Zika virus (ZIKV) is infamous among flaviviruses for its unique association with congenital birth defects, notably microcephaly. We previously mapped ZIKV-host protein interactions and identified the interaction between ZIKV NS4A and host ANKLE2, which itself has established ties to congenital microcephaly. In fruit flies, NS4A induces microcephaly phenotypes in an ANKLE2-dependent manner. This suggests that NS4A interacts with ANKLE2 to dysregulate cell behavior and contributes to abnormal host neurodevelopment. Here, we explore the role of ANKLE2 in ZIKV replication to understand the biological significance of the interaction from the viral perspective. We show that knockdown of ANKLE2 reduces replication of two ZIKV strains, across multiple MOIs and timepoints. We observe that localization of ANKLE2 is drastically shifted to sites of NS4A accumulation during infection. We investigate which domains of ANKLE2 mediate this behavior and the interaction with NS4A. Using co-immunoprecipitation, we show that deletion of either the transmembrane or LEM domain has little impact on the interaction, but deletion of both significantly reduces interaction with NS4A. We show that the C-terminal transmembrane domains of NS4A stabilize the interaction with ANKLE2. Finally, we explore this interaction in other flaviviruses and observe ANKLE2 interacts with NS4A across four additional mosquito-borne flaviviruses. Together, these results suggest NS4A interacts with ANKLE2 through a combination of its transmembrane and LEM domains, bringing it to sites of ZIKV replication to promote replication through an unknown mechanism. Taken together with our previous results, our findings indicate that, in the process of hijacking ANKLE2 for replication, ZIKV disrupts its physiological function to cause disease. Importance The ZIKV epidemic led to the astonishing revelation that congenital ZIKV infection is associated with devastating birth defects, including microcephaly. Microcephaly is the condition in which head and brain size are severely reduced, and is often accompanied by intellectual disability. The molecular mechanisms by which ZIKV replicates and causes microcephaly are still incompletely understood. We previously identified the protein interaction between ZIKV NS4A and host ANKLE2, which is associated with congenital microcephaly. In flies, NS4A induces microcephaly in an ANKLE2-dependent manner, suggesting this interaction is crucial for ZIKV pathogenesis. Here, we explore the relevance of this physical interaction for virus replication. We find that ANKLE2 promotes ZIKV replication, concentrates at sites of NS4A accumulation during infection, and interacts with NS4A via its N-terminal domain. Thus, this represents a rare example of a ZIKV-host protein interaction that impacts both disease and virus replication.

The European Union (EU) is one of the oldest dialogue partners of the Association of Southeast Asian Nations (ASEAN). Relations between the two blocs began in 1972 and were initially focused on trade and investments. Over the years, ASEAN-EU relations expanded and developed to include economic, cultural, and political matters. In 2020, relations between the two have been upgraded into a strategic partnership solidifying the commitment of both parties to cooperate on various key areas. Recently, environmental and climate issues have also been emphasised by the two groups, leading to the establishment of the High-Level Dialogue on Environment and Climate Change in 2019. The ongoing COVID-19 pandemic, which has caused unprecedented social, economic, and political disruptions, is widely regarded as having a zoonotic origin. As such, the pandemic has extensively been framed as an environmental issue and has concretised the transnational effects of environmental degradation. Using the theoretical framework of neoliberal institutionalism, the article posits that the pandemic will reinvigorate environmental diplomacy between states in the post-pandemic world, particularly between ASEAN and the EU. The article furthermore analyses the concept of environmental diplomacy and historicises the relationship between these two intergovernmental organisations.

ABSTRACT Zika virus (ZIKV) is a member of the Flaviviridae family and is considered a major health threat causing cases of microcephaly in newborns and Guillain-Barré syndrome in adults. Here we targeted a transient deep and hydrophobic pocket of the super-open conformation of ZIKV NS2B-NS3 protease to overcome the limitations of the orthosteric inhibitors. After virtual docking screening of approximately 7 million compounds against the novel allosteric site we selected the top seven candidates and tested them in an enzymatic assay. Six out of seven top candidates selected by the docking screen inhibited ZIKV NS2B-NS3 protease proteolytic activity at low micromolar concentrations, as well as suppressing viral replication. These six compounds, targeting the selected protease pocket conserved in ZIKV as well as several other Flaviviruses, have opened an opportunity for a new kind of drug candidate that might be useful to treat several flaviviral infections.

