Going Viral 2019: Zika, Chikungunya, and Dengue

Fever and Rash

Infectious causes of fever and rash pose a diagnostic challenge for the emergency provider. It is often difficult to discern rashes associated with rapidly progressive and life-threatening infections from benign exanthems, which comprise the majority of rashes seen in the emergency department. Physicians must also consider serious noninfectious causes of fever and rash. A correct diagnosis depends on an exhaustive history and head-to-toe skin examination as most emergent causes of fever and rash remain clinical diagnoses. A provisional diagnosis and immediate treatment with antimicrobials and supportive care are usually required prior to the return of confirmatory laboratory testing.

Environmental factors and their impact on chronic pain development and maintenance

It is more than recognized and accepted that the environment affects the physiological responses of all living things, from bacteria to superior vertebrates, constituting an important factor in the evolution of all species. Environmental influences range from natural processes such as sunlight, seasons of the year, and rest to complex processes like stress and other mood disorders, infections, and air pollution, being all of them influenced by how each creature deals with them. In this chapter, it will be discussed how some of the environmental elements affect directly or indirectly neuropathic pain, a type of chronic pain caused by a lesion or disease of the somatosensory nervous system. For that, it was considered the edge of knowledge in translational research, thus including data from human and experimental animals as well as the applicability of such findings.

Chikungunya in Zhejiang Province, Southeast China

Background

Chikungunya is emerging and reemerging word-widely in the past decades. It is non-endemic in Zhejiang Province, Southeast China. Aedes albopictus, one of major vectors of chikungunya, is widely-distribution in Zhejiang, and autochthonous transmission is possible after introducing chikungunya virus.

Methods

Retrospectively collected the epidemiological, clinical and genetic data of chikungunya and conducted the descriptive analysis and gene sequence analysis.

Results

From 2008 to 2022, 29 chikungunya cases, including 26 overseas imported and 3 local cases, were reported and no cases died of chikungunya. More than half of the imported cases (53.85%) were from Southeast Asia. Seasonal peak of the imported cases was noted between August and September, and 42.31% cases onset in those 2 months. Eight prefecture-level cities and 16 counties reported cases during the study period, with Jinghua (27.59%) and Hangzhou (24.14%) reporting the largest number of cases. The 3 local cases were all reported in Qujiang, Quzhou in 2017. For imported cases, the male-female gender ratio was 2.71:1, 20-30 years old cases (46.15%) and commercial service (42.31%) accounted for the highest proportion. Clinically, fever (100%), fatigue (94.44%), arthralgia (79.17%), headache (71.43%) and erythra (65.22%) were the most common reported symptoms. Eight whole-genome sequences were obtained and belonged to East/Central/South African (ECSA) or Asian genotype.

Conclusions

With the change of immigration policy, the surveillance of chikungunya should be strengthened and the ability of the case discovery and diagnosis should be improved in Zhejiang in the post-COVID-19 era.

Determining Perceived Self-Efficacy for Preventing Dengue Fever in Two Climatically Diverse Mexican States: A Cross-Sectional Study

Knowledge of dengue fever and perceived self-efficacy toward dengue prevention does not necessarily translate to the uptake of mosquito control measures. Understanding how these factors (knowledge and self-efficacy) influence mosquito control measures in Mexico is limited. Our study sought to bridge this knowledge gap by assessing individual-level variables that affect the use of mosquito control measures. A cross-sectional survey with 623 participants was administered online in Mexico from April to July 2021. Multiple linear regression and multiple logistic regression models were used to explore factors that predicted mosquito control scale and odds of taking measures to control mosquitoes in the previous year, respectively. Self-efficacy (β = 0.323, p-value = < 0.0001) and knowledge about dengue reduction scale (β = 0.316, p-value =< 0.0001) were the most important predictors of mosquito control scale. The linear regression model explained 24.9% of the mosquito control scale variance. Increasing age (OR = 1.064, p-value =< 0.0001) and self-efficacy (OR = 1.020, p-value = 0.0024) were both associated with an increase in the odds of taking measures against mosquitoes in the previous year. There is a potential to increase mosquito control awareness and practices through the increase in knowledge about mosquito reduction and self-efficacy in Mexico.

