Field validation of the performance of paper-based tests for the detection of the Zika and chikungunya viruses in serum samplesby Margot Karlikow et al.
In low-resource settings, resilience to infectious disease outbreaks can be hindered by limited access to diagnostic tests. Here we report the results of double-blinded studies of the performance of paper-based diagnostic tests for the Zika and chikungunya viruses in a field setting in Latin America. The tests involved a cell-free expression system relying on isothermal amplification and toehold-switch reactions, a purpose-built portable reader and onboard software for computer vision-enabled image analysis. In patients suspected of infection, the accuracies and sensitivities of the tests for the Zika and chikungunya viruses were, respectively, 98.5% (95% confidence interval, 96.2–99.6%, 268 serum samples) and 98.5% (95% confidence interval, 91.7–100%, 65 serum samples) and approximately 2 aM and 5 fM (both concentrations are within clinically relevant ranges). The analytical specificities and sensitivities of the tests for cultured samples of the viruses were equivalent to those of the real-time quantitative PCR. Cell-free synthetic biology tools and companion hardware can provide de-centralized, high-capacity and low-cost diagnostics for use in low-resource settings.
This is the first report of mosquitoes infected with CHIKV in Iran. The high-throughput screening method here presented can be proposed as a novel epidemiological surveillance tool to identify circulating arboviruses and to support preparedness to an epidemic in animals and humans.
Based on vector competence data and vector distribution, the auhtors generate a prediction risk map for CHIKV stressing the fear of CHIKV and to a lesser extent, of other arboviruses for Europe, calling us for new public health strategies.
Assessing the Potential Interactions between Cellular miRNA and Arboviral Genomic RNA in the Yellow Fever Mosquito, Aedes aegyptiby Yen et al.
This study shows a broad picture of possible interactions between mosquito cellular miRNAs and the viral RNA of different genotypes/lineages of arboviruses, providing a list of mosquito cellular miRNAs candidates for experimental validations in future studies.
A computational method for the identification of Dengue, Zika and Chikungunya virus species and genotypesby Fonseca et al.
In this study, the authors developed an efficient method to classify virus sequences with respect to their species and sub-species (i.e. serotype and/or genotype).
This study offers an opportunity to strategically target surveillance and control programmes and thereby augment efforts to reduce arbovirus burden in human populations globally.
In this study, the authors determined the global proteomic profile of CHIKV and ZIKV infections in human skin fibroblasts using Stable Isotope Labelling by Amino acids in Cell culture (SILAC)-based mass-spectrometry analysis.
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.
Results obtained in this study suggest that the local transmission of four arboviruses - dengue (DENV), chikungunya (CHIKV), zika (ZIKV) and yellow fever (YFV) viruses - by Ae. albopictus newly introduced in Morocco is a likely scenario.
Recurrent recent arbovirus infections suggested by serologic data and unspecific symptoms highlight the need for exhaustive virologic testing.
The model provided in this study correctly estimates the number of imported cases and can be easily adapted to other urban areas where Ae. albopictus is the only potential vector present.
The authors conclude that ZIKV has been circulating in Bolivian tropical areas but not in highlands, and that the epidemic has not been limited by previous immunity against dengue. Specific attention should be paid to the region of Santa Cruz, where the seroprevalence is still limited, but the density of Aedes aegypti populations makes plausible further spreading of the disease.
Limited Evidence for Infection of Urban and Peri-urban Nonhuman Primates with Zika and Chikungunya Viruses in Brazilby Moreira-Soto et al.
The authors of this study tested nonhuman primates (NHP) sampled during 2012 to 2017 in urban and peri-urban areas severely affected by ZIKV and CHIKV in Brazil. Seroprevalence and antibody titers were low for both viruses. Additionally, they found evidence for infection by heterologous viruses eliciting cross-reactive antibodies. These data suggest that urban or peri-urban NHP are not easily infected by ZIKV and CHIKV despite intense local transmission, and they may also imply that the ZIKV and CHIKV outbreaks in the Americas cannot be sustained in urban or peri-urban NHP once human population immunity limits urban transmission cycles.
The findings of this study have implications for the development of multifaceted infection control programs, including strategies for prevention and awareness, helping the population to develop an accurate perception of the threat they are facing and encouraging behavior changes.
In 2015–2016 in the Recife Metropolitan Region, the authors of this study detected the tail end of a Zika epidemic, which was displaced by a chikungunya epidemic. Few dengue cases were identified despite a high number of official dengue notifications in the area during this period. This study shows here important epidemiological features of these cases.