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1.
PLoS Negl Trop Dis ; 16(5): e0010426, 2022 May 10.
Article in English | MEDLINE | ID: mdl-35536870

ABSTRACT

During 2015-2016, outbreaks of Zika virus (ZIKV) occurred in Southeast Asia and the Americas. Most ZIKV infections in humans are asymptomatic, while clinical manifestation is usually a self-limiting febrile disease with maculopapular rash. However, ZIKV is capable of inducing a range of severe neurological complications collectively described as congenital Zika syndrome (CZS). Notably, the scale and magnitude of outbreaks in Southeast Asia were significantly smaller compared to those in the Americas. Sequence comparison between epidemic-associated ZIKV strains from Southeast Asia with those from the Americas revealed a methionine to valine substitution at residue position 114 of the NS5 protein (NS5-M114V) in all the American isolates. Using an American isolate of ZIKV (Natal), we investigated the impact of NS5-M114V mutation on virus replication in cells, virulence in interferon (IFN) α/ß receptor knockout (Ifnar-/-) mice, as well as replication and transmission potential in Aedes aegypti mosquitoes. We demonstrated that NS5-M114V mutation had insignificant effect on ZIKV replication efficiency in cells, its ability to degrade STAT2, and virulence in vivo, albeit viremia was slightly prolonged in mice. Furthermore, NS5-M114V mutation decreased mosquito infection and dissemination rates and had no effect on virus secretion into the saliva. Taken together, our findings support the notion that NS5-M114V mutation is unlikely to be a major determinant for virus replication and transmission potential.

3.
Viral Immunol ; 2022 May 03.
Article in English | MEDLINE | ID: mdl-35506896

ABSTRACT

Zika virus (ZIKV) infections have gained notoriety due to congenital abnormalities. Pregnant women have a greater risk of ZIKV infection and consequent transmission to their progeny due to the immunological changes associated with pregnancy. ZIKV has been detected in amniotic fluid, as well as in fetal and neonatal tissues of infected pregnant women. However, the mechanism by which ZIKV reaches the fetus is not well understood. The four dengue virus serotypes have been the most widely used flaviviruses to elucidate the host-cell entry pathways. Nevertheless, it is of increasing interest to understand the specific interaction between ZIKV and the host cell, especially in the gestation period. Herein, the authors describe the mechanisms of prenatal vertical infection of ZIKV based on results from in vitro, in vivo, and ex vivo studies, including murine models and nonhuman primates. It also includes up-to-date knowledge from ex vivo and natural infections in pregnant women explaining the vertical transmission along four tracks: transplacental, paracellular, transcytosis mediated by extracellular vesicles, and paraplacental route and the antibody-dependent enhancement process. A global understanding of the diverse pathways used by ZIKV to cross the placental barrier and access the fetus, along with a better comprehension of the pathogenesis of ZIKV in pregnant females, may constitute a fundamental role in the design of antiviral drugs to reduce congenital disabilities associated with ZIKV.

4.
Cell Rep ; 39(2): 110655, 2022 04 12.
Article in English | MEDLINE | ID: mdl-35417697

ABSTRACT

Zika virus (ZIKV) and dengue virus (DENV) are arthropod-borne pathogenic flaviviruses that co-circulate in many countries. To understand some of the pressures that influence ZIKV evolution, we mimic the natural transmission cycle by repeating serial passaging of ZIKV through cultured mosquito cells and either DENV-naive or DENV-immune mice. Compared with wild-type ZIKV, the strains passaged under both conditions exhibit increased pathogenesis in DENV-immune mice. Application of reverse genetics identifies an isoleucine-to-valine mutation (I39V) in the NS2B proteins of both passaged strains that confers enhanced fitness and escape from pre-existing DENV immunity. Introduction of I39V or I39T, a naturally occurring homologous mutation detected in recent ZIKV isolates, increases the replication of wild-type ZIKV in human neuronal precursor cells and laboratory-raised mosquitoes. Our data indicate that ZIKV strains with enhanced transmissibility and pathogenicity can emerge in DENV-naive or -immune settings, and that NS2B-I39 mutants may represent ZIKV variants of interest.


