Circulação de Arbovírus dos gêneros Alphavirus, Flavivirus e Orthobunyavirus em pacientes com doença febril aguda no Mato Grosso, 2015-2016

Abstract

Arboviruses are transmitted by hematophagous arthropods, representing 30% of infectious disease events in humans and a public health concern in tropical regions. In order to investigate the epidemiological circulation of Alphavirus, Flavivirus and Orthobunyavirus species during the introduction of Zika (ZIKV) and Chikungunya (CHKV) in Mato Grosso (MT), serum samples (n=453) of patients suspected of harboring Dengue (DENV), ZIKV or CHIKV from 31 municipalities of MT were subjected to viral RNA extraction and semi-nested multiplexRT-PCR for five alphaviruses and 11 flaviviruses. Positive samples were subjected to single PCR, nucleotide sequencing and inoculation in Vero cells (alphavirus) or C6/36 cells (flaviviruses). In total 74 (16.3%) samples were positive for DENV-1 genotype V (5, 1.1%), DENV-4 genotype II (22; 4.4%), ZIKV asian genotype (5; 1.1%), Yellow Fever south American II (YFV; 3; 0.66%), Mayaro genotype L (MAYV; 34; 7.5%), CHIKV ECSA genotype (2.44%), Madariaga lineage III of EEEV (MADV; 1; 1.02%) and Oropouche Segment S genotype IA (OROV; 20; 4.4%). Four individuals were co-infected with MAYV/DENV-4, MAYV/ZIKV, DENV-4/DENV-1 and ZIKV/DENV-1. MAYV (n=8), CHIKV (n=2), MADV (n=1), DENV-4 (n=3), and DENV-1 (n=1) were isolated in Vero or C6/36 cells at passage 1-3. Among these, 20 (27%) were men and 54 (73%) women, 11 (20%) of them were pregnant and 37 (50%) were 20-39 years old. These patients are mostly residents in urban areas (72.97%) distributed in 17/31 municipalities of MT. The first human cases of ZIKV Asian genotype and CHIKV ECSA genotype in the state were detected in Tapurah in August, 2015 and Mirassol D'Oeste in July, 2015, respectively. An outbreak of MAYV infections was evidenced in Varzea Grande between May and July, 2015. In addition, a case of MADV was confirmed in a 10-yearold boy with history of constant visit to a rural area, without neurological signs, resident of Várzea Grande in October, 2015. The state of MT presents a vast territory, tropical and equatorial humid climate and diversity of biomes, vectors and vertebrate hosts in proximity to urban centers, factors favoring the circulation of arboviruses.