The role of the human type I interferon (IFN-I) system in restricting Zika virus (ZIKV) is uncertain. Here, genetic and pharmacological ablation of IFN-I signalling enhanced ZIKV replication and cytopathicity in macrophages and microglia, key cells in ZIKV transmission and pathogenesis. Thus, despite the extensive IFN-I countermeasures employed by ZIKV, IFN-I dictates the outcome of infection in macrophages. Therapeutic manipulation of the IFN-I system may bring clinical benefit in ZIKV.

Medical inequity creates higher mortality rates among the vulnerable, particularly during public health crises. The key to solving this problem is to determine how to distribute medical resources equitably. The ethics community has discussed this issue at length. However, research on the equity of spatial distribution has been lacking. Recent studies have shown that public health crises can exacerbate the inequity of spatial allocation of urban medical resources. This paper explores the changes in medical preferences of Chinese residents during the COVID-19 epidemic and analyzes the spatial-temporal changes of equity in the spatial allocation of urban medical resources, to provide suggestions for equity. The results show that the spatial equity of medical resource allocation in Chinese cities fluctuated and decreased in time and space during the COVID-19 epidemic; this was caused by the gradual shift of people's medical preference to idle community hospitals. A small increase in patient flow can activate idle community medical resources and improve equity. However, an excessive influx of patients can then exceed capacity while at the same time causing high-grade hospitals to sit idle, making equity worse. In China's future healthcare reform, more attention should be paid to improving the carrying capacity of community hospitals.

Zika virus (ZIKV) is unique among mosquito-borne flaviviruses in that it is also vertically and sexually transmitted by humans. The male reproductive tract is thought to be a ZIKV reservoir; however, the reported magnitude and duration of viral persistence in male genital tissues varies widely in humans and non-human primate models. ZIKV tissue and cellular tropism and potential effects on male fertility also remain unclear. The objective of this study was to resolve these questions by analyzing archived genital tissues from 51 ZIKV-inoculated male macaques and correlating data on plasma viral kinetics, tissue tropism, and ZIKV-induced pathological changes in the reproductive tract. We hypothesized that ZIKV would persist in the male macaque genital tract for longer than there was detectable viremia, where it would localize to germ and epithelial cells and associate with lesions. We detected ZIKV RNA and infectious virus in testis, epididymis, seminal vesicle, and prostate gland. In contrast to prepubertal males, sexually mature macaques were significantly more likely to harbor persistent ZIKV RNA or infectious virus somewhere in the genital tract, with detection as late as 60 days post-inoculation. ZIKV RNA localized primarily to testicular stem cells/sperm precursors and epithelial cells, including Sertoli cells, epididymal duct epithelium, and glandular epithelia of the seminal vesicle and prostate gland. ZIKV infection was associated with microscopic evidence of inflammation in the epididymis and prostate gland of sexually mature males, which could have significant effects on male fertility. The findings from this study increase our understanding of persistent ZIKV infection which can inform risk of sexual transmission during assisted reproductive therapies as well as potential impacts on male fertility. Author Summary Zika virus (ZIKV) spread since 2015 led to establishment of urban epidemic cycles involving humans and Aedes mosquitoes. ZIKV is also sexually and vertically transmitted and causes congenital Zika syndrome. Together, these features show that ZIKV poses significant global public health risks. By virtue of similar reproductive anatomy and physiology to humans, macaques serve as a useful model for ZIKV infection. However, macaque studies to date have been limited by small sample size, typically 1 to 5 animals. Although mounting evidence identifies the male reproductive tract as a significant ZIKV reservoir, data regarding the duration of ZIKV persistence, potential for sexual transmission, and male genitourinary sequelae remain sparse. Here, we analyzed archived genital tissues from more than 50 ZIKV-inoculated male macaques. Our results show that ZIKV can persist in the male macaque reproductive tract after the resolution of viremia, with virus localization to sperm precursors and epithelial cells, and microscopic evidence of inflammation in the epididymis and prostate gland. Additionally, we show that freezing is not a viable method of destroying infectious ZIKV. Our findings help explain cases of sexual transmission of ZIKV in humans, which also carries a risk for transmission via assisted fertility procedures, even after resolution of detectable viremia.