Subject(s)
Dengue Virus , Dengue , Zika Virus Infection , Zika Virus , Animals , Antibodies, Viral , Cross Reactions , Dengue Virus/genetics , Mice , Mutation/genetics , Zika Virus/genetics
5.
Acta Neuropathol Commun ; 10(1): 46, 2022 04 04.
Article in English | MEDLINE | ID: mdl-35379362

ABSTRACT

The mechanisms by which vertically transmitted Zika virus (ZIKV) causes postnatal brain development abnormalities and congenital disease remain poorly understood. Here, we optimized the established anti-IFNAR1 treated, Rag1-/- (AIR) mouse model of ZIKV infection to examine the consequence of vertical transmission on neonate survival and postnatal brain development. We found that modulating the infectious dose and the frequency of anti-IFNAR1 treatment of pregnant mice (termed AIRlow mice) prolonged neonatal survival allowing for pathogenesis studies of brain tissues at critical postnatal time points. Postnatal AIRlow mice all had chronic ZIKV infection in the brain that was associated with decreased cortical thickness and cerebellar volume, increased gliosis, and higher levels of cell death in many brain areas including cortex, hippocampus and cerebellum when compared to controls. Interestingly, despite active infection and brain abnormalities, the neurodevelopmental program remained active in AIRlow mice as indicated by elevated mRNA expression of critical neurodevelopmental genes in the brain and enlargement of neural-progenitor rich regions of the cerebellum at a developmental time point analogous to birth in humans. Nevertheless, around the developmental time point when the brain is fully populated by neurons, AIRlow mice developed neurologic disease associated with persistent ZIKV infection in the brain, gliosis, and increased cell death. Together, these data show that vertically transmitted ZIKV infection in the brain of postnatal AIRlow mice strongly influences brain development resulting in structural abnormalities and cell death in multiple regions of the brain.


Subject(s)
Brain Diseases , Zika Virus Infection , Zika Virus , Animals , Brain/pathology , Brain Diseases/complications , Female , Homeodomain Proteins , Interferons , Mice , Pregnancy , Receptor, Interferon alpha-beta , Zika Virus/physiology , Zika Virus Infection/complications , Zika Virus Infection/genetics
6.
PLoS Negl Trop Dis ; 16(4): e0010359, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35442976

ABSTRACT

A Zika virus (ZIKV) infection during pregnancy can result in severe birth defects such as microcephaly. To date, it is incompletely understood how ZIKV can cross the human placenta. Furthermore, results from studies in pregnant mice and non-human primates are conflicting regarding the role of cross-reactive dengue virus (DENV) antibodies on transplacental ZIKV transmission. Elucidating how ZIKV can cross the placenta and which risk factors contribute to this is important for risk assessment and for potential intervention strategies for transplacental ZIKV transmission. In this study we use an ex vivo human placental perfusion model to study transplacental ZIKV transmission and the effect that cross-reactive DENV antibodies have on this transmission. By using this model, we demonstrate that DENV antibodies significantly increase ZIKV uptake in perfused human placentas and that this increased uptake is neonatal Fc-receptor-dependent. Furthermore, we show that cross-reactive DENV antibodies enhance ZIKV infection in term human placental explants and in primary fetal macrophages but not in primary trophoblasts. Our data supports the hypothesis that presence of cross-reactive DENV antibodies could be an important risk factor for transplacental ZIKV transmission. Furthermore, we demonstrate that the ex vivo placental perfusion model is a relevant and animal friendly model to study transplacental pathogen transmission.