A flavivirus-inducible gene expression system that modulates broad-spectrum antiviral activity against dengue and Zika viruses

Incidence of dengue virus (DENV) and Zika virus (ZIKV), two mosquito-borne flaviviruses, is increasing in large parts of the world. Vaccination and medication for these diseases are unsatisfactory. Here, we developed a novel antiviral approach, using a virus-inducible gene expression system, to block virus replication and transmission. Constructs containing the smallest replication units of dengue virus serotype 2 (DENV2) with negative-stranded DENV2 artificial genomes and genes of interest were established in an Aedes aegypti cell line, resulting in expression of target genes after DENV2 infection. Green fluorescent protein (GFP) assays confirmed the system was virus-inducible. When we used one of two apoptosis-related genes, A. aegypti michelob_x (AaMx) and inhibitor of apoptosis (IAP)-antagonist michelob_x-like protein (AaIMP) instead of GFP, the production of viral RNA and proteins were inhibited for all five viruses tested (DENV1-4 and ZIKV), and effector caspase activity was induced. The system thus inhibited the production of infectious virus particles in vitro, and in mosquitoes it did so after DENV2 infection. This is a novel broad-spectrum antiviral approach using a flavivirus-inducible gene-expression system, which could lead to new avenues for mosquito-borne disease control.

Neglected tropical rheumatic diseases

The complexities of dealing with rheumatic diseases in tropical countries are diverse and likely due to limited health care infrastructure, lack of diagnostic and therapeutic facilities, impact of dominant prevailing diseases, and the challenges of differentiating from infectious and non-infectious disease mimics. Several tropical diseases present with musculoskeletal and rheumatic manifestations and often pose a diagnostic dilemma to rheumatologists. The diagnosis is often delayed or the disease is misdiagnosed, leading to poor patient outcomes. Endemic tropical diseases like tuberculosis and leprosy have myriad rheumatic presentations and remain important differentials to consider in patients with rheumatic manifestations. Infection with human immunodeficiency virus is a great masquerade and can mimic manifestations of multiple diseases. The role of viral infections in triggering and perpetuating autoimmunity is well known and chikungunya arthritis is a classic example of the same. This review highlights the rheumatic manifestations of tropical diseases and aims to create awareness among the caregivers. Key Points • It is crucial to be aware and identify infectious diseases presenting with rheumatic manifestations in the tropics. • Presentations akin to classic rheumatic syndromes such as rheumatoid arthritis, spondyloarthritis, systemic lupus erythematosus and vasculitis are common.

Seroprevalence and associated risk factors of chikungunya, dengue, and Zika in eight districts in Tanzania

BACKGROUND

This study was conducted to determine the seroprevalence and risk factors of chikungunya (CHIKV), dengue (DENV), and Zika (ZIKV) viruses in Tanzania.

METHODS

The study covered the districts of Buhigwe, Kalambo, Kilindi, Kinondoni, Kondoa, Kyela, Mvomero, and Ukerewe in Tanzania. Blood samples were collected from individuals recruited from households and healthcare facilities. An ELISA was used to screen for immunoglobulin G antibodies against CHIKV, DENV, and ZIKV.

RESULTS

A total of 1818 participants (median age 34 years) were recruited. The overall CHIKV, DENV, and ZIKV seroprevalence rates were 28.0%, 16.1%, and 6.8%, respectively. CHIKV prevalence was highest in Buhigwe (46.8%), DENV in Kinondoni (43.8%), and ZIKV in Ukerewe (10.6%) and Mvomero (10.6%). Increasing age and frequent mosquito bites were significantly associated with CHIKV and DENV seropositivity (P < 0.05). Having piped water or the presence of stagnant water around the home (P < 0.01) were associated with higher odds of DENV seropositivity. Fever was significantly associated with increased odds of CHIKV seropositivity (P < 0.001). Visiting mines had higher odds of ZIKV seropositivity (P < 0.05).