Background: Paediatric emergency departments (PED) around the world have reported a large decrease in the utilisation of emergency care services amongst children during the COVID-19 pandemic. This phenomenon has been observed during previous epidemics but the extent, trends or causes are not clear. Objective: To assess the impact of epidemics and pandemics on the utilisation of paediatric emergency care services to provide health policy advice.Methods: Searches were conducted of Medline, EMBASE, CINAHL, Scopus, Web of Science, and the Cochrane Library for studies (until March 2021) that reported on changes in paediatric emergency care utilisation during epidemics. Two reviewers independently screened the results for inclusion. Data including study characteristics, PED visit data and other study findings were extracted. Quality assessment was completed using the National Institute for Health (NIH) quality assessment tool. Results: 131 articles were included within this review, 80% of which assessed the impact of COVID-19. Studies analysing COVID-19, SARS, MERS and Ebola found a reduction in PED visits whereas studies reporting on H1N1, Chikungunya Virus and an E coli outbreak found an increase in PED visits. Analysis suggested that the fear of the epidemic disease, from either contracting it or its potential adverse clinical outcomes, resulted in reductions and increases in PED utilisation, respectively. Conclusions: Epidemics can have very profound impacts on PED utilisation, the scale and direction of effect depend on both the epidemic disease, the public health measures enforced and how these influence parent/patient decision making. As public health messaging can impact on public behaviours, governing bodies and public health departments must be aware how fear of virus amongst the general public may influence their response to public health advice. Funding Information: None to declare. Declaration of Interests: No authors have conflicts of interest to disclose.

A mathematical model for Zika virus is proposed describing the spread of the disease in three interacting populations, namely, human, vector (mosquitoes) and non-human primate (monkeys) inhabiting forests area. Human movement between rural and forest areas has been also considered. It is assumed that Zika virus spreads within non-human primate population, which in turn acts as a reservoir of infection, and then transmitted to the human population through infected mosquitoes. The proposed model incorporates vertical transmission and direct transmission in all populations. The proposed model has been first normalized. The normalized model has been then fully analyzed both qualitatively and quantitatively to investigate the role of the interaction between forest mosquitoes and primates on the ZIKV transmission dynamics. The mathematical analysis includes positivity and boundedness of solutions, derivation of the basic reproduction number R 0 using the next generation matrix method, sensitivity analysis, existence and stability analysis of all equilibria and bifurcation analysis. Finally, numerical simulations have been carried out to illustrate the obtained theoretical results and to demonstrate the effect of some model parameters in the disease transmission dynamics. The results show that the interaction between forest mosquitoes and primates has a significant impact on the ZIKV transmission dynamics among human population through the fraction of susceptible moving to forest areas. Furthermore, the results highlight that the transmission probabilities are as important as the ratios of population size between vector population and human or primate populations in the disease transmission dynamics.

There are limited data on why the 2016 Zika outbreak in Miami-Dade County, Florida was confined to certain neighborhoods. In this research, Aedes aegypti , the primary vector of Zika virus, are studied to examine neighborhood-level differences in their population dynamics and underlying processes. Weekly mosquito data were acquired from the Miami-Dade County Mosquito Control Division from 2016 to 2020 from 172 traps deployed around Miami-Dade County. Using Random Forest, a machine learning method, predictive models of spatiotemporal dynamics of Ae. aegypti in response to meteorological conditions and neighborhood-specific socio-demographic and physical characteristics, such as land-use and land-cover type and income level, were created. The study area was divided into two groups: areas affected by local transmission of Zika during the 2016 outbreak and unaffected areas. Aedes aegypti populations in areas affected by Zika were more strongly influenced by 14- and 21-day lagged weather conditions. In the unaffected areas, mosquito populations were more strongly influenced by land-use and day-of-collection weather conditions. There are neighborhood-scale differences in Ae. aegypti population dynamics. These differences in turn influence vector-borne disease diffusion in a region. These results have implications for vector control experts to lead neighborhood-specific vector control strategies and for epidemiologists to guide vector-borne disease risk preparations, especially for containing the spread of vector-borne disease in response to ongoing climate change.

