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1.
Proc Natl Acad Sci U S A ; 121(21): e2312755121, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38743628

RESUMEN

Antigenic similarities between Zika virus (ZIKV) and other flaviviruses pose challenges to the development of virus-specific diagnostic tools and effective vaccines. Starting with a DNA-encoded one-bead-one-compound combinatorial library of 508,032 synthetic, non-natural oligomers, we selected and characterized small molecules that mimic ZIKV epitopes. High-throughput fluorescence-activated cell sorter-based bead screening was used to select molecules that bound IgG from ZIKV-immune but not from dengue-immune sera. Deep sequencing of the DNA from the "Zika-only" beads identified 40 candidate molecular structures. A lead candidate small molecule "CZV1-1" was selected that correctly identifies serum specimens from Zika-experienced patients with good sensitivity and specificity (85.3% and 98.4%, respectively). Binding competition studies of purified anti-CZV1-1 IgG against known ZIKV-specific monoclonal antibodies (mAbs) showed that CZV1-1 mimics a nonlinear, neutralizing conformational epitope in the domain III of the ZIKV envelope. Purified anti-CZV1-1 IgG neutralized infection of ZIKV in cell cultures with potencies comparable to highly specific ZIKV-neutralizing mAbs. This study demonstrates an innovative approach for identification of synthetic non-natural molecular mimics of conformational virus epitopes. Such molecular mimics may have value in the development of accurate diagnostic assays for Zika, as well as for other viruses.


Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , Epítopos , Infección por el Virus Zika , Virus Zika , Virus Zika/inmunología , Epítopos/inmunología , Humanos , Infección por el Virus Zika/inmunología , Infección por el Virus Zika/virología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Inmunoglobulina G/inmunología , Anticuerpos Monoclonales/inmunología , Imitación Molecular/inmunología
2.
Viruses ; 16(5)2024 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-38793609

RESUMEN

Dengue virus (DENV) is a continuing global threat that puts half of the world's population at risk for infection. This mosquito-transmitted virus is endemic in over 100 countries. When a mosquito takes a bloodmeal, virus is deposited into the epidermal and dermal layers of human skin, infecting a variety of permissive cells, including keratinocytes, Langerhans cells, macrophages, dermal dendritic cells, fibroblasts, and mast cells. In response to infection, the skin deploys an array of defense mechanisms to inhibit viral replication and prevent dissemination. Antimicrobial peptides, pattern recognition receptors, and cytokines induce a signaling cascade to increase transcription and translation of pro-inflammatory and antiviral genes. Paradoxically, this inflammatory environment recruits skin-resident mononuclear cells that become infected and migrate out of the skin, spreading virus throughout the host. The details of the viral-host interactions in the cutaneous microenvironment remain unclear, partly due to the limited body of research focusing on DENV in human skin. This review will summarize the functional role of human skin, the cutaneous innate immune response to DENV, the contribution of the arthropod vector, and the models used to study DENV interactions in the cutaneous environment.


Asunto(s)
Virus del Dengue , Dengue , Inmunidad Innata , Piel , Animales , Humanos , Citocinas/inmunología , Citocinas/metabolismo , Dengue/inmunología , Dengue/virología , Virus del Dengue/inmunología , Virus del Dengue/fisiología , Interacciones Huésped-Patógeno/inmunología , Piel/virología , Piel/inmunología , Replicación Viral , Artrópodos/virología
3.
Am J Trop Med Hyg ; 110(3): 470-482, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38350158