CONCLUSIONS

These findings indicate that DENV, CHIKV, and ZIKV are circulating in diverse ecological zones of Tanzania. There is a need to strengthen the control of mosquito-borne viral diseases in Tanzania.

Infectious exanthemas in childhood

Most childhood exanthemas are harmless. However, recognizing serious diseases with life-threatening complications at an early stage is important for the timely initiation of adequate therapy. This requires knowledge of the specific patterns of the exanthema, obtained from the medical history and the clinic, including the patient's general condition and physical examination. In unclear cases, additional diagnostic measures are undertaken, such as blood tests and smears (cutaneous, mucocutaneous). Viruses are the most common cause of childhood exanthemas. New variants of infectious agents, improved diagnostics and stays in tropical and subtropical countries have expanded the spectrum of infectious exanthemas.

Whole-exome sequencing reveals insights into genetic susceptibility to Congenital Zika Syndrome

Congenital Zika Syndrome (CZS) is a critical illness with a wide range of severity caused by Zika virus (ZIKV) infection during pregnancy. Life-threatening neurodevelopmental dysfunctions are among the most common phenotypes observed in affected newborns. Risk factors that contribute to susceptibility and response to ZIKV infection may be related to the virus itself, the environment, and maternal genetic background. Nevertheless, the newborn’s genetic contribution to the critical illness is still not elucidated. Here, we aimed to identify possible genetic variants as well as relevant biological pathways that might be associated with CZS phenotypes. For this purpose, we performed a whole-exome sequencing in 40 children born to women with confirmed exposure to ZIKV during pregnancy. We investigated the occurrence of rare harmful single-nucleotide variants (SNVs) possibly associated with inborn errors in genes ontologically related to CZS phenotypes. Moreover, an exome-wide association analysis was also performed using a case-control design (29 CZS cases and 11 controls), for both common and rare variants. Five out of the 29 CZS patients harbored known pathogenic variants likely to contribute to mild to severe manifestations observed. Approximately, 30% of affected individuals carried at least one pathogenic or likely pathogenic SNV in genes candidates to play a role in CZS. Our common variant association analysis detected a suggestive protective effect of the rs2076469 in DISP3 gene (p-value: 1.39 x 10⁻⁵). The IL12RB2 gene (p-value: 2.18x10^-11) also showed an unusual distribution of nonsynonymous rare SNVs in control samples. Finally, genes harboring harmful variants are involved in processes related to CZS phenotypes such as neurological development and immunity. Therefore, both rare and common variations may be likely to contribute as the underlying genetic cause of CZS susceptibility. The variations and pathways identified in this study may also have implications for the development of therapeutic strategies in the future.

Since the beginning of Zika virus outbreak in Brazil, five years ago, we still don’t understand the genetic factors associated with the small number of babies born with Congenital Zika Syndrome (CZS). Here, we focused on the host genetic susceptibility by studying the whole-exome of the CZS affected (n = 29) and healthy (n = 11) neonates, both born to ZIKV infected women from Brazil. We applied two strategies: 1) Determine whether cases individuals have pathogenic or harmful variants that explain the CZS outcomes (i.e. microcephaly) independently of ZIKV infection or not, 2) Exploring the common and rare variants association with CZS. We found that common and rare variants in genes like DISP3 and IL12RB2 could explain some level of the susceptibility to CZS. Moreover, by considering these and other candidate genes, we observed an over-representation of Gene Ontology terms related to neurological system, metabolism and microtubule-cytoskeleton organization.