Background: Health care facilities are responsible for preventing and controlling diseases and must have sufficient resilience to deal with crises. Iranian health care facilities have faced challenges in managing COVID-19. The purpose of this study was to identify the challenges to the resilience of Iranian health care facilities during the COVID-19 pandemic and to provide appropriate solutions. Methods: : This qualitative study was conducted with a phenomenological approach and using semi-structured interviews with 59 managers, policy makers, health system experts, and faculty members. The participants were selected through snowball sampling. Thematic analysis was used to analyze the data. Results: : The resilience challenges of Iranian health care facilities were classified into eight groups: leadership and management; planning; organizational culture; organizational learning; employee management; customer management; resource management; and process management. The most important resilience challenges were: lack of an integrated management system; poor leadership; incompatibility of the management system and the network structure; lack of a national program; poor case detection program; lack of resources; inefficient information system; negative attitude of managers and employee; organizational inertia; failure to build on lessons learned from crises; lack of workforce preparedness; lack of community-based management; declining social capital; and lack of oversight. Managers must use community-based, evidence-based, and integrated management to build resilience against COVID-19, have sufficient knowledge and experience to organize operations, use appropriate and effective coordination models, develop a creative and participatory culture, reengineer structures and processes, and provide the necessary resources. Conclusion: Iranian health care facilities face challenges that prevent them from becoming resilient, responsive, and efficient in managing COVID-19. It is essential that policy makers and managers take the necessary steps to address these issues.

Human pluripotent stem cell (hPSC)-derived brain organoids offer an unprecedented opportunity for various applications as an in vitro model, such as modeling virus infection and drug screening. In this study, we present an experimental brain organoid platform for modeling infection with multiple viruses (e.g., influenza virus or enterovirus). Brain organoids challenged by influenza viruses (H1N1-WSN and H3N2-HKT68) had decreased overall organoid size, similar to ZIKA virus infection, while enteroviruses (EV68 and EV71) infected brain organoids displayed the opposite result. Then, we studied the molecular events in WSN-infected organoids, and we found that WSN could widely infect multiple cell types, and preferentially infected MAP2+ neurons compared to SOX2+ neural stem cells (NSCs) and GFAP+ astrocytes in brain organoids, and induced apoptosis of NSCs and neurons, but not astrocytes. The inflammatory responses in organoids observed to occur (Tumor necrosis factor alpha, interferon gamma, and interleukin 6) after WSN infection may further facilitate brain damage. Furthermore, transcriptional profiling revealed several upregulated genes ( CSAG3 and OAS2 ) and downregulated genes ( CDC20B, KCNJ13, OTX2-AS1, CROCC2 , and F5 ) after WSN infection for 24 hpi and 96 hpi, implicating antiviral drugs development responses to WSN. Finally, we explored neurotrophic factors (e.g., BDNF, GDNF, and NT3) and PYC-12 as antiviral and neuroprotective reagents, which could significantly suppress virus infection, apoptosis, and inflammatory responses. Collectively, we established a tractable experimental model system to investigate the impact and mechanism of virus infection on human brain development, and provide a platform for rapidly screening therapeutic compounds, advancing the development of antiviral strategies.

Background: The factors driving the late phase of COVID-19 are still poorly understood. However, autoimmunity is an evolving theme in COVID-19’s pathogenesis. Additionally, deregulation of human retroelements (RE) is found in many viral infections, and has also been reported in COVID-19. Methods The relationship of coronaviruses (CoV) to RE was explored by comparing CoV genomes to a comprehensive RE database. Next, the aligning results were matched to epitope signatures from severely vs. mildly affected COVID-19 patients. In addition, transcriptomes from healthy controls, COVID-19 patients as well as lung- and immune cells were investigated for changes in RE expression after SARS-CoV-2 infection. Results Unexpectedly, CoV – including SARS-CoV-2 – harbour many RE-identical sequences (up to 35 base pairs), and some of these sequences are part of SARS-CoV-2 epitopes associated to COVID-19 severity. Furthermore, RE are expressed in healthy controls and human cells and become deregulated after SARS-CoV-2 infection, showing mainly changes in long interspersed nuclear element (LINE1) expression, but also in endogenous retroviruses. Conclusion CoV and human RE share coding sequences, who are targeted by antibodies in COVID-19 and thus could induce an autoimmune loop by molecular mimicry. To the best of my knowledge these findings have never been reported before and should be explored further in CoV-related diseases.