RESUMEN

Lymphatic filariasis (LF) is a leading cause of disability due to infectious disease worldwide. The Recife Metropolitan Region (RMR) is the only remaining focus of LF in Brazil, where the parasite Wuchereria bancrofti is transmitted solely by the mosquito Culex quinquefasciatus. This study reports the results of transmission assessment surveys and molecular xenomonitoring in the city of Olinda, RMR, after nearly 15 years (2015-2016) of interventions for LF elimination. Participants were screened for W. bancrofti antigen via immunochromatographic card tests (ICT) in: 1) door-to-door surveys conducted for all children aged 5-7 years from 4 out of 17 intervention areas treated with at least five annual doses of mass drug administration (MDA), and 2) a two-stage cluster sampling survey of residents aged 5 years and older in non-MDA areas. Mosquitoes were collected via handheld aspirators in four MDA areas, differentiated by species, sex, and physiological status, pooled into groups of up to 10 blood-fed, semigravid, and gravid mosquitoes, and screened for W. bancrofti infection by real-time quantitative polymerase chain reaction (RT-qPCR). All 1,170 children from MDA areas and the entire population sample of 990 residents in non-MDA areas were ICT negative. In MDA areas, a total of 3,152 female Cx. quinquefasciatus mosquitoes in 277 households (range, 0-296 mosquitoes per house) were collected via aspiration. RT-qPCR of 233 pools of mosquitos were negative for W. bancrofti RNA; an independent reference laboratory confirmed these results. These results provide evidence that LF transmission has been halted in this setting.


Asunto(s)
Culex , Culicidae , Filariasis Linfática , Niño , Animales , Humanos , Femenino , Filariasis Linfática/epidemiología , Filariasis Linfática/prevención & control , Filariasis Linfática/tratamiento farmacológico , Brasil/epidemiología , Culex/genética , Wuchereria bancrofti
4.
J Infect Dis ; 229(4): 1147-1157, 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38035792

RESUMEN

BACKGROUND: Immune dysregulation in people with human immunodeficiency virus-1 (PWH) persists despite potent antiretroviral therapy and, consequently, PWH tend to have lower immune responses to licensed vaccines. However, limited information is available about the impact of mRNA vaccines in PWH. This study details the immunologic responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccines in PWH and their impact on HIV-1. METHODS: We quantified anti-S immunoglobulin G (IgG) binding and neutralization of 3 SARS-CoV-2 variants of concern and complement activation in blood from virally suppressed men with HIV-1 (MWH) and men without HIV-1 (MWOH), and the characteristics that may impact the vaccine immune responses. We also studied antibody levels against HIV-1 proteins and HIV-1 plasma RNA. RESULTS: MWH had lower anti-S IgG binding and neutralizing antibodies against the 3 variants compared to MWOH. MWH also produced anti-S1 antibodies with a 10-fold greater ability to activate complement and exhibited higher C3a blood levels than MWOH. MWH had decreased residual HIV-1 plasma viremia and anti-Nef IgG approximately 100 days after immunization. CONCLUSIONS: MWH respond to SARS-CoV-2 mRNA vaccines with lower antibody titers and with greater activation of complement, while exhibiting a decrease in HIV-1 viremia and anti-Nef antibodies. These results suggest an important role of complement activation mediating protection in MWH.


Asunto(s)
COVID-19 , Seropositividad para VIH , VIH-1 , Masculino , Humanos , Vacunas contra la COVID-19 , Viremia , SARS-CoV-2 , Vacunas de ARNm , COVID-19/prevención & control , Activación de Complemento , Anticuerpos Neutralizantes , Inmunoglobulina G , Anticuerpos Antivirales
5.
Curr Top Behav Neurosci ; 61: 243-264, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36059003