Subject(s)
Dengue Virus , Dengue , Zika Virus Infection , Zika Virus , Animals , Antibodies, Viral , Cross Reactions , Disease Models, Animal , Female , Humans , Mice , Placenta , Pregnancy
7.
Parasit Vectors ; 15(1): 103, 2022 Mar 24.
Article in English | MEDLINE | ID: mdl-35331315

ABSTRACT

BACKGROUND: Arthropod-borne viruses (arboviruses) impose a major health and economic burden on human populations globally, with mosquitoes serving as important vectors. Measuring the ability of a mosquito population to transmit an arbovirus is important in terms of evaluating its public health risk. In the laboratory, a variety of methods are used to estimate arboviral transmission by mosquitoes, including indirect methods involving viral detection from mosquito saliva collected by forced salivation. The accuracy of indirect methods to estimate arbovirus transmission to live animal hosts has not been fully evaluated. METHODS: We compared three commonly used proxies of arboviral transmission, namely, the presence of virus in mosquito legs, in salivary glands (SG) and in saliva collected in capillary tubes using forced salivation, with direct transmission estimates from mosquitoes to suckling mice. We analyzed five vector-virus combinations, including Aedes aegypti infected with chikungunya virus, West Nile virus and Zika virus; Culex quinquefasciatus infected with West Nile virus; and Aedes triseriatus infected with La Crosse virus. RESULTS: Comparatively, the methods of detecting virus infection in mosquito legs and in SG were equally accurate in predicting transmission. Overall, the presence of virus in mosquito legs was a more accurate predictor of transmission than the commonly implemented viral detection method using forced salivation into a capillary tube, and was subject to less technical variation. CONCLUSIONS: These results suggest that, in general, forced salivation methods tend to underestimate virus transmission, and they provide confidence in the use of mosquito leg screens to evaluate the transmission potential of a mosquito population.


Subject(s)
Aedes , Arboviruses , Zika Virus Infection , Zika Virus , Animals , Mice , Mosquito Vectors , Saliva
8.
Emerg Infect Dis ; 28(4): 701-706, 2022 04.
Article in English | MEDLINE | ID: mdl-35318912

ABSTRACT

Arbovirus epidemiology lacks efficient and timely surveillance systems with accurate outbreak alert signals. We devised a citywide integrated surveillance system combining entomologic, epidemiologic, and entomo-virologic data gathered during 2017-2020 in Foz do Iguaçu, Brazil. We installed 3,476 adult mosquito traps across the city and inspected traps every 2 months. We compared 5 entomologic indices: traditional house and Breteau indices for larval surveys and trap positivity, adult density, and mosquitoes per inhabitant indices for adult trapping. We screened for dengue, Zika, and chikungunya viruses in live adult Aedes aegypti mosquitoes collected from traps. Indices based on adult mosquito sampling had higher outbreak predictive values than larval indices, and we were able to build choropleth maps of infestation levels <36 h after each round of trap inspection. Locating naturally infected vectors provides a timely support tool for local public health managers to prioritize areas for intervention response to prevent virus outbreaks.


Subject(s)
Aedes , Arboviruses , Zika Virus Infection , Zika Virus , Animals , Brazil/epidemiology , Mosquito Vectors , Zika Virus Infection/epidemiology , Zika Virus Infection/prevention & control
9.
Immunol Cell Biol ; 2022 Mar 31.
Article in English | MEDLINE | ID: mdl-35355318

ABSTRACT

Zika virus (ZIKV) has emerged as a significant health threat worldwide. Although typically mosquito-borne, recent evidence suggests that ZIKV is also a sexually transmitted virus. While persistent ZIKV infections in male reproductive tissues have been identified, little is understood regarding the outcomes of primary sexual transmission in females. We investigated how the route of infection affects vaginal ZIKV shedding and dissemination. In two mouse models, vaginal infection resulted in prolonged ZIKV shedding in the vaginal mucosa with delayed systemic infection. Furthermore, heightened vaginal inflammation did not influence ZIKV replication or dissemination, in contrast to previous studies of mosquito-borne infection. Thus, vaginal infection significantly alters ZIKV infection kinetics and must be considered when developing novel treatments.