Drug Repurposing: A Strategy for Discovering Inhibitors against Emerging Viral Infections

BACKGROUND

Viral diseases are responsible for several deaths around the world. Over the past few years, the world has seen several outbreaks caused by viral diseases that, for a long time, seemed to possess no risk. These are diseases that have been forgotten for a long time and, until nowadays, there are no approved drugs or vaccines, leading the pharmaceutical industry and several research groups to run out of time in the search for new pharmacological treatments or prevention methods. In this context, drug repurposing proves to be a fast and economically viable technique, considering the fact that it uses drugs that have a well-established safety profile. Thus, in this review, we present the main advances in drug repurposing and their benefit for searching new treatments against emerging viral diseases.

METHODS

We conducted a search in the bibliographic databases (Science Direct, Bentham Science, PubMed, Springer, ACS Publisher, Wiley, and NIH's COVID-19 Portfolio) using the keywords "drug repurposing", "emerging viral infections" and each of the diseases reported here (CoV; ZIKV; DENV; CHIKV; EBOV and MARV) as an inclusion/exclusion criterion. A subjective analysis was performed regarding the quality of the works for inclusion in this manuscript. Thus, the selected works were those that presented drugs repositioned against the emerging viral diseases presented here by means of computational, high-throughput screening or phenotype-based strategies, with no time limit and of relevant scientific value.

RESULTS

291 papers were selected, 24 of which were CHIKV; 52 for ZIKV; 43 for DENV; 35 for EBOV; 10 for MARV; and 56 for CoV and the rest (72 papers) related to the drugs repurposing and emerging viral diseases. Among CoV-related articles, most were published in 2020 (31 papers), updating the current topic. Besides, between the years 2003 - 2005, 10 articles were created, and from 2011 - 2015, there were 7 articles, portraying the outbreaks that occurred at that time. For ZIKV, similar to CoV, most publications were during the period of outbreaks between the years 2016 - 2017 (23 articles). Similarly, most CHIKV (13 papers) and DENV (14 papers) publications occur at the same time interval. For EBOV (13 papers) and MARV (4 papers), they were between the years 2015 - 2016. Through this review, several drugs were highlighted that can be evolved in vivo and clinical trials as possible used against these pathogens showed that remdesivir represent potential treatments against CoV. Furthermore, ribavirin may also be a potential treatment against CHIKV; sofosbuvir against ZIKV; celgosivir against DENV, and favipiravir against EBOV and MARV, representing new hopes against these pathogens.

CONCLUSION

The conclusions of this review manuscript show the potential of the drug repurposing strategy in the discovery of new pharmaceutical products, as from this approach, drugs could be used against emerging viral diseases. Thus, this strategy deserves more attention among research groups and is a promising approach to the discovery of new drugs against emerging viral diseases and also other diseases.

An updated RT-qPCR assay for the simultaneous detection and quantification of chikungunya, dengue and zika viruses

The real-time reverse transcription-polymerase chain reaction (real-time RT-qPCR) has become a leading technique for the detection and quantification of arboviruses, including Chikungunya, Dengue, and Zika viruses. In this study, an updated real-time RT-qPCR assay was designed and evaluated together with a synthetic positive-control chimeric RNA for the simultaneous detection and quantification of Chikungunya, Dengue, and Zika viruses. Amplification assays were performed to verify the construct integrity and optimal reaction/thermal cycling conditions. The analytical sensitivity of the assay was determined for each virus in single and multiplex reactions, as well as the performance in the detection and viral load quantification of experimental samples. The real-time RT-qPCR assay presented here allowed for the simultaneous detection and quantification of Chikungunya, Dengue, and Zika viruses and could be applied in several studies where the accurate quantification of viral genomes is required.

Hilaire M. Serological Evidence of Human Orthohantavirus Infections in Barbados, 2008 to 2016