RESUMEN

BACKGROUND: Herpesviruses alter cognitive functions in humans following acute infections; progressive cognitive decline and dementia have also been suggested. It is important to understand the pathogenic mechanisms of such infections. The complement system - comprising functionally related proteins integral for systemic innate and adaptive immunity - is an important component of host responses. The complement system has specialized functions in the brain. Still, the dynamics of the brain complement system are still poorly understood. Many complement proteins have limited access to the brain from plasma, necessitating synthesis and specific regulation of expression in the brain; thus, complement protein synthesis, activation, regulation, and signaling should be investigated in human brain-relevant cellular models. Cells derived from human-induced pluripotent stem cells (hiPSCs) could enable tractable models. METHODS: Human-induced pluripotent stem cells were differentiated into neuronal (hi-N) and microglial (hi-M) cells that were cultured with primary culture human astrocyte-like cells (ha-D). Gene expression analyses and complement protein levels were analyzed in mono- and co-cultures. RESULTS: Transcript levels of complement proteins differ by cell type and co-culture conditions, with evidence for cellular crosstalk in co-cultures. Hi-N and hi-M cells have distinct patterns of expression of complement receptors, soluble factors, and regulatory proteins. hi-N cells produce complement factor 4 (C4) and factor B (FB), whereas hi-M cells produce complement factor 2 (C2) and complement factor 3 (C3). Thus, neither hi-N nor hi-M cells can form either of the C3-convertases - C4bC2a and C3bBb. However, when hi-N and hi-M cells are combined in co-cultures, both types of functional C3 convertase are produced, indicated by elevated levels of the cleaved C3 protein, C3a. CONCLUSIONS: hiPSC-derived co-culture models can be used to study viral infection in the brain, particularly complement receptor and function in relation to cellular "crosstalk." The models could be refined to further investigate pathogenic mechanisms.


Asunto(s)
Infecciones por Herpesviridae , Células Madre Pluripotentes Inducidas , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Complemento C3/metabolismo , Neuronas/metabolismo , Convertasas de Complemento C3-C5/metabolismo , Encéfalo/metabolismo , Infecciones por Herpesviridae/metabolismo
6.
Am J Trop Med Hyg ; 107(1): 186-189, 2022 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-35895363

RESUMEN

It is currently not clear whether humoral immunity to Zika virus (ZIKV) elicited upon natural ZIKV infection is long-lasting. In addition, cross-reactivity of anti-ZIKV antibodies with antigenically related dengue viruses (DENV) may have biological implications in nonnaive individuals who subsequently acquire a heterotypic infection. Cross-reactive humoral immunity between ZIKV and DENV also complicates the interpretation of serological tests to evaluate previous exposure to either virus. Here, we have measured the 2-year decay of ZIKV neutralizing antibodies in people living in a ZIKV/DENV endemic area in Brazil who were identified as having an acute infection (group 1) or past (but recent) infection (group 2) with ZIKV in 2015-16. The titers of neutralizing antibodies to ZIKV decreased 9.1 and 2.3 times in groups 1 and 2, respectively. We also show that the plaque reduction neutralization assay (PRNT) is a reliable method to measure past exposure to ZIKV in coendemic areas.


Asunto(s)
Virus del Dengue , Dengue , Infección por el Virus Zika , Virus Zika , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Brasil/epidemiología , Reacciones Cruzadas , Humanos
7.
J Infect Dis ; 226(5): 766-777, 2022 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-35267024

RESUMEN

BACKGROUND: Excessive complement activation has been implicated in the pathogenesis of coronavirus disease 2019 (COVID-19), but the mechanisms leading to this response remain unclear. METHODS: We measured plasma levels of key complement markers, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA and antibodies against SARS-CoV-2 and seasonal human common cold coronaviruses (CCCs) in hospitalized patients with COVID-19 of moderate (n = 18) and critical severity (n = 37) and in healthy controls (n = 10). RESULTS: We confirmed that complement activation is systemically increased in patients with COVID-19 and is associated with a worse disease outcome. We showed that plasma levels of C1q and circulating immune complexes were markedly increased in patients with severe COVID-19 and correlated with higher immunoglobulin (Ig) G titers, greater complement activation, and higher disease severity score. Additional analyses showed that the classical pathway was the main arm responsible for augmented complement activation in severe patients. In addition, we demonstrated that a rapid IgG response to SARS-CoV-2 and an anamnestic IgG response to the nucleoprotein of the CCCs were strongly correlated with circulating immune complex levels, complement activation, and disease severity. CONCLUSIONS: These findings indicate that early, nonneutralizing IgG responses may play a key role in complement overactivation in severe COVID-19. Our work underscores the urgent need to develop therapeutic strategies to modify complement overactivation in patients with COVID-19.


