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.
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.
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.