Background: Hantavirus pulmonary syndrome (HPS) is well-known in South and North America; however, not enough data exist for the Caribbean. The first report of clinical orthohantavirus infection was obtained in Barbados, but no other evidence of clinical orthohantavirus infections among adults in the Caribbean has been documented. Methods: Using enzyme linked immunosorbent assay (ELISA) tests followed by confirmatory testing with immunofluorescent assays (IFA), immunochromatographic (ICG) tests, and pseudotype focus reduction neutralization tests (pFRNT), we retrospectively and prospectively detected orthohantavirus-specific antibodies among patients with febrile illness in Barbados. Results: The orthohantavirus prevalence rate varied from 5.8 to 102.6 cases per 100,000 persons among febrile patients who sought medical attention annually between 2008 and 2016. Two major orthohantavirus epidemics occurred in Barbados during 2010 and 2016. Peak orthohantavis infections were observed observed during the rainy season (August) and prevalence rates were significantly higher in females than males and in patients from urban parishes than rural parishes. Conclusions: Orthohantavirus infections are still occurring in Barbados and in some patients along with multiple pathogen infections (CHIKV, ZIKV, DENV and Leptospira). Orthohantavirus infections are more prevalent during periods of high rainfall (rainy season) with peak transmission in August; females are more likely to be infected than males and infections are more likely among patients from urban rather than rural parishes in Barbados.

Arbovirus Rash in the Febrile Returning Traveler as a Diagnostic Clue

Purpose of Review

This review aims to describe briefly the general information of arboviruses dengue, Zika, and chikungunya infections and emphasize the clinical manifestations of each, to help identify and make a quick diagnosis of each.

Recent Findings

The most relevant advances in the study of these arboviruses' infections have been in the epidemiological distribution, mainly due to international travel, migration, and climate change; in the clinical manifestations of these diseases, the development of clinical decision-making software, which can help improve the management and outcomes of these patients; and in the prevention of this disease.

Summary

Although arboviruses infections constitute a clinical challenge for the attending physician in the scope of a febrile returning traveler, a thorough clinical history and exam can help to aid diagnostic reasoning. The characteristics of the rash are a very helpful clue in the evaluation of these patients. Currently, there are clinical decision aid tools that help to get the diagnosis more quickly.

Asynchronicity of endemic and emerging mosquito-borne disease outbreaks in the Dominican Republic

Mosquito-borne viruses threaten the Caribbean due to the region's tropical climate and seasonal reception of international tourists. Outbreaks of chikungunya and Zika have demonstrated the rapidity with which these viruses can spread. Concurrently, dengue fever cases have climbed over the past decade. Sustainable disease control measures are urgently needed to quell virus transmission and prevent future outbreaks. Here, to improve upon current control methods, we analyze temporal and spatial patterns of chikungunya, Zika, and dengue outbreaks reported in the Dominican Republic between 2012 and 2018. The viruses that cause these outbreaks are transmitted by Aedes mosquitoes, which are sensitive to seasonal climatological variability. We evaluate whether climate and the spatio-temporal dynamics of dengue outbreaks could explain patterns of emerging disease outbreaks. We find that emerging disease outbreaks were robust to the climatological and spatio-temporal constraints defining seasonal dengue outbreak dynamics, indicating that constant surveillance is required to prevent future health crises.

Co-infection of Dengue, Zika and Chikungunya in a group of pregnant women from Tuxtla Gutiérrez, Chiapas: Preliminary data. 2019

INTRODUCTION

Dengue, Zika and Chikungunya are RNA Arboviruses present in some areas of Mexico, mainly in the endemic state of Chiapas that is characterized by presence of the vector that transmit them and an ecology that favors high transmission. According to the national epidemiological surveillance system, Dengue has intensified since 2018 and outbreaks continue in various states while for Zika and Chikungunya a decrease in cases has been reported in recent years. The main objective of this study was to determine the incidence of Dengue, Zika and Chikungunya infections during pregnancy in the state of Chiapas.

PRINCIPAL FINDINGS

The presence of previous and current infections and coinfections diagnosed by molecular (RT-PCR) and immunological (ELISA for IgG determination) techniques indicates a wide circulation of viruses in asymptomatic people, specifically in pregnant women showing that silent infections in dry season contributes to the preservation of viruses.