Asunto(s)
COVID-19 , Anticuerpos Antivirales , Proteínas de la Nucleocápside de Coronavirus , Humanos , Inmunoglobulina G , SARS-CoV-2
8.
Clin Infect Dis ; 74(9): 1525-1533, 2022 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-34374761

RESUMEN

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral RNA (vRNA) is detected in the bloodstream of some patients with coronavirus disease 2019 (COVID-19), but it is not clear whether this RNAemia reflects viremia (ie, virus particles) and how it relates to host immune responses and outcomes. METHODS: SARS-CoV-2 vRNA was quantified in plasma samples from observational cohorts of 51 COVID-19 patients including 9 outpatients, 19 hospitalized (non-intensive care unit [ICU]), and 23 ICU patients. vRNA levels were compared with cross-sectional indices of COVID-19 severity and prospective clinical outcomes. We used multiple imaging methods to visualize virions in plasma. RESULTS: SARS-CoV-2 vRNA was detected in plasma of 100%, 52.6%, and 11.1% of ICU, non-ICU, and outpatients, respectively. Virions were detected in plasma pellets using electron tomography and immunostaining. Plasma vRNA levels were significantly higher in ICU > non-ICU > outpatients (P < .0001); for inpatients, plasma vRNA levels were strongly associated with higher World Health Organization (WHO) score at admission (P = .01), maximum WHO score (P = .002), and discharge disposition (P = .004). A plasma vRNA level >6000 copies/mL was strongly associated with mortality (hazard ratio, 10.7). Levels of vRNA were significantly associated with several inflammatory biomarkers (P < .01) but not with plasma neutralizing antibody titers (P = .8). CONCLUSIONS: Visualization of virus particles in plasma indicates that SARS-CoV-2 RNAemia is due, at least in part, to viremia. The levels of SARS-CoV-2 RNAemia correlate strongly with disease severity, patient outcome, and specific inflammatory biomarkers but not with neutralizing antibody titers.


Asunto(s)
COVID-19 , Anticuerpos Neutralizantes , Biomarcadores , COVID-19/diagnóstico , Estudios Transversales , Humanos , Estudios Prospectivos , ARN Viral , SARS-CoV-2 , Viremia
10.
Viruses ; 13(5)2021 04 23.
Artículo en Inglés | MEDLINE | ID: mdl-33922819

RESUMEN

The diagnostic of arbovirus-related obstetric complications in high-risk pregnancy and childbirth care is challenging, especially in endemic areas. We conducted a prospective study to track active or recent Zika (ZIKV), dengue (DENV), or chikungunya (CHIKV) virus infection among hospitalized pregnant women (PW) with obstetric complications in a hospital at the epicenter of Zika outbreak and ZIKV-related microcephaly in Brazil. Clinical data and blood samples were collected at enrollment and 10 days after the admission of study participants, between October 2018 and May 2019. Further clinical data were extracted from medical records. Samples were screened by molecular and serological tests. Out of 780 participants, 93.1% (95% CI: 91.1-94.7%) presented previous DENV exposure (IgG). ZIKV, CHIKV, and/or DENV laboratory markers of recent or active infection were detected in 130 PW, yielding a prevalence of 16.6% (95% CI: 14.2-19.5%); 9.4% (95% CI: 7.4-11.7%), 7.4% (95% CI: 5.7-9.7%), and 0.38% (95% CI: 0.1-1.2%) of CHIKV, ZIKV, and DENV infections, respectively. Most ZIKV infections were detected by molecular assays (89.6%), while CHIKV infections were detected by serology (95.9%). Our findings highlight the need for arbovirus infections screening in PW with obstetrical complications, potentially associated to these infections in endemic areas regardless of the signs or symptoms suggestive of arboviral disease.