10.
Front Microbiol ; 13: 813187, 2022.
Article in English | MEDLINE | ID: mdl-35154056

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has caused a pandemic of coronavirus disease 2019 (COVID-19) and is threatening global health. SARS-CoV-2 spreads by air with a transmission rate of up to 15%, but the probability of its maternal-fetal transmission through the placenta is reported to be low at around 3.28%. However, it is still unclear that which tissues and developmental periods hold higher risks and what the underlying molecular mechanisms are. We conducted an integrated analysis of large-scale transcriptome and single-cell sequencing data to investigate the key factors that affect SARS-CoV-2 maternal-fetal transmission as well as the characteristics and effects of them. Our results showed that the abundance of cytomegalovirus (CMV) and Zika virus (ZIKV) infection-associated factors in the placenta were higher than their primarily infected tissues, while the expression levels of SARS-CoV-2 binding receptor angiotensin-converting enzyme II (ACE2) were similar between lung and placenta. By contrast, an important SARS-CoV-2 infection-associated factor, type II transmembrane serine protease (TMPRSS2), was poorly expressed in placenta. Further scRNA-Seq analysis revealed that ACE2 and TMPRSS2 were co-expressed in very few trophoblastic cells. Interestingly, during the embryonic development stages, the abundance of ACE2 and TMPRSS2 was much higher in multiple embryonic tissues than in the placenta. Based on our present analysis, the intestine in 20th week of embryonic development was at a high risk of SARS-CoV-2 infection. Additionally, we found that during the fetal development, ACE2 and TMPRSS2 were enriched in pathogen infection-associated pathways and may involve in the biological processes related to T-cell activation. In conclusion, our present study suggests that though the placenta provides a good physical barrier against SARS-CoV-2 infection for healthy fetal development, multiple embryonic tissues are under risks of the virus infection, which may be adversely affected once infected prenatally. Therefore, it is necessary to enhance maternal care to prevent the potential impact and harm of SARS-CoV-2 maternal-fetal transmission.

11.
Emerg Infect Dis ; 28(2): 453-456, 2022 02.
Article in English | MEDLINE | ID: mdl-35076006

ABSTRACT

Transplacental transmission of Zika virus has been reported during all trimesters of pregnancy and might lead to central nervous system anomalies, including microcephaly. We report 3 cases of perinatal Zika infection identified during the epidemic in Colombia and provide detailed descriptions of clinical features, diagnosis, and neurodevelopmental outcome at 18 months of age (corrected).


Subject(s)
Microcephaly , Pregnancy Complications, Infectious , Zika Virus Infection , Zika Virus , Colombia/epidemiology , Female , Humans , Infant , Infectious Disease Transmission, Vertical , Microcephaly/epidemiology , Microcephaly/etiology , Pregnancy , Zika Virus Infection/diagnosis , Zika Virus Infection/epidemiology
12.
PLoS One ; 17(1): e0261602, 2022.
Article in English | MEDLINE | ID: mdl-35085257