Investigations of cellular responses to viral infection are commonly performed on mixed populations of infected and uninfected cells or using single-cell RNA sequencing, leading to inaccurate and low-resolution gene expression interpretations. Here, we performed deep polyA + transcriptome analyses and novel RNA profiling of SARS-CoV-2 infected lung epithelial cells, sorted based on the expression of the viral spike (S) protein. Infection caused a massive reduction in mRNAs and lncRNAs, including transcripts coding for antiviral factors, such as interferons (IFN). This absence of IFN signaling probably explained the poor transcriptomic response of bystander cells co-cultured with S + ones. NF-κB pathway and the inflammatory response escaped the global shutoff in S + cells. Functional investigations revealed the proviral function of the NF-κB pathway and the antiviral activity of CYLD, a negative regulator of the pathway. Thus, our transcriptomic analysis on sorted cells revealed additional genes that modulate SARS-CoV-2 replication in lung cells.

The Covid-19 pandemic, caused by SARS-CoV-2, resulted in more than 5 million deaths being one of the biggest challenges the world faces today. Here we present optimizations to all steps of an enzyme-linked immunosorbent assay (ELISA)-based test to detect IgG, IgA and IgM against the trimeric spike (S) protein, receptor binding domain (RBD), and N terminal domain of the nucleocapsid (N-NTD) protein of SARS-CoV-2. We discuss how to determine the specific thresholds for antibody positivity and its limitations according to the antigen used. We applied the assay in a cohort of 126 individuals from Rio de Janeiro, Brazil, consisting of 23 PCR-positive individuals; and 103 individuals without confirmed diagnosis for SARS-CoV-2 infection. To illustrate the differences in serological responses to vaccinal immunization, we applied the test in 18 individuals of our cohort before and after receive ChAdOx-1 nCoV-19 or CoronaVac vaccines. Taken together, our results show that the test can be customized at different stages depending on its application, enabling the user to analyze different cohorts, saving time, reagents, or samples. It also represents a valuable tool for elucidating the immunological consequences of new viral strains and for monitoring vaccination coverage and the duration of response to different immunization regimens.

Background: The role of ivermectin in the treatment of COVID-19 is still under debate, yet the drug has been widely used in some parts of the world, as shown by impressive market data and ivermectin-related adverse event reports. The available body of evidence may have changed over the last months, as studies have been retracted and "standards of care" (SOC) used in control groups have changed with rapidly evolving knowledge on COVID-19 rapidly. This review aims to summarize and critically appraise the evidence of randomized controlled trials (RCTs) of ivermectin, assessing clinical outcomes in COVID-19 patients. Methods: : RCTs evaluating the effects of ivermectin in adult patients with COVID-19 were searched through December 14, 2021, in four databases, L.OVE platform, clinical trial registries and pre-prints platforms. Primary endpoints included all-cause mortality and invasive ventilation requirement. Secondary endpoint was the occurrence of adverse events. Risk of bias was evaluated using the Cochrane Risk of Bias 2.0 tool. Random-effects were used to pool the risk ratios (RRs) of individual trials. The quality of evidence was evaluated using GRADE. Subgroup and sensitivity analysis were performed. The protocol was register in PROSPERO (CRD42021257471) Results: : Twenty-one RCTs fulfilled inclusion criteria (n=2592). Of those, 12 compared ivermectin with placebo and in seven ivermectin associated with SOC was compared to SOC. Most RCTs had some concerns or high risk of bias, mostly due to lack of concealment of the randomization sequence and allocation, lack of blinding and high number of missing cases. Ivermectin did not show an effect in reducing mortality (RR=0.76; 95%CI:0.44 to 1.32) or mechanical ventilation (RR=0.83; 95%CI:0.31 to 2.22) in COVID-19 patients. This effect was consistent when comparing ivermectin vs. placebo, and ivermectin associated with SOC vs. SOC, as well as in sensitivity analysis. Additionally, there was very low quality of evidence regarding adverse effects (RR=0.95; 95%CI: 0.86 to 1.04). Conclusions: : The evidence suggests that ivermectin does not reduce mortality risk and the risk of mechanical ventilation requirement. Although we did not observe an increase in the risk of adverse effects, the evidence is very uncertain regarding this endpoint. Funding: Research agencies FAPEMIG and CNPq.

