The Challenges Imposed by Dengue, Zika, and Chikungunya to Brazil

Abstract

Brazil has a well-established immunization program in which vaccines are provided through the Public Health System free of charge to the whole population, obtaining high coverage and reducing the incidence of important infectious diseases in children and adults. However, the environmental changes and high mobility rates of the population occurring in the last decades have triggered the sequential introduction of a series of vector-borne emerging infectious diseases, such as Dengue, Zika, and Chikungunya, that have imposed a considerable burden on the population, with yet unmet solutions. The first to be introduced in Brazil was the Dengue virus, reaching epidemic levels in 2010, with over 1 million cases annually, maintaining high infection rates until 2016. Brazil has invested in vaccine development. The Zika virus infection, initially assumed to have appeared during the World Cup in 2014, was later shown to have arrived earlier in 2013. Its emergence mobilized the Brazilian scientific community to define priorities and strategies, that rapidly investigated mechanisms of pathogenesis, differential diagnostics, and determined that Zika virus infection per se causes relatively mild symptoms, however, in pregnant women can cause microcephaly in the newborns. The diagnostics of Zika infection is confusing given its similar symptoms and cross-reactivity with Dengue, which also hindered the appraisal of the extent of the epidemics, which peaked in 2015 and finished in 2016. Another complicating factor was the overlap with Chikungunya virus infection, which arrived in Brazil in 2014, being prevalent in the same regions, with similar symptoms to both Dengue and Zika. Although Dengue infection can be fatal and Zika infection in pregnant woman can lead to newborns with microcephaly or an array of neurodegenerative manifestations, the Chikungunya infection is a debilitating disease leaving chronic sequelae, which unfortunately has received less attention. Precise differential diagnostics of Dengue, Zika, and Chikungunya will be necessary to evaluate the actual extent of each of these diseases during this overlapping period. Here we review the impact of these emerging infections on public health and how the scientific community was mobilized to deal with them in Brazil.

ZIKV Demonstrates Minimal Pathologic Effects and Mosquito Infectivity in Viremic Cynomolgus Macaques

“…Our macaques had all been exposed to CHIKV, a potential confounding element that could not be analyzed the absence of unexposed controls. However, such pre-exposure is nonetheless epidemiologically relevant due to the near simultaneous arrival of CHIKV and ZIKV in the Americas in 2013, with CHIKV causing major outbreaks in 2013-2014 before being overshadowed by ZIKV in 2015-2016 [ 100 , 101 , 102 , 103 , 104 ]. Given previously immunologically naïve populations involved, it not surprising that many concomitant and sequential infections have been reported [ 105 , 106 , 107 ].…”

Human immunodeficiency virus infection (HIV)–associated rheumatic manifestations in thepre- and post-HAART eras

“…Several factors contributing to the emergence of recent epidemics have been identified, including genetic adaptations of the microbial agent, international travel, human susceptibility to infection, population growth, an aging population, climate and weather changes, and expanding vector habitats [2][3][4][5]. Four recent examples of disease emergences are the viral infections such as Chikungunya, Zika, Middle East Respiratory syndrome coronavirus (MERS-CoV), and the recently described novel coronavirus (COVID- 19) infection, which represent new viral entities or viruses emergent in new geographic locales and characterized by novel complications [6][7][8]. However, the most important newest example of an emergent infectious disease is HIV infection, which emerged a century ago in a primate host(s), and subsequently spread within the human population.…”

Mosquito-Borne Viral Diseases: Control and Prevention in the Genomics Era

“…Neglected tropical diseases are a group of diseases that have received insufficient public attention, strive in tropical and subtropical areas, and strongly affect populations living in poverty [12]. It is argued that arboviruses can be considered a group of neglected tropical diseases, since they can have a long-lasting impact in the health and economic life of affected populations [16]. Some studies have argued that socioeconomic factors and land-use changes associated with the effects of climate change and global travel, and trade modulate the dynamics of expansion of emerging e re-emerging mosquito-borne diseases [17][18][19][20].…”