CONCLUSIONS

From 136 studied samples, 27.7% tested positive for DENV, 8% for ZIKV and 24.1% for CHIKV by RTPCR and the values of IgG in sera show that 83.9% were positive for IgG antibodies against DENV, 65% against ZIKV and 59.1% against CHIKV. Results demonstrated presence of ZIKV and CHIKV, not detected by the epidemiological surveillance system, so the importance of establishing proactive epidemiological systems more strict, especially because these infections in pregnant women can cause severe health problems for newborn children.

SARS-CoV-2 and arbovirus infection: a rapid systematic review

BACKGROUND

The numbers of cases of arboviral diseases have increased in tropical and subtropical regions while the coronavirus disease (COVID-19) pandemic overwhelms healthcare systems worldwide. The clinical manifestations of arboviral diseases, especially dengue fever, can be very similar to COVID-19, and misdiagnoses are still a reality. In the meantime, outcomes for patients and healthcare systems in situations of possible syndemic have not yet been clarified.

OBJECTIVE

We set out to conduct a systematic review to understand and summarize the evidence relating to clinical manifestations, disease severity and prognoses among patients coinfected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and arboviruses.

METHODS

We conducted a rapid systematic review with meta-analysis, on prospective and retrospective cohorts, case-control studies and case series of patients with confirmed diagnoses of SARS-CoV-2 and arboviral infection. We followed the Cochrane Handbook recommendations. We searched EMBASE, MEDLINE, Cochrane Library, LILACS, Scopus and Web of Science to identify published, ongoing and unpublished studies. We planned to extract data and assess the risk of bias and the certainty of evidence of the studies included, using the Quality in Prognosis Studies tool and the Grading of Recommendations Assessment.

RESULTS

We were able to retrieve 2,407 citations using the search strategy, but none of the studies fulfilled the inclusion criteria.

CONCLUSION

The clinical presentations, disease severity and prognoses of patients coinfected with SARS-CoV-2 and arboviruses remain unclear. Further prospective studies are necessary in order to provide useful information for clinical decision-making processes.

PROTOCOL REGISTRATION NUMBER IN THE PROSPERO DATABASE

CRD42020183460.

Extra-respiratory manifestations of COVID-19

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Most COVID-19 patients show fever and respiratory symptoms, however they may present extra-respiratory manifestations.

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Cardiac, gastrointestinal, hepatic, renal, neurologic, olfactory, gustatory, ocular, cutaneous and haematologic symptoms.

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Extra-respiratory symptoms/signs may represent the initial presentation of SARS-CoV-2 infection.

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This review is aimed to help clinicians better understand the range of clinical presentations associated with SARS-CoV-2.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global health threat. Although most patients with COVID-19 manifest fever and respiratory tract symptoms, SARS-CoV-2 infection may also involve other organs/systems and present with extra-respiratory manifestations, including cardiac, gastrointestinal, hepatic, renal, neurological, olfactory, gustatory, ocular, cutaneous and haematological symptoms. Occasionally, these extra-respiratory symptoms/signs represent the initial presentation of SARS-CoV-2 infection, prior to fever or respiratory manifestations. Therefore, this comprehensive review of the extra-respiratory manifestations of COVID-19 is intended to help clinicians better understand the range of clinical presentations associated with SARS-CoV-2 infection, allowing the consideration of COVID-19 in differential diagnoses. A screening test for SARS-CoV-2 should be performed when patients have these extra-respiratory manifestations. In addition, clinicians should be alerted to the adverse effects of anti-SARS-CoV-2 agents that can mimic the extra-respiratory manifestations of COVID-19. Moreover, some extra-respiratory manifestations, such as ocular and gastrointestinal involvement, may be caused by direct invasion of SARS-CoV-2. Therefore, protective measures should be taken while managing the associated clinical specimens. Finally, several extra-respiratory manifestations, such as cardiac involvement, acute kidney injury, coagulation disorders and thrombotic complications, could be associated with a poor prognosis.