ABSTRACT

BACKGROUND: On 1 February 2016, the World Health Organization declared Zika transmission a public health emergency of international concern. Monitoring and responding to community awareness, concern, and possible knowledge gaps are critical during public health emergencies. Here, we describe the review and analysis of micro-blogs posted on Sina-Weibo, China's largest social media platform, to develop and disseminate a Zika virus education campaign. METHODS: We used CYYUN Voice Express' Weibo Spider tool and the search terms of "Zhaika" OR "Zika" OR "Zikv" to capture microblogs about Zika virus retrospectively from February 1 to December 31, 2016 and prospectively from June 1 to November 15, 2017. We described microblogs meeting our inclusion criteria by month and Zika virus outbreaks in Asia and by source (e.g., government agency, individual, or other). We identified common misleading or inaccurate content authored by individual micro-bloggers (i.e., not supported by available scientific evidence) through a qualitative review. We used this information to develop and disseminate health awareness material about the Zika virus through China CDC's 12320 Health Hotline Weibo account. An online survey was conducted to obtain feedback on the material. RESULTS: We captured 15,888 microblogs meeting our inclusion criteria. Zika-related microblogs peaked in September 2016, corresponding to news reports about the Zika outbreak in Singapore (August to November 2016). Most microblogs (12,994 [82%]) were authored by individual users, followed by media agencies (842 [5%]), businesses (829 [5%]), international organizations (370 [2%]), and Chinese government agencies (235 [1%]). Relevant microblogs primarily focused on clinical symptoms and health risks, modes of transmission, and actions taken by individuals to prevent infection and seek health care. Incorrect and/or mis-leading information from individual users concentrated on modes of transmission and possible treatments. The microblog "#Zika is that far and this close" health campaign was posted on Sina-Weibo and Baidu (Internet search engine in China) on September 18, 2016. Younger respondents (p-value = 0.01), and those with at least a college education (p-value = 0.03), were more likely than other respondents to consider the online campaign reliable and trustworthy. CONCLUSION: Routine review of Sina-Weibo and other social media platforms could enhance the ability of public health staff to effectively respond to community concerns and awareness during public health emergencies. Advancements of social media monitoring tools and staff training could help to promote health awareness during emergencies by directly addressing public perceptions and concerns. Various approaches may be needed to reach different at-risk populations, particularly older and less educated populations who may prefer more traditional modes of communication.


Subject(s)
Health Promotion/methods , Zika Virus Infection/epidemiology , Zika Virus Infection/transmission , Blogging , China/epidemiology , Health Knowledge, Attitudes, Practice , Humans , Pilot Projects , Public Health , Qualitative Research , Retrospective Studies , Social Media
13.
J Med Entomol ; 59(2): 659-666, 2022 03 16.
Article in English | MEDLINE | ID: mdl-35064663

ABSTRACT

Aedes albopictus (Skuse) and Aedes aegypti (Linnaeus) (Diptera: Culicidae) mosquitoes transmit pathogenic arthropod-borne viruses, including dengue, chikungunya, and Zika viruses, with significant global health consequences. Both Ae. albopictus and Ae. aegypti also are susceptible to Aedes flavivirus (AEFV), an insect-specific flavivirus (ISF) first isolated in Japan from Ae. albopictus and Ae. flavopictus. ISFs infect only insect hosts and evidence suggests that they are maintained by vertical transmission. In some cases, ISFs interfere with pathogenic flavivirus infection, and may have potential use in disease control. We explored the host range of AEFV in 4 genera of mosquitoes after intrathoracic injection and observed greater than 95% prevalence in the species of Aedes and Toxorhynchites tested. Anopheles and Culex species were less permissive to infection. Vertical transmission studies revealed 100% transovarial transmission and a filial infection rate of 100% for AEFV in a persistently-infected colony of Ae. albopictus. Horizontal transmission potential was assessed for adult and larval mosquitoes following per os exposures and in venereal transmission experiments. No mosquitoes tested positive for AEFV infection after blood feeding, and infection with AEFV after sucrose feeding was rare. Similarly, 2% of adult mosquitoes tested positive for AEFV after feeding on infected cells in culture as larvae. Venereal transmission of AEFV was most frequently observed from infected males to uninfected females as compared with transmission from infected females to uninfected males. These results reveal new information on the infection potential of AEFV in mosquitoes and expand our understanding of both vertical and horizontal transmission of ISFs.