Arboviruses are recognized by the World Health Organization (WHO) as a major public health problem, due to their growing territorial spread and the great need for preventive and control actions, which are increasingly complex. Among the arboviruses that present the greatest circulation is the Zika virus (ZIKV). Thus, this work aims to evaluate the expression of mTOR in tissues of females of the species Mesocricetus auratus infected with the Zika virus . The samples used in this study come from a larger project entitled “Experimental Zika virus infection in golden hamsters ( Mesocricetus auratus )” from the sexually transmitted group, previously approved by the Ethics Committee on Animal Use (CEUA) of Evandro Chagas Institute with registration number 24/2016. The samples are a total of 63 samples, divided between ZIKV-infected and non-infected animals. This study showed how Zika virus may be related to mTOR 1 and mTOR 2 expressions. The comparative results to viral load emphasize the correlation between the virus and mTOR. Such correlation is of importance to ZIKV, for protein regulation pathways and virus interference on those pathways may turn out to be a factor related to its pathogenic mechanism.

We posit that international business and the emergence and spread of communicable diseases are intrinsically connected. To support our arguments, we first start with a historical timeline that traces the connections between international business and communicable diseases back to the sixth century. Second, following the epidemiology of communicable diseases, we identify two crucial transitions related to international business: the emergence of epidemics within a host country and the shift from epidemics to global pandemics. Third, we highlight international business contextual factors (host country regulatory quality, urbanization, trade barriers, global migration) and multinationals’ activities (foreign direct investment, corporate political activity, global supply chain management, international travel) that could accelerate each transition. Finally, building on public health insights, we suggest research implications for business scholars on how to integrate human health challenges into their studies and practical implications for global managers on how to help prevent the emergence and spread of communicable diseases.

ABSTRACT Zika virus (ZIKV) infection in pregnancy can produce catastrophic teratogenic damage to the developing fetus including microcephaly and congenital Zika syndrome (CZS). We previously described fetal CNS pathology occurring by three weeks post-ZIKV infection in Olive baboons at mid-gestation, including neuroinflammation, loss of radial glia (RG), RG fibers, neuroprogenitor cells (NPCs) resulting in disrupted NPC migration. In the present study, we explored fetal brain pathologies at term gestation resulting from ZIKV infection during either first or second trimester in the Olive baboon. In all dams, viremia resolved after 7 days post infection (dpi). One first trimester infected dam aborted at 5 dpi. All dams developed IgM and IgG response to ZIKV with ZIKV IgG detected in fetal serum. Substantial placental pathology and inflammation was observed including disruption of syncytiotrophoblast layers, delayed villous maturation, partially or fully thrombosed vessels, calcium mineralization and fibrin deposits. In the uterus, ZIKV was detected in ¾ first trimester but not in second trimester infected dams. While ZIKV was not detected in any fetal tissue at term, all fetuses exhibited varying degrees of neuropathology. Fetal brains from ZIKV infected dams exhibited a range of gross brain pathologies including irregularities of the major gyri and sulci of the cerebral cortex and cerebellar pathology. Frontal cortices of ZIKV fetuses showed a general disorganization of the six-layered cortex with degree of disorganization varying among the fetuses from the two groups. Frontal cortices from first but not second trimester infections exhibited increased microglia and astrocyte numbers (white matter) in both trimester infections. In the cerebellum, increased microglia were observed in both first and second trimester infected fetuses and decreased oligodendrocyte precursor cell populations in the cerebellar white matter in first trimester infections. In general, our observations are in accordance with those described in human ZIKV infected fetuses.

Fast, highly sensitive and accurate techniques for monitoring their circulation is of key importance to limit virus spread and reduce social and economic burdens. This review provides a comprehensive overview of current techniques that have been developed for SARS-CoV-2 detection in different body fluids (e.g., blood, urine, feces, saliva, tears, and semen) and also extended to the newly discovered variants. Herein, we classified and comprehensively discussed the detection methods based on the biomarker measured (i.e., surface antigen, antibody, nucleic acid) and the measurement techniques (i.e. lateral flow immunoassay‒LFIA, enzyme-linked immunosorbent assay‒ELISA, biosensors, reverse transcriptase-polymerase chain reaction‒RT-PCR, and reverse transcription loop‐mediated isothermal amplification‒RT-LAMP, microarray Analysis, and clustered regularly interspaced short palindromic repeats‒CRISPR). Finally, we considered challenges in the diagnosis of newly emerging variants, virus-detection at the early-stage of infection, detection limit, selectivity, specificity, and comment on how these challenges can be tackled in the future.

