disease.

Herpesviruses are significant pathogens of ruminants. In water buffaloes (Bubalus bubalis), however, herpesviruses have not been thoroughly studied. Although bubaline alphaherpesvirus 1 (BuAHV1) and bovine alphaherpesvirus 1 (BoAHV1) have already been recovered from water buffaloes, to date, no reports on the occurrence of bovine alphaherpesvirus 5 (BoAHV5) in these animals have been published. Therefore, the aim of this study was to search for BuAHV1, BoAHV1, and BoAHV5 in palatine tonsils of apparently healthy water buffaloes from the Pará state, Northern Brazil. Tissue samples of tonsils (n = 293) were screened by a nested PCR (nPCR) targeting a region of UL44 (gC coding gene), followed by sequencing, to detect and differentiate between the viral types. Viral genome segments were detected in 18 out of 293 (6.1%) of the palatine tonsil samples. Two animals carried genomes of BoAHV1 only, eleven animals carried BoAHV5 genomes only, and four animals carried BuAHV1 only. Another animal had both BoAHV1 and BoAHV5 genomes in its tonsils. No infectious virus could be recovered from any of the samples. The BuAHV1 sequences identified here were more closely related to BuAHV1 genomes identified in India. Phylogenetic analyses suggested a closer relationship between the recovered BoAHV5 and BuAHV1 genomes. Therefore, evidence is provided here to confirm that not only BoAHV1 and BuAHV1, but also BoAHV5, can infect water buffaloes. This report highlights (i) the first detection of BoAHV5 in water buffaloes and (ii) the occurrence of coinfections with BoAHV1 and BoAHV5 in that species. Such findings and the similarity of BoAHV5 to Indian herpesvirus genomes suggest that the origin of type 5 may be linked to recombinations between bovine and bubaline herpesviruses within bubalines, since the scenario for generation of recombinants in buffaloes is potentially present.

This study evaluated palatine tonsils from 327 water buffaloes collected in a slaughterhouse located in the city of Belém, Pará State, Brazil, over four months (nine sample collecting visits). The overwhelming majority (84.71%) of these buffaloes came from Marajó Island, Pará State, Brazil. The main pathological findings were crypt dilatations/keratin cysts (96.0%, 314 cases), mild to moderate follicular lymphoid hyperplasia (93.0%, 304 cases), crypt abscesses (79.8%, 261 cases), tonsillar corpuscles (31.2%, 102 cases) and tuberculoid granulomas (1.53%, 5 cases). Acid-fast bacilli (AFB) were observed in 20% (1 out of 5 cases) of these granulomas. The study indicates that pathological evaluation of tonsils in buffaloes can provide details of structural features of the organ in the species and information on subclinical or asymptomatic tonsillitis.

Polisserosites são alterações inflamatórias das serosas viscerais e parietais das cavidades corpóreas. Um tipo especial destas alterações foi identificado em bubalinos abatidos para consumo nos anos 80, sendo associada a infecção por Chlamydia psittaci. Apesar da importância da bubalinocultura no Pará, do caráter zoonótico da C. psittaci e da possibilidade de envolvimento de outros agentes na afecção, são raros trabalhos sobre a enfermidade desde os estudos pioneiros. No presente trabalho casos identificados como polisserosite pelo serviço de inspeção sanitária em búfalos abatidos para consumo foram coletados com objetivo de determinar a frequência e origem dos mesmos e de caracterizar as lesões e pesquisar antígenos de Chlamydia spp. nas mesmas. De um total de 2.887 bubalinos abatidos no período de estudo foram identificados 48 (1,66%) casos. O município de Santa Cruz do Arari na Ilha de Marajó apresentou a maior porcentagem de casos em relação ao número de animais abatidos (6,49%, 5/77). Na macroscopia as lesões se caracterizaram por áreas opacas, branco-amareladas de espessamento das serosas, por vezes com franjas fibrosas na superfície. Os resultados permitem concluir que os casos classificados como polisserosite pelos veterinários da inspeção sanitária nos búfalos abatidos para consumo correspondem na histopatologia a um tipo incomum de polisserosite, caracterizada por infiltrado linfocitário, com ocasionais formações de folículos linfoides terciários ou ectópicos. Foi observado ainda nestas lesões um predomínio de linfócitos T (CD3 positivos) no infiltrado, sendo os linfócitos B (CD79 positivos) presentes em maior número no interior das estruturas foliculares. Não foram demonstrados antígenos de clamídias nas lesões do presente estudo, o que demonstra a necessidade de estudos adicionais relativos a(s) etiologia(s) das lesões.