Subject(s)
Aedes , Flavivirus , Zika Virus Infection , Zika Virus , Animals , Biology , Female , Insecta , Larva , Male , Mosquito Vectors
14.
EBioMedicine ; 77: 103930, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35290828

ABSTRACT

BACKGROUND: Congenital disorders associated with prenatal vertical transmission of Zika virus (ZIKV) is well established since the 2016 outbreak in the Americas. However, despite clinical reports of similar mode of transmission for other flaviviruses such as dengue virus (DENV), the phenomenon has not been experimentally explored. METHODS: Pregnant AG129 mice were infected with DENV1 in the presence or absence of enhancing antibodies at different gestational time points. ZIKV was used for comparison. We quantified viral load in fetus and placentas and performed comprehensive gene expression profiling in the maternal (decidua) and fetal portion of placenta separately. FINDINGS: We demonstrate in a laboratory experimental setting that DENV can be transmitted vertically in a gestation stage-dependent manner similar to ZIKV, and this incidence drastically increases in the presence of enhancing antibodies. Interestingly, a high rate of DENV fetal infection occurs even though the placental viral load is significantly lower than that found in ZIKV-infected dams. Comprehensive gene expression profiling revealed DENV infection modulates a variety of inflammation-associated genes comparable to ZIKV in decidua and fetal placenta in early pregnancy. INTERPRETATION: Our findings suggest that the virus-induced modulation of host gene expression may facilitate DENV to cross the placental barrier in spite of lower viral burden compared to ZIKV. This mouse model may serve to identify the host determinants required for the vertical transmission of flaviviruses and develop appropriate countermeasures. FUNDING: National Medical Research Council/Open Fund Individual Research Grant MOH-000524 (SW), MOH-000086 and OFIRG20nov-0017 (SGV).


Subject(s)
Dengue Virus , Zika Virus Infection , Zika Virus , Animals , Antibodies, Viral , Female , Humans , Mice , Placenta , Pregnancy , Zika Virus/genetics
15.
Am J Trop Med Hyg ; 106(2): 585-592, 2021 12 20.
Article in English | MEDLINE | ID: mdl-34929668

ABSTRACT

Serological cross-reactivity has proved to be a challenge to diagnose Zika virus (ZIKV) infections in dengue virus (DENV) endemic countries. Confirmatory testing of ZIKV IgM positive results by plaque reduction neutralization tests (PRNTs) provides clarification in only a minority of cases because most individuals infected with ZIKV were previously exposed to DENV. The goal of this study was to evaluate the performance of a ZIKV/DENV DUO IgM antibody capture ELISA (MAC-ELISA) for discriminating between DENV and ZIKV infections in endemic regions. Our performance evaluation included acute and convalescent specimens from patients with real-time reverse transcription polymerase chain reaction (RT-PCR)-confirmed DENV or ZIKV from the Sentinel Enhanced Dengue Surveillance System in Ponce, Puerto Rico. The ZIKV/DENV DUO MAC-ELISA specificity was 100% for DENV (N = 127) and 98.4% for ZIKV (N = 275) when specimens were tested during the optimal testing window (days post-onset of illness [DPO] 6-120). The ZIKV/DENV DUO MAC-ELISA sensitivity of RT-PCR confirmed specimens reached 100% for DENV by DPO 6 and for ZIKV by DPO 9. Our new ZIKV/DENV DUO MAC-ELISA was also able to distinguish ZIKV and DENV regardless of previous DENV exposure. We conclude this novel serologic diagnostic assay can accurately discriminate ZIKV and DENV infections. This can potentially be useful considering that the more labor-intensive and expensive PRNT assay may not be an option for confirmatory diagnosis in areas that lack PRNT capacity, but experience circulation of both DENV and ZIKV.


Subject(s)
Antibodies, Viral/immunology , Dengue/diagnosis , Enzyme-Linked Immunosorbent Assay/methods , Immunoglobulin M/immunology , Zika Virus Infection/diagnosis , Cross Reactions , Dengue/immunology , Dengue/transmission , Dengue Virus/immunology , Endemic Diseases , Female , Humans , Male , Serologic Tests/methods , Viral Nonstructural Proteins , Zika Virus/immunology , Zika Virus Infection/immunology , Zika Virus Infection/transmission
16.
Article in English | MEDLINE | ID: mdl-34957474

