Analysis of spatial and demographic factors associated with chikungunya in Espírito Santo state, Brazil.

BACKGROUND: Chikungunya (CHIK) emerged in Brazil in 2014 and since then several epidemics have been observed. This study aims to describe the spatial, social and demographic characteristics of individuals affected by CHIK in Espírito Santo state. METHODS: A cross-sectional study was performed using data from individuals with a confirmed diagnosis of CHIK in Espírito Santo state, Brazil, from 2018 to 2020. Monthly incidence was calculated and annual spatial distribution maps were constructed. Statistical analysis using the χ2 test identified associations between disease occurrence and sociodemographic variables. RESULTS: In the period and area analysed, a CHIK epidemic occurred in 2020, with an incidence of 219.8 cases per 100 000 inhabitants. The southern and central regions of Espirito Santo state harboured a risk five times greater than the others in the epidemic region. Females (odds ratio [OR] 1.65 [95% confidence interval {CI} 1.58 to 1.72]), black people (OR 1.22 [95% CI 1.13 to 1.33]), individuals with ≤11 y of education (OR 1.48 [95% CI 1.37 to 1.61]) and the elderly (OR 7.49 [95% CI 6.53 to 8.59]) had a greater risk for the disease. CONCLUSIONS: CHIK stands as an emerging public health problem in Brazil since its introduction in 2014. Espírito Santo suffered a substantial epidemic in 2020, possibly due to outbreaks in neighbouring states. The population at risk should be prioritized in healthcare, considering the morbidity potential of the disease.

First report of Aedes albopictus infected by Dengue and Zika virus in a rural outbreak in Brazil.

In Brazil, Dengue (DENV) and Zika (ZIKV) viruses are reported as being transmitted exclusively by Aedes aegypti in urban settings. This study established the vectors and viruses involved in an arbovirus outbreak that occurred in 2019 in a rural area of Espírito Santo state, Brazil. Mosquitoes collected were morphologically identified, sorted in samples, and submitted to molecular analysis for arboviruses detection. Phylogenetic reconstruction was performed for the viral sequence obtained. All 393 mosquitoes were identified as Aedes albopictus. DENV-1 genotype V was present in one sample and another sample was positive for ZIKV. The DENV-1 clustered with viruses that have circulated in previous years in large urban centers of different regions in Brazil. This is the first report of A. albopictus infected by DENV and ZIKV during an outbreak in a rural area in Brazil, indicating its involvement in arboviral transmission. The DENV-1 strain found in the A. albopictus was not new in Brazil, being involved previously in epidemics related to A. aegypti, suggesting the potential to A. albopictus in transmitting viruses already circulating in the Brazilian population. This finding also indicates the possibility of these viruses to disperse across urban and rural settings, imposing additional challenges for the control of the diseases.