Sera of Peruvians with fever of unknown origins include viral nucleic acids from non-vertebrate hosts

Abstract

Serum samples collected from 88 Peruvians with unexplained fever were analyzed for viral sequences using metagenomics. Nucleic acids of anelloviruses, pegivirus A (GBV-C), HIV, Dengue virus, and Oropouche virus were detected. We also characterized from two sera the RNA genomes of new species of partitivirus and dicistrovirus belonging to viral families known to infect fungi or arthropod, respectively. Genomic DNA of a putative fungal cellular host could be PCR amplified from the partitivirus-containing serum sample. The detection in human serum of nucleic acids from viral families not known to infect vertebrates may indicate contamination during sample collection and aliquoting or human infection by their presumed cellular host, here a fungus. The role, if any, of the non-vertebrate infecting viruses detected in serum in inducing fever is unknown.

Keywords: Dicistrovirus; Fever; Metagenomics; Partitivirus; Sera.

Figure 1. New dicistrovirus

A. Genome organization. B. Phylogenetic trees generated with non-structural and structural polyproteins of dicistrovirus detected in a Peruvian patient with unexplained fever and all genetically-related dicistroviruses in the family Dicistroviridae. The scale indicates amino acid substitutions per position.

Figure 2. New partitivirus

A. Genome organization. B. Phylogenetic trees generated with non-structural and structural proteins of partitivirus detected in a Peruvian patient with unexplained fever and all genetically-related partitiviruses in the family Partitiviridae. The scale indicates amino acid substitutions per position.

Figure 3. Fungal DNA amplification

The PCR assay with universal fungal primers ITS1 and ITS2 was performed. The partitivirus-positive serum sample was found positive for fungal DNA and other eighteen HuBDV-negative serum samples were negative.