SARS-CoV-2, the causative agent of COVID-19, emerged in late 2020. The highly contagious B.1.617.2 (Delta) Variant of Concern (VOC) was first identified in October 2020 in India and subsequently disseminated worldwide, later becoming the dominant lineage in the U.S. Despite considerable genomic analysis of SARS-CoV-2 in the U.S., several gaps in the understanding of the local dynamics during early introductions remain, which when elucidated could translate the results of viral genomic epidemiology to actionable mitigation efforts. Here, we explore the early emergence of the Delta variant in Florida, U.S. using phylogenetic analysis of representative Florida and globally sampled genomes. We find multiple independent introductions into Florida primarily from North America and Europe, with a minority originating from Asia. These introductions lead to three distinct clades that demonstrated varying relative rates of transmission and possessed five distinct substitutions that were 3-21 times more prevalent in the Florida sample as compared to the global sample. Our results underscore the benefits of routine viral genomic surveillance to monitor epidemic spread and support the need for more comprehensive genomic epidemiology studies of emerging variants. In addition, we provide a model of epidemic spread of newly emerging VOCs that can inform future public health responses.

ABSTRACT Zika virus (ZIKV) is unusual among flaviviruses in its ability to spread between humans through sexual contact, as well as by mosquitoes. Sexual transmission has the potential to change the epidemiology and geographic range of ZIKV compared to mosquito-borne transmission and potentially could produce distinct clinical manifestations, so it is important to understand the host mechanisms that control susceptibility to sexually transmitted ZIKV. ZIKV replicates poorly in wild-type mice following subcutaneous inoculation, so most ZIKV pathogenesis studies use mice lacking IFN-αβ signaling (e.g. Ifnar1 -/- ). However, we found that wild-type mice support ZIKV replication following intravaginal infection, although the infection remained localized to the lower female reproductive tract. Vaginal replication was not a unique property of ZIKV, as other flaviviruses that generally are restricted in wild-type mice also were able to replicate in the vagina. Vaginal ZIKV infection required a high-progesterone state (pregnancy or pre-treatment with depot medroxyprogesterone acetate (DMPA)), identifying a key role for hormonal status in susceptibility to vaginal infection. Progesterone-mediated susceptibility did not appear to result from a compromised epithelial barrier, blunted antiviral gene induction, or changes in vaginal leukocyte populations, leaving open the mechanism by which progesterone confers susceptibility to vaginal ZIKV infection. Progesterone treatment is a key component of mouse vaginal infection models for herpes simplex virus and Chlamydia , but the mechanisms by which DMPA increases susceptibility to those pathogens also remain poorly defined. Understanding how progesterone mediates susceptibility to ZIKV vaginal infection may provide insights into host mechanisms influencing susceptibility to diverse sexually transmitted pathogens. IMPORTANCE Zika virus (ZIKV) is transmitted by mosquitoes, similarly to other flaviviruses. However, ZIKV is unusual in its ability also to spread through sexual transmission. We found that ZIKV was able to replicate in the vaginas of wild-type mice, even though these mice do not support ZIKV replication by other routes, suggesting that the vagina is particularly susceptible to ZIKV infection. Vaginal susceptibility was dependent on a high progesterone state, which is a common feature of mouse vaginal infection models for other pathogens, through mechanisms that have remained poorly defined. Understanding how progesterone mediates susceptibility to ZIKV vaginal infection may provide insights into host mechanisms that influence susceptibility to diverse sexually transmitted pathogens.

Arboviruses such as flaviviruses and alphaviruses cause a significant human healthcare burden on the global scale. Transmission of these viruses occurs during human blood feeding at the mosquito-skin interface. Not only do pathogen immune evasion strategies influence the initial infection and replication of pathogens delivered, but arthropod salivary factors also influence transmission foci. In-vitro cell cultures do not provide an adequate environment to study complex interactions between viral, mosquito, and host factors. To address this need for a whole tissue system, we describe a proof-of-concept model for arbovirus infection using adult human skin ex vivo with Zika virus (flavivirus) and Mayaro virus (alphavirus). Replication of these viruses in human skin was observed up to 4 days post-infection. Egressed viruses could be detected in the culture media as well. Antiviral and pro-inflammatory genes, including chemoattractant chemokines, were expressed in infected tissue. Immunohistochemical analysis showed the presence of virus in the skin tissue at 4 days post-infection. This model will be useful to further investigate: 1) the immediate molecular mechanisms of arbovirus infection in human skin, and 2) the influence of arthropod salivary molecules during initial infection of arboviruses in a more physiologically relevant system.