The prevention of arboviral diseases using mobile devices: a preliminary study of the attitudes and behaviour change produced by educational interventions

OBJECTIVES

In Brazil, the National Policy for Dengue Control seeks to incorporate the lessons of national and international experience in dengue control, emphasising the need for health education activities. The objective of this study was to evaluate and compare knowledge, attitudes and behaviours related to the prevention of arboviruses before and after a two-month educational intervention using a learning platform on mobile devices.

METHODS

This quasi-experimental study corresponds to the first phase of the project 'Impact of mobile learning in the prevention and management of complications caused by arboviruses (Zika, Dengue, Chikungunya) - ZIKAMOB', sponsored as part of the British Council Newton Fund.

RESULTS

Thirty of the 93 participants were first-year undergraduate university students (36.7% male), and 63 were police officers (84.1% male). The pattern of attitudes and behaviour was very similar in both groups before the intervention. The students changed their attitudes and behaviour (P = 0.032) in relation to their engagements in actions for the prevention of arboviral diseases and several other activities related to house inspections and precautions with water tanks (P < 0.01). However, recycling and surveillance activities were not as effective in changing behaviour. Female participants showed more motivation to participate in preventive activities, but living alone and working were barriers to participation. Individuals who already perform selective waste collection and are cultivating gardens demonstrated both a positive attitude and a positive behaviour towards actions for the prevention of arboviral diseases.

CONCLUSION

Mobile learning and behaviour change theories might be successful as the basis for school-based and community-based interventions to avoid arboviruses. These outcomes need to be confirmed in broader future studies.

Drugs for the Treatment of Zika Virus Infection

Zika virus is an emerging flavivirus that causes the neurodevelopmental congenital Zika syndrome and that has been linked to the neuroinflammatory Guillain-Barré syndrome. The absence of a vaccine or a clinically approved drug to treat the disease combined with the likelihood that another outbreak will occur in the future defines an unmet medical need. Several promising drug candidate molecules have been reported via repurposing studies, high-throughput compound library screening, and de novo design in the short span of a few years. Intense research activity in this area has occurred in response to the World Health Organization declaration of a Public Health Emergency of International Concern on February 1, 2016. In this Perspective, the authors review the emergence of Zika virus, the biology of its replication, targets for therapeutic intervention, target product profile, and current drug development initiatives.

Aedes aegypti larvae treated with spinosad produce adults with damaged midgut and reduced fecundity

The mosquito Aedes aegypti is the main vector of Dengue, Chikungunya, Zika, and yellow fever viruses, which are responsible for high human morbidity and mortality. The fight against these pathogens is mainly based on the control of the insect vector with the use of insecticides. Among insecticides, spinosad bioinsecticide is efficient against A. aegypti larvae and may be an alternative for vector control. Here, we investigate the sublethal effects of spinosad during midgut metamorphosis of A. aegypti females and its cumulative effects on blood acquisition capacity and fecundity in adults. We studied the midgut because it is an important model organ directly related to blood acquisition and digestion. Treatment of larvae with spinosad induced oxidative stress, apoptosis, and damage to the midgut cells at all stages of development and in adults. There was a reduction in the number of proliferating cells and the number of enteroendocrine cells in treated individuals. In addition, damage caused by spinosad led to a reduction in oviposition and egg viability of A. aegypti females. Finally, the exposure of mosquito larvae to sublethal concentrations of spinosad interfered with the development of the midgut, arresting the blood digestion and reproduction of adult females with blood digestion and reproduction difficulties.

Autophagy in Zika Virus Infection: A Possible Therapeutic Target to Counteract Viral Replication

Zika virus (ZIKV) still constitutes a public health concern, however, no vaccines or therapies are currently approved for treatment. A fundamental process involved in ZIKV infection is autophagy, a cellular catabolic pathway delivering cytoplasmic cargo to the lysosome for degradation—considered as a primordial form of innate immunity against invading microorganisms. ZIKV is thought to inhibit the Akt-mTOR signaling pathway, which causes aberrant activation of autophagy promoting viral replication and propagation. It is therefore appealing to study the role of autophagic molecular effectors during viral infection to identify potential targets for anti-ZIKV therapeutic intervention.