ABSTRACT

Zika virus (ZIKV) was first discovered in 1947 in Uganda. ZIKV did not entice much attention until Brazil hosted the 2016 Summer Olympics Game, where ZIKV attracted a global audience. ZIKV is a flavivirus that can be transmitted chiefly through the biting of the mosquito or sexually or by breastfeeding at a lower scale. As time passed, the recent discovery of how the ZIKV causes congenital neurodevelopmental defects, including microcephaly, makes us reevaluate the importance of ZIKV interaction with centrosome organization because centrosome plays an important role in cell division. When the ZIKV disrupts centrosome organization and mitotic abnormalities, this will alter neural progenitor differentiation. Altering the neural progenitor differentiation will lead to cell cycle arrest, increase apoptosis, and inhibit the neural progenitor cell differentiation, as this can lead to abnormalities in neural cell development resulting in microcephaly. Understanding the importance of ZIKV infection throughout the years, this review article gives an overview of the history, transmission routes, pathogenesis, animal models, and diagnosis.

17.
Parasit Vectors ; 14(1): 610, 2021 Dec 19.
Article in English | MEDLINE | ID: mdl-34924014

ABSTRACT

BACKGROUND: Vector-borne diseases, especially arboviruses transmitted by Aedes sp. mosquitos, should be a health policy priority in Brazil. Despite this urgency, there are significant limitations in the traditional surveillance system, mainly in vulnerable areas. This study aimed to investigate the circulation of dengue (DENV), Zika (ZIKV), and chikungunya viruses (CHIKV) by laboratory syndromic surveillance (LSS) in a slum area of the Federal District of Brazil, comparing the results with traditional surveillance data. METHODS: LSS for acute febrile and/or exanthematous symptoms was developed at a health unit of Cidade Estrutural, in order to identify the circulation of arboviruses transmitted by Aedes sp. mosquitos. Between June 2019 and March 2020, 131 valid participants were identified and sera tested by reverse transcription polymerase chain reaction (RT-PCR) for DENV (by serotype), ZIKV, and CHIKV acute infection and by immunoglobulin M enzyme-inked immunosorbent assay (ELISA-IgM) for DENV and CHIKV 15-21 days after symptom onset, when the participant reported no respiratory signs (cough and/or coryza). The results obtained were compared with traditional surveillance data for the study area and period. RESULTS: At least three DENV-1 (2.3%), four DENV-2 (3%), and one CHIKV (0.7%) cases were confirmed in the laboratory, showing evidence of hyperendemicity even though LSS had not reached the historic peak dengue fever months in the Federal District (April-May). When the results obtained here were compared with traditional surveillance, a significant discrepancy was observed, including underreporting of CHIKV infection. CONCLUSIONS: In addition to the risks posed to the study population, the area investigated with its respective socio-environmental profile may be a potential site for spread of the virus, given the cosmopolitan presence of Aedes sp. and human mobility in the Federal District. It is also suggested that traditional epidemiological surveillance may be reporting acute viral infections other than DENV as dengue fever, while underreporting other arboviruses transmitted by Aedes sp. mosquitos in the Federal District.


Subject(s)
Aedes/virology , Arbovirus Infections/epidemiology , Arbovirus Infections/virology , Arboviruses/isolation & purification , Poverty Areas , RNA, Viral/isolation & purification , Animals , Brazil/epidemiology , Humans , Population Surveillance , Reverse Transcriptase Polymerase Chain Reaction , Risk Factors
18.
Viruses ; 13(11)2021 11 08.
Article in English | MEDLINE | ID: mdl-34835050

ABSTRACT

Following the recent outbreak of Zika virus (ZIKV) infections in Latin America, ZIKV has emerged as a global health threat due to its ability to induce neurological disease in both adults and the developing fetus. ZIKV is largely mosquito-borne and is now endemic in many parts of Africa, Asia, and South America. However, several reports have demonstrated persistent ZIKV infection of the male reproductive tract and evidence of male-to-female sexual transmission of ZIKV. Sexual transmission may broaden the reach of ZIKV infections beyond its current geographical limits, presenting a significant threat worldwide. Several mouse models of ZIKV infection have been developed to investigate ZIKV pathogenesis and develop effective vaccines and therapeutics. However, the majority of these models focus on mosquito-borne infection, while few have considered the impact of sexual transmission on immunity and pathogenesis. This review will examine the advantages and disadvantages of current models of mosquito-borne and sexually transmitted ZIKV and provide recommendations for the effective use of ZIKV mouse models.