The novel coronavirus disease 2019 (COVID-19) pandemic has brought major challenges to the management of municipal solid wastes (MSWs), which may present an under-investigated route of transmission for SARS-CoV-2 and other infectious agents. Food wastes, personal care products (e.g., toothbrushes, first aids, feminine hygiene products), disposable products (e.g., tissues and wipes, face masks, plastic utensils), and other personal items (e.g., pillows, napkins, razor blades) are easily contaminated with human biological matter that carries infectious agents from infected households. The management of MSWs involves complex logistics with a range of facilities and personnel involved, from their collection, bulk transport, handling, and final disposal. The process often requires manual operations with risks of inhalation of virus-laden aerosols or inadvertent contact with virus-contaminated objects or surfaces. Further, unrestrained access to waste bins in public settings or open landfills can expose certain individuals (e.g., waste pickers, custodial staff, machinery operators) and mechanical vectors (e.g., animals, insects) to SARS-CoV-2 and other infectious agents carried on MSWs. In developing communities, unsanitary practices of MSW handling and disposal such as fly-tipping, waste picking, and unprotected workers with informal employment can exacerbate the risk of MSW-mediated transmission of SARS-CoV-2 and other pathogens among MSW workers and residents near waste collection and disposal sites. This review scrutinizes the practices of MSW management in the Covid-19 context and articulates the key risk factors by assessing current evidence, policies, gaps, and voluntary actions taken on MSW handling and disposal in the pandemic. We highlight the main knowledge gaps on MSW-mediated transmission of SARS-CoV-2 and other infectious agents and propose several risk mitigation strategies and research priorities to alleviate the risk for humans and vectors exposed to MSWs and to understand the role of MSWs in spreading infectious agents including novel pathogens to humans and animal hosts.

Summary The COVID-19 pandemic has highlighted the need for novel antivirals for pandemic management and preparedness. Targeting host processes that are co-opted by viruses is an attractive strategy for developing antivirals with a high resistance barrier. Picolinic acid (PA) is a byproduct of tryptophan metabolism, endogenously produced in humans and other mammals. Here we report broad-spectrum antiviral effects of PA against enveloped viruses, including Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), Influenza A virus (IAV), Flaviviruses, Herpes Simplex Virus, and Human Parainfluenza Virus. We further demonstrate using animal models that PA is effective against SARS-CoV-2 and IAV, especially as an oral prophylactic. The mode of action studies revealed that PA inhibits viral entry of enveloped viruses, primarily by interfering with viral-cellular membrane fusion, inhibiting virus-mediated syncytia formation, and dysregulating cellular endocytosis. Overall, our data establish PA as a broad-spectrum antiviral agent, with promising preclinical efficacy against pandemic viruses SARS-CoV-2 and IAV.

The novel COVID-19 global pandemic has raised, among many others, major concerns regarding the impact of infection during pregnancy. At the time of this writing, vertical SARS-COV-2 transmission in pregnancy has been considered probable, but is yet to be confirmed. According to the published reports of infants born to COVID-19-affected mothers, as well as the anecdotal experience of current practices worldwide, it appears that investigations regarding the possibility of SARS-COV-2 vertical transmission in pregnancy have so far been based, to a large extent, on PCR testing of neonatal pharyngeal swab samples. Given that the hypothetical route of vertical transmission for SARS-COV-2 is less likely to involve the upper respiratory tract, contrary to what happens after birth, it would be advisable to include appropriate biological samples, such as cord blood, placenta, amniotic fluid and neonatal blood, along with the pharyngeal samples, in order to contribute significantly to such investigations. Revision and enhancement of the so far prevailing practices appear even more important, as the impact of SARS-COV-2 infection occurring early in pregnancy is still unknown, this challenge remaining to be confronted in the immediate future.