scholarly journals SIR-SI Mathematical Model for Zika Virus Progression Dynamics in India: A Case Study

2021 ◽  
Vol 53 (02) ◽  
pp. 100-104
Author(s):  
Surendra Kumar Sagar ◽  

Viral diseases are very hazardous for humanity because in the case of most viral diseases, drugs are not effective. At present, the whole world is living with the fear of COVID-19. From time to time, several viral diseases have been troubling human life. In this article, we have tried to capture the progression dynamics of Zika Virus (ZIKV) infection in the Indian scenario. A constructed model is based on compartment modelling. In the model, Susceptible-Infected-Recovered (SIR) structure is used for the human population and Susceptible-Infected (SI) structure is used for mosquito population. The value of the basic reproduction number (R0) is computed 0.36 at baseline values of parameters involved in the model. The lower value of R0 suggests that infection was unable to spread in the human population. Sensitive analysis for R0 revealed that the most accountable parameter in the spread of infection was mosquito biting rate. The modelling technique might be useful for other diseases also.

2021 ◽  
Vol 118 (47) ◽  
pp. e2115410118
Author(s):  
Sumit Sen Santara ◽  
Ângela C. Crespo ◽  
Sachin Mulik ◽  
Cristian Ovies ◽  
Selma Boulenouar ◽  
...  

Zika virus (ZIKV) during pregnancy infects fetal trophoblasts and causes placental damage and birth defects including microcephaly. Little is known about the anti-ZIKV cellular immune response at the maternal–fetal interface. Decidual natural killer cells (dNK), which directly contact fetal trophoblasts, are the dominant maternal immune cells in the first-trimester placenta, when ZIKV infection is most hazardous. Although dNK express all the cytolytic molecules needed to kill, they usually do not kill infected fetal cells but promote placentation. Here, we show that dNK degranulate and kill ZIKV-infected placental trophoblasts. ZIKV infection of trophoblasts causes endoplasmic reticulum (ER) stress, which makes them dNK targets by down-regulating HLA-C/G, natural killer (NK) inhibitory receptor ligands that help maintain tolerance of the semiallogeneic fetus. ER stress also activates the NK activating receptor NKp46. ZIKV infection of Ifnar1−/− pregnant mice results in high viral titers and severe intrauterine growth restriction, which are exacerbated by depletion of NK or CD8 T cells, indicating that killer lymphocytes, on balance, protect the fetus from ZIKV by eliminating infected cells and reducing the spread of infection.


2020 ◽  
Author(s):  
George Karagiannakis

This paper deals with state of the art risk and resilience calculations for industrial plants. Resilience is a top priority issue on the agenda of societies due to climate change and the all-time demand for human life safety and financial robustness. Industrial plants are highly complex systems containing a considerable number of equipment such as steel storage tanks, pipe rack-piping systems, and other installations. Loss Of Containment (LOC) scenarios triggered by past earthquakes due to failure on critical components were followed by severe repercussions on the community, long recovery times and great economic losses. Hence, facility planners and emergency managers should be aware of possible seismic damages and should have already established recovery plans to maximize the resilience and minimize the losses. Seismic risk assessment is the first step of resilience calculations, as it establishes possible damage scenarios. In order to have an accurate risk analysis, the plant equipment vulnerability must be assessed; this is made feasible either from fragility databases in the literature that refer to customized equipment or through numerical calculations. Two different approaches to fragility assessment will be discussed in this paper: (i) code-based Fragility Curves (FCs); and (ii) fragility curves based on numerical models. A carbon black process plant is used as a case study in order to display the influence of various fragility curve realizations taking their effects on risk and resilience calculations into account. Additionally, a new way of representing the total resilience of industrial installations is proposed. More precisely, all possible scenarios will be endowed with their weighted recovery curves (according to their probability of occurrence) and summed together. The result is a concise graph that can help stakeholders to identify critical plant equipment and make decisions on seismic mitigation strategies for plant safety and efficiency. Finally, possible mitigation strategies, like structural health monitoring and metamaterial-based seismic shields are addressed, in order to show how future developments may enhance plant resilience. The work presented hereafter represents a highly condensed application of the research done during the XP-RESILIENCE project, while more detailed information is available on the project website https://r.unitn.it/en/dicam/xp-resilience.


