Name: DIEGO DO PRADO VENTORIM
Publication date: 05/03/2018
Advisor:
Name |
Role |
|---|---|
| IURI DRUMOND LOURO (M/D) | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| DEBORA DUMMER MEIRA | Internal Examiner * |
| IURI DRUMOND LOURO (M/D) | Advisor * |
| MARCELO DOS SANTOS | External Examiner * |
Summary: Chikungunya fever is a highly debilitating arbovirose, caused by chikungunya virus, which is transmitted by the bite of Aedes genus mosquitoes. In 2014, the first disease cases were registered in Brazil, with Asian and East/Central/South African virus genotypes presence. At the end of 2015, for the first time, cases were reported in Espírito Santo (ES) and between 2016-2017 the state faced a disease outbreak. Thus, we, along with the State Department of Health/ES and the Central Laboratory/ES, aim to identify which virus strain circulates in ES; analyze viral genetic characteristics in the samples studied and to collect epidemiological data about the disease in the state. Study samples came from Central Laboratory/ES and refer from March 2016 to December 2017. Viral diagnosis was performed by serology or by molecular techniques. Twenty-seven samples (molecularly diagnosed) were used in the partial amplification and sequencing of two genes encoding viral envelope proteins, E1 and E2. Six of these samples were used in phylogenetic analyzes. Epidemiological results demonstrated that during the study period, 2,021 suspected cases of chikungunya fever were reported, of which 412 (20.38%) were confirmed. In addition, geographical distribution of these cases showed that Vitória and Vila Velha represented more than 50% of all cases in the state. The findings showed that frequency of chikungunya virus infection, in relation to the number of samples referred to Central Laboratory/ES, can be considered low. However, it was verified that the disease presents epidemiological relevance and high distribution in the state. Phylogenetic results showed that the circulating virus belongs to East/Central/South African lineage, which has also been observed in several outbreaks in Europe, Africa and Asia. Moreover, molecular characterization of E1 and E2 protein fragments did not show the presence of adaptive mutations E1-K211E; E1-A226V; E2-L210Q and E2-I211T. This result suggests that circulating
virus in ES has lower potential for dissemination compared to circulating viruses in recent major global epidemics. Due to the lack of a vaccine and the difficulty in mosquito vector control, genetic diversity studies such as this one, become feasible alternatives in search of better understanding and chikungunya fever control in Brazil and, specifically, in ES.
