Dynamics of Transmission of Urban Arbovirus Dengue, Zika and Chikungunya in Southwestern Region of Bahia, Brazil.

Jose Herberto M Souza,Robson A.A Silva,Laize Tomazi,Tácita B Barros,Suze C.A Vieira,Palloma P Almeida,Fabrício F Melo

doi:10.1590/0001-3765202120200670

Abstract

Arboviral diseases are disseminated all over the world. In Brazil, they remain neglected, alerting public authorities to possible outbreaks. Over here, we report the epidemiological indicators of Dengue from 2010 to 2015, Zika between 2015 and 2016, and Chikungunya from 2014 to 2016, within 19 municipalities of Southwestern Region of Bahia, Brazil. The data were collected from Brazilian national public information systems (SISFAD, SINAN, and IBGE) and by Endemic Control Agents. The analysis consisted of a description of vector characteristics, Home Infestation Index and characterization of human reported cases. The years 2011 and 2013 were recorded as having the highest frequencies of positive properties for the presence of the arboviruse vectors. Most municipalities presented high annual values of Home Infestation Index indicating an alert situation (62.28%). In the evaluated period, there were (i) 9,196 cases of Dengue, (ii) 636 cases of Zika and (iii) 224 cases of Chikungunya reported. This is the first report of the epidemiological characteristics of these arboviruses in the 19 municipalities of Bahia. It is believed that the data collected may contribute to public health policies aimed at controlling future epidemics of these arboviruses.

Highlights

Dengue (DENV), Zika (ZIKV), and Chikungunya (CHIKV) are arboviruses, widely considered a global threat to public health and wellbeing, especially in tropical countries
In the period from 2010 to 2015, across the 19 municipalities inspected by Endemic Diseases Control agents, there were 8,504,334 properties agreed upon; 942,934 inspected; 21,215 positive properties and 1,361,837 properties treated (Supplementary Material – Table SI)
We demonstrated for the first time the epidemiological characteristics of DENV, ZIKV, and CHIVK in the 19 municipalities of Southwestern Region of Bahia

Summary

Introduction

Dengue (DENV), Zika (ZIKV), and Chikungunya (CHIKV) are arboviruses, widely considered a global threat to public health and wellbeing, especially in tropical countries. Due to the Americas’ climatic conditions, the rapid dispersion and proliferation of the mosquito vectors Aedes aegypti and Aedes albopictus are favored (Bhatt et al 2013) The epidemiology of these three arboviruses and the behavior of the vector are affected by factors such as: (i) demographic changes in human populations (ii) urbanization (iii) volume of international traffic (iv) failure of vector control programs (v) precariousness of basic sanitation. Climate and temperature affect the incubation period and the proportion of mosquitoes capable of transmitting arboviruses. These factors can generate changes in biodiversity that facilitate the permanence of the vector and its reproduction (Bhatt et al 2013, Helmersson et al 2014, Chediak et al 2016, Alto et al 2017, Zanotto & Leite 2018, Vieira et al 2019). In Brazil, according data from the Ministry of Health, from December / 2019 to April / 2020, 603,951 probable DENV cases were recorded

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