Lethal Canine Distemper Virus () Outbreak in Free-Ranging Black-Tufted Marmosets () in Brazil: Clinical, Pathological, Genotypical Evaluation, and Assessment of Viral Tropism.

Abstract

Canine distemper virus (CDV;) is a morbillivirus with worldwide distribution. The virus belongs to the family Paramyxoviridae, which includes highly pathogenic viruses such as measles virus (MeV) () and rinderpest virus (). Canine distemper is primarily a disease in domestic dogs, but it has been described in terrestrial and aquatic wild mammals, demonstrating the ability of CDV to cross species barriers. Here, we describe a lethal CDV outbreak in free-ranging marmosets () in Brazil. The marmosets were captured during a targeted epidemiological surveillance program aimed at monitoring viral agents in wildlife in urban parks of Belo Horizonte, Minas Gerais, Brazil. Affected marmosets presented with neurological signs, and others were found dead in the same area. In this report, we detail the occurrence of the outbreak and describe clinical manifestations, gross and histopathological lesions, tissue distribution of the virus by immunohistochemistry (IHC) and molecular methods, and phylogenetic analyses of the virus. This study demonstrated that CDV can infect free-ranging black-tufted marmosets and lead to neurologic signs, cutaneous lesions, and death. Viral genomic sequences and antigens were detected in several organs, indicating a pantropic distribution of CDV in this neotropical primate species. Additionally, the marmosets were also tested for MeV and, which yielded negative results. Coinfections with CDV and3 were detected in three marmosets. The CDV sequences identified here were closely related to both South American sequences and Vero cell-adapted lineages. These findings have significant implications from a One Health perspective.