Subject(s)
Disease Models, Animal , Sexually Transmitted Diseases, Viral/transmission , Zika Virus Infection/transmission , Animals , Female , Mice , Pregnancy , Pregnancy Complications, Infectious/prevention & control , Pregnancy Complications, Infectious/virology , Sexually Transmitted Diseases, Viral/prevention & control , Vector Borne Diseases/prevention & control , Vector Borne Diseases/transmission , Vector Borne Diseases/virology , Zika Virus/physiology , Zika Virus Infection/prevention & control , Zika Virus Infection/virology
19.
BMC Microbiol ; 21(1): 300, 2021 10 30.
Article in English | MEDLINE | ID: mdl-34717555

ABSTRACT

BACKGROUND: Zika fever has been a global health security threat, especially in the tropical and subtropical regions where most of the cases occur. The disease is caused by Zika virus (ZIKV), which belongs to the family Flaviviridae, genus Flavivirus. The virus is transmitted by Aedes mosquitoes, mostly by Aedes aegypti, during its blood meal. In this study we present a descriptive analysis, by transmission electron microscopy (TEM), of ZIKV infection in A. aegypti elected tissues at the 3rd day of infection. ZIKV vertical transmission experiments by oral infection were conducted to explore an offspring of natural infection. RESULTS: Gut and ovary tissues harbored a higher number of viral particles. The ZIKV genome was also detected, by RT-qPCR technique, in the organism of orally infected female mosquitoes and in their eggs laid. CONCLUSIONS: The data obtained suggest that the ovary is an organ susceptible to be infected with ZIKV and that virus can be transmitted from mother to a fraction of the progeny.


Subject(s)
Aedes/virology , Mosquito Vectors/virology , Zika Virus/physiology , Animals , Female , Intestines/virology , Microscopy, Electron, Transmission , Ovary/virology , Ovum/virology , RNA, Viral/genetics , Virion/ultrastructure , Zika Virus/ultrastructure , Zika Virus Infection/transmission , Zika Virus Infection/virology
20.
Nat Commun ; 12(1): 6018, 2021 10 14.
Article in English | MEDLINE | ID: mdl-34650045

ABSTRACT

Mosquito bites transmit a number of pathogens via salivary droplets deposited during blood-feeding, resulting in potentially fatal diseases. Little is known about the genomic content of these nanodroplets, including the transmission dynamics of live pathogens. Here we introduce Vectorchip, a low-cost, scalable microfluidic platform enabling high-throughput molecular interrogation of individual mosquito bites. We introduce an ultra-thin PDMS membrane which acts as a biting interface to arrays of micro-wells. Freely-behaving mosquitoes deposit saliva droplets by biting into these micro-wells. By modulating membrane thickness, we observe species-dependent differences in mosquito biting capacity, utilizable for selective sample collection. We demonstrate RT-PCR and focus-forming assays on-chip to detect mosquito DNA, Zika virus RNA, as well as quantify infectious Mayaro virus particles transmitted from single mosquito bites. The Vectorchip presents a promising approach for single-bite-resolution laboratory and field characterization of vector-pathogen communities, and could serve as a powerful early warning sentinel for mosquito-borne diseases.


Subject(s)
Culicidae/physiology , Insect Bites and Stings , Microfluidics/methods , Mosquito Vectors/physiology , Aedes/physiology , Animals , Female , High-Throughput Screening Assays , Mosquito Vectors/virology , Saliva/virology , Zika Virus , Zika Virus Infection/epidemiology , Zika Virus Infection/transmission
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