2021 ◽  
Vol 13 (11) ◽  
pp. 6478
Author(s):  
Amemarlita Matos ◽  
Laura Barraza ◽  
Isabel Ruiz-Mallén

This study is based on ethnographic research that analyzes how traditional knowledge and local beliefs on biodiversity conservation relates to the local ability to adapt and be resilient to climatic changes in two communities around Gorongosa National Park, Mozambique: Nhanfisse in the buffer zone and Muanandimae in the core area. A total of 78 semi-structured interviews with heads of households were conducted. We found that both communities carried out practices and held beliefs associated with conservation, such as protecting trees and animal species considered sacred or perceived as beneficial for human life in terms of water provision and agricultural production. In addition to traditional ceremonies that respond to extreme climatic events such as drought and flood, other adaptation strategies used by the communities include moving to neighboring areas in search of better living conditions and using forest products in times of scarcity. We discuss that the management of the park should be agreed on, in a shared way, between local communities and conservation agents to ensure that these areas continue to perform the ecological, subsistence, and spiritual functions required. Our research results contribute to a better understanding of local adaptation dynamics towards extreme climatic events and improvement of management strategies.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rafael Corrêa ◽  
Igor de Oliveira Santos ◽  
Heloísa Antoniella Braz-de-Melo ◽  
Lívia Pimentel de Sant’Ana ◽  
Raquel das Neves Almeida ◽  
...  

AbstractGut microbiota composition can modulate neuroendocrine function, inflammation, and cellular and immunological responses against different pathogens, including viruses. Zika virus (ZIKV) can infect adult immunocompetent individuals and trigger brain damage and antiviral responses. However, it is not known whether ZIKV infection could impact the gut microbiome from adult immunocompetent mice. Here, we investigated modifications induced by ZIKV infection in the gut microbiome of immunocompetent C57BL/6J mice. Adult C57BL/6J mice were infected with ZIKV and the gut microbiota composition was analyzed by next-generation sequencing of the V4 hypervariable region present in the bacterial 16S rDNA gene. Our data showed that ZIKV infection triggered a significant decrease in the bacteria belonging to Actinobacteria and Firmicutes phyla, and increased Deferribacteres and Spirochaetes phyla components compared to uninfected mice. Interestingly, ZIKV infection triggered a significant increase in the abundance of bacteria from the Spirochaetaceae family in the gut microbiota. Lastly, we demonstrated that modulation of microbiota induced by ZIKV infection may lead to intestinal epithelium damage and intense leukocyte recruitment to the intestinal mucosa. Taken together, our data demonstrate that ZIKV infection can impact the gut microbiota composition and colon tissue homeostasis in adult immunocompetent mice.


Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 325
Author(s):  
Julia A. Gomes ◽  
Eduarda Sgarioni ◽  
Juliano A. Boquett ◽  
Ana Cláudia P. Terças-Trettel ◽  
Juliana H. da Silva ◽  
...  

Zika virus (ZIKV) causes Congenital Zika Syndrome (CZS) in individuals exposed prenatally. Here, we investigated polymorphisms in VEGFA, PTGS2, NOS3, TNF, and NOS2 genes as risk factors to CZS. Forty children with CZS and forty-eight children who were in utero exposed to ZIKV infection, but born without congenital anomalies, were evaluated. Children with CZS were predominantly infected by ZIKV in the first trimester (p < 0.001) and had mothers with lower educational level (p < 0.001) and family income (p < 0.001). We found higher risk of CZS due the allele rs2297518[A] of NOS2 (OR = 2.28, CI 95% 1.17–4.50, p = 0.015). T allele and TT/CT genotypes of the TNF rs1799724 and haplotypes associated with higher expression of TNF were more prevalent in children with CZS and severe microcephaly (p = 0.029, p = 0.041 and p = 0.030, respectively). Our findings showed higher risk of CZS due ZIKV infection in the first trimester and suggested that polymorphisms in NOS2 and TNF genes affect the risk of CZS and severe microcephaly.


Viruses ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 91
Author(s):  
Verena Schultz ◽  
Stephanie L. Cumberworth ◽  
Quan Gu ◽  
Natasha Johnson ◽  
Claire L. Donald ◽  
...  

Understanding how Zika virus (Flaviviridae; ZIKV) affects neural cells is paramount in comprehending pathologies associated with infection. Whilst the effects of ZIKV in neural development are well documented, impact on the adult nervous system remains obscure. Here, we investigated the effects of ZIKV infection in established mature myelinated central nervous system (CNS) cultures. Infection incurred damage to myelinated fibers, with ZIKV-positive cells appearing when myelin damage was first detected as well as axonal pathology, suggesting the latter was a consequence of oligodendroglia infection. Transcriptome analysis revealed host factors that were upregulated during ZIKV infection. One such factor, CCL5, was validated in vitro as inhibiting myelination. Transferred UV-inactivated media from infected cultures did not damage myelin and axons, suggesting that viral replication is necessary to induce the observed effects. These data show that ZIKV infection affects CNS cells even after myelination—which is critical for saltatory conduction and neuronal function—has taken place. Understanding the targets of this virus across developmental stages including the mature CNS, and the subsequent effects of infection of cell types, is necessary to understand effective time frames for therapeutic intervention.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rommel J. Gestuveo ◽  
Jamie Royle ◽  
Claire L. Donald ◽  
Douglas J. Lamont ◽  
Edward C. Hutchinson ◽  
...  

