Zika virus transmission by Brazilian Aedes aegypti and Aedes albopictus is virus dose and temperature-dependentby Chouin-Carneiro et al.
Results indicate that Brazilian populations of Ae. aegypti exhibit a much higher transmission potential for ZIKV than Ae. albopictus.
Researchers have found that ZIKV immunity might be shorter-lived than previously thought, which may contribute to local ZIKV resurgence once individual immune responses wane sufficiently to reduce community protective immunity in addition to birth and migration.
Mapping the response to Zika, a public health emergency, demonstrated a clear pattern of the participation of countries in the scientific advances. The pattern of knowledge production found in this study represented varying country perspectives, research capacity and interests based first on their level of exposure to the epidemic and second on their financial positions regarding science.
This study reveals how the ZIKV epidemic was ignited and maintained within the largest urban metropolis in the Amazon. These results might contribute to improving the public health response to outbreaks in Brazil.
In this study the authors' data provide a convenient and practicable solution to ensure robust differentiation of CHIKV- and MAYV-specific antibodies.
Uncertainty in times of medical emergency: Knowledge gaps and structural ignorance during the Brazilian Zika crisisby Kelly et al.
Uncertainty was a defining feature of the Brazilian Zika crisis of 2015–2016. This article identifies three forms of uncertainty: global health, public health and clinical uncertainty, and it suggests that “emergency research” was effective in tackling global health uncertainty.
Spatiotemporal Analysis of the Population Risk of Congenital Microcephaly in Pernambuco State, Brazilby Alexander et al.
This study emphasizes the burden of microcephaly during the outbreak in Pernambuco, with estimates higher than in some previous studies, and with high risk in an inland region of the state for reasons which are yet to be clarified.
This study provides an understanding of how YFV initiates transmission in new Brazilian regions and illustrates that genomics in the field can augment traditional approaches to infectious disease surveillance and control.
For this study researchers collected nasopharyngeal specimens from 282 children aged ≤5 years with acute respiratory tract infection (ARI) during 2005 to 2006 in one of the largest Brazilian slums.
The results reported in this study suggest that multitypic dengue virus infection may protect from, rather than enhance, development of congenital Zika syndrome.
Zika virus infection among symptomatic patients from two healthcare centers in Sao Paulo State, Brazil: prevalence, clinical characteristics, viral detection in body fluids and serodynamicsby Tozetto-Mendoza et al.
This study shows that urine ZIKV RT-PCR testing in the acute phase of infection can improve the sensitivity of diagnosis, while testing serum is probably less useful despite more sustained shedding in some cases. Higher sensitivity and specificity serological tests are needed for the diagnosis of patients who seek medical attention after the period of ZIKV detection by RT-PCR and for surveillance purposes in settings of high DENV background infection.
This study highlights the potential of combining traditional surveillance with portable genome sequencing technologies and digital epidemiology to inform public health surveillance in the Amazon region. Data reveal a large CHIKV-ECSA outbreak in Boa Vista, limited potential for future CHIKV outbreaks, and indicate a replacement of the Asian genotype by the ECSA genotype in the Amazon region.
The association between Zika virus infection and microcephaly in Brazil 2015–2017: An observational analysis of over 4 million birthsby Brady et al.
This study strengthens the evidence that congenital ZIKV infection, particularly in the first 2 trimesters of pregnancy, is associated with microcephaly and less frequently with other birth defects. The finding of no alternative causes for geographic differences in microcephaly rate lead the authors to hypothesize that the Northeast region of Brazil was disproportionately affected by this Zika outbreak, with 94% of an estimated 8.5 million total cases occurring in this region, suggesting a need for seroprevalence surveys to determine the underlying reason.
Recurrent recent arbovirus infections suggested by serologic data and unspecific symptoms highlight the need for exhaustive virologic testing.
Potential of Aedes albopictus as a bridge vector for enzootic pathogens at the urban-forest interface in Brazilby dos Santos et al.
Results from this study show that Ae. albopictus frequency declines as it penetrates into the forest and highlight its potential role as a bridge vector of zoonotic diseases at the edge of the Brazilian forests studied.
The findings from this study suggest a possible long-term detrimental effect of ZIKV infection on human male fertility that has to be further explored in well-characterized samples from cohort studies conducted in ZIKV-endemic areas.
These results establish a framework for monitoring YFV transmission in real time that will contribute to a global strategy to eliminate future YFV epidemics.
Exhaustive TORCH Pathogen Diagnostics Corroborate Zika Virus Etiology of Congenital Malformations in Northeastern Brazilby Moreira-Soto et al.
Data from this study support a link between maternal ZIKV infection and congenital malformations and suggest the occurrence of predominantly vector-borne ZIKV transmission in these cases. In addition, some highly prevalent TORCH pathogens may be misinterpreted as representative of ongoing ZIKV activity in the absence of exhaustive diagnostics in northeastern Brazil.
A Novel Marsupial Hepatitis A Virus Corroborates Complex Evolutionary Patterns Shaping the Genus Hepatovirusby Carneiro et al.
The authors conducted field work in Brazil to sample marsupials, one of the most ancient mammalian lineages, and identified a new HAV, marsupial HAV (MHAV).
Evidence for multiple sylvatic transmission cycles during the 2016–2017 yellow fever virus outbreak, Brazilby Moreira-Soto et al.
Since December 2016, Brazil has experienced an unusually large outbreak of yellow fever (YF). Whether urb a n transmission may contribute to the extent of the outbreak is unclear. The objective of this study was to characterize YF virus (YFV) genomes and to identify spatial patterns to determine thedistribution and origin of YF cases in Minas Gerais, Espírito Santo and Rio de Janeiro, the most affected Brazilian states during the current YFV outbreak.
The authors of this study discuss gaps in the knowledge and the challenges ahead to anticipate, prevent, and control emerging and re-emerging epidemics of arboviruses in Brazil and worldwide.
Evidence for congenital Zika virus infection from neutralizing antibody titers in maternal sera, north-eastern Brazilby Moreira-Soto et al.
Results from this study suggest that despite the inter-individual variability in immune responses, the magnitude of the maternal ZIKV-specific neutralizing antibody response may prove useful to corroborate congenital ZIKV infection, contributing to reliable estimates of the manifestation index of ZIKV-associated congenital disease. Further studies will be needed to evaluate the time-course of maternal neutralizing antibody responses to identify whether a high maternal PRNT titer can be used as an early marker of congenital infection aiding potential antiviral intervention strategies.
Results from this study further indicate that viruses from northeast Brazil were important for the continental spread of ZIKV. Within Brazil, the authors find instances of virus lineage movement from northeast to southeast Brazil; most of these events are dated to the second half of 2014 and led to onwards transmission in Rio de Janeiro and São Paulo states. The authors infer that ZIKV lineages disseminated from northeast Brazil to elsewhere in Central America, the Caribbean, and South America.
Culex quinquefasciatus from areas with the highest incidence of microcephaly associated with Zika virus infections in the Northeast Region of Brazil are refractory to the virusby Fernandes et al.
The study shows that Culex quinquefasciatus should not be considered a potential vector of ZIKV in Brazil.
Based on the reported data from Brazil in 2015/16, this publication describes a plausible range for the risk of microcephaly in women who were infected with Zika virus during pregnancy compared to those who were not infected. The key message is that the large uncertainty around the risk estimate needs to be further investigated because of a) the possible existence of co-factors that are yet to be validated, b) the assumptions that need be made for the proportion of women who were infected during pregnancy.