Norovirus strains in patients with acute gastroenteritis in rural and low-income urban areas in northern Brazil.

From 2010-2016, a total of 251 stool samples were screened for norovirus using next-generation sequencing (NGS) followed by phylogenetic analysis to investigate the genotypic diversity of noroviruses in rural and low-income urban areas in northern Brazil. Norovirus infection was detected in 19.9% (50/251) of the samples. Eight different genotypes were identified: GII.4_Sydney[P31] (64%, 32/50), GII.6[P7] (14%, 7/50), GII.17[P17] (6%, 3/50), GII.1[P33] (6%, 3/50), GII.3[P16] (4%, 2/50), GII.2[P16] (2%, 1/50), GII.2[P2] (2%, 1/50), and GII.4_New Orleans[P4] (2%, 1/50). Distinct GII.6[P7] variants were recognized, indicating the presence of different co-circulating strains. Elucidating norovirus genetic diversity will improve our understanding of their potential health burden, in particular for the GII.4_Sydney[P31] variant.

Re-emergence of mayaro virus and coinfection with chikungunya during an outbreak in the state of Tocantins/Brazil.

OBJECTIVE: To perform a molecular screening to detect infections by the mayaro virus and possible coinfections with Chikungunya during an outbreak in the state of Tocantins/Brazil in 2017. RESULTS: Of a total 102 samples analyzed in this study, 6 cases were identified with simultaneous infection between mayaro and chikungunya viruses (5.88%). In these 6 samples, the mean Cycle threshold (Ct) for CHIKV was 26.87 (SD ± 10.54) and for MAYV was 29.58 (SD ± 6.34). The mayaro sequences generated showed 95-100% identity to other Brazilian sequences of this virus and with other MAYV isolates obtained from human and arthropods in different regions of the world. The remaining samples were detected with CHIKV monoinfection (41 cases), DENV monoinfection (50 cases) and coinfection between CHIKV/DENV (5 cases). We did not detect MAYV monoinfections.