AbstractThe escalating global prevalence of arboviral diseases emphasizes the need to improve our understanding of their biology. Research in this area has been hindered by the lack of molecular tools for studying virus-mosquito interactions. Here, we develop an Aedes aegypti cell line which stably expresses Zika virus (ZIKV) capsid proteins in order to study virus-vector protein-protein interactions through quantitative label-free proteomics. We identify 157 interactors and show that eight have potentially pro-viral activity during ZIKV infection in mosquito cells. Notably, silencing of transitional endoplasmic reticulum protein TER94 prevents ZIKV capsid degradation and significantly reduces viral replication. Similar results are observed if the TER94 ortholog (VCP) functioning is blocked with inhibitors in human cells. In addition, we show that an E3 ubiquitin-protein ligase, UBR5, mediates the interaction between TER94 and ZIKV capsid. Our study demonstrates a pro-viral function for TER94/VCP during ZIKV infection that is conserved between human and mosquito cells.


Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1427
Author(s):  
Paula Sobral da Silva ◽  
Sophie Eickmann ◽  
Ricardo Ximenes ◽  
Celina Martelli ◽  
Elizabeth Brickley ◽  
...  

The relation of Zika virus (ZIKV) with microcephaly is well established. However, knowledge is lacking on later developmental outcomes in children with evidence of maternal ZIKV infection during pregnancy born without microcephaly. The objective of this analysis is to investigate the impact of prenatal exposure to ZIKV on neuropsychomotor development in children without microcephaly. We evaluated 274 children including 235 ZIKV exposed and 39 controls using the Bayley-III Scales of Infant and Toddler Development (BSIDIII) and neurological examination. We observed a difference in cognition with a borderline p-value (p = 0.052): 9.4% of exposed children and none of the unexposed control group had mild to moderate delays. The prevalence of delays in the language and motor domains did not differ significantly between ZIKV-exposed and unexposed children (language: 12.3% versus 12.8%; motor: 4.7% versus 2.6%). Notably, neurological examination results were predictive of neurodevelopmental delays in the BSIDIII assessments for exposed children: 46.7% of children with abnormalities on clinical neurological examination presented with delay in contrast to 17.8% among exposed children without apparent neurological abnormalities (p = 0.001). Overall, our findings suggest that relative to their unexposed peers, ZIKV-exposed children without microcephaly are not at considerably increased risk of neurodevelopmental impairment in the first 42 months of life, although a small group of children demonstrated higher frequencies of cognitive delay. It is important to highlight that in the group of exposed children, an abnormal neuroclinical examination may be a predictor of developmental delay. The article contributes to practical guidance and advances our knowledge about congenital Zika.


Viruses ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 123
Author(s):  
Elizabeth Centeno-Tablante ◽  
Melisa Medina-Rivera ◽  
Julia L. Finkelstein ◽  
Heather S. Herman ◽  
Pura Rayco-Solon ◽  
...  

We systematically searched regional and international databases and screened 1658 non-duplicate records describing women with suspected or confirmed ZIKV infection, intending to breastfeed or give breast milk to an infant to examine the potential of mother-to-child transmission of Zika virus (ZIKV) through breast milk or breastfeeding-related practices. Fourteen studies met our inclusion criteria and inform this analysis. These studies reported on 97 mother–children pairs who provided breast milk for ZIKV assessment. Seventeen breast milk samples from different women were found positive for ZIKV via RT-PCR, and ZIKV replication was found in cell cultures from five out of seven breast milk samples from different women. Only three out of six infants who had ZIKV infection were breastfed, no evidence of clinical complications was found to be associated with ZIKV RNA in breast milk. This review updates our previous report by including 12 new articles, in which we found no evidence of ZIKV mother-to-child transmission through breast milk intake or breastfeeding. As the certainty of the present evidence is low, additional studies are still warranted to determine if ZIKV can be transmitted through breastfeeding.


Author(s):  
Juan P Aguilar Ticona ◽  
Huma Baig ◽  
Nivison Nery Jr. ◽  
Simon Doss-Gollin ◽  
Gielson A Sacramento ◽  
...  

Abstract In order to understand the disease burden of sexually transmitted Zika virus (ZIKV), we prospectively followed a cohort of 359 adult and adolescent residents of an urban community in Salvador, Brazil through the 2015 ZIKV epidemic. Later, in 2017, we used a retrospective survey to associate sexual behavior during the epidemic with ZIKV infection as defined by IgG3-NS1 ELISA. We found that males who engaged in casual sexual encounters during the epidemic were more likely (ORa=6.2; 95%CI 1.2–64.1) to be ZIKV positive, suggesting that specific groups may be at increased risk of sexually transmitted infections.


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