Asunto(s)
Fiebre Chikungunya/epidemiología , Virus Chikungunya , Infección Hospitalaria/epidemiología , Complicaciones Infecciosas del Embarazo/epidemiología , Infección por el Virus Zika/epidemiología , Virus Zika , Adolescente , Adulto , Brasil/epidemiología , Infección Hospitalaria/virología , Susceptibilidad a Enfermedades , Femenino , Humanos , Incidencia , Persona de Mediana Edad , Embarazo , Complicaciones Infecciosas del Embarazo/virología , Estudios Prospectivos , Vigilancia en Salud Pública , Factores de Riesgo , Adulto Joven
12.
J Infect Dis ; 223(4): 673-685, 2021 02 24.
Artículo en Inglés | MEDLINE | ID: mdl-32888023

RESUMEN

BACKGROUND: Zika virus (ZIKV) is a mosquito-borne virus that is also transmitted sexually; however, the epidemiological relevance of ZIKV sexual transmission in endemic regions is unclear. METHODS: We performed a household-based serosurvey in Northeast Brazil to evaluate the differential exposure to ZIKV and chikungunya virus (CHIKV) among households. Individuals who participated in our previous arboviral disease cohort (indexes) were recontacted and enrolled, and their household members were newly enrolled. RESULTS: The relative risk of sexual partners being ZIKV-seropositive when living with a ZIKV-seropositive index participant was significantly higher, whereas this was not observed among nonsexual partners of the index. For CHIKV, both sexual and nonsexual partner household members living with a CHIKV-seropositive index had a significantly higher risk of being seropositive. In the nonindex-based dyadic and generalized linear mixed model analyses, the odds of sexual dyads having a concordant ZIKV plaque reduction neutralization test result was significantly higher. We have also analyzed retrospective clinical data according to the participants' exposure to ZIKV and CHIKV. CONCLUSIONS: Our data suggest that ZIKV sexual transmission may be a key factor for the high ZIKV seroprevalence among households in endemic areas and raises important questions about differential disease from the 2 modes of transmission.


Asunto(s)
Parejas Sexuales , Enfermedades Virales de Transmisión Sexual/epidemiología , Infección por el Virus Zika/epidemiología , Infección por el Virus Zika/transmisión , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antivirales/sangre , Brasil/epidemiología , Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/transmisión , Virus Chikungunya/inmunología , Niño , Preescolar , Composición Familiar , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Riesgo , Estudios Seroepidemiológicos , Conducta Sexual , Enfermedades Virales de Transmisión Sexual/transmisión , Adulto Joven , Virus Zika/inmunología
13.
Viruses ; 12(12)2020 11 30.
Artículo en Inglés | MEDLINE | ID: mdl-33266129

RESUMEN

The emergence and rapid spread of Zika virus (ZIKV) on a global scale as well as the establishment of a causal link between Zika infection and congenital syndrome and neurological disorders triggered unprecedented efforts towards the development of a safe and effective Zika vaccine. Multiple vaccine platforms, including purified inactivated virus, nucleic acid vaccines, live-attenuated vaccines, and viral-vectored vaccines, have advanced to human clinical trials. In this review, we discuss the recent advances in the field of Zika vaccine development and the challenges for future clinical efficacy trials. We provide a brief overview on Zika vaccine platforms in the pipeline before summarizing the vaccine candidates in clinical trials, with a focus on recent, promising results from vaccine candidates that completed phase I trials. Despite low levels of transmission during recent years, ZIKV has become endemic in the Americas and the potential of large Zika outbreaks remains real. It is important for vaccine developers to continue developing their Zika vaccines, so that a potential vaccine is ready for deployment and clinical efficacy trials when the next ZIKV outbreak occurs.


Asunto(s)
Vacunas Virales/inmunología , Infección por el Virus Zika/inmunología , Infección por el Virus Zika/virología , Virus Zika/inmunología , Ensayos Clínicos como Asunto , Brotes de Enfermedades , Evaluación Preclínica de Medicamentos , Salud Global , Humanos , Evaluación de Resultado en la Atención de Salud , Vigilancia en Salud Pública , Vacunas Atenuadas/inmunología , Vacunas Sintéticas/inmunología , Vacunología/métodos , Infección por el Virus Zika/epidemiología , Infección por el Virus Zika/prevención & control
15.
JCI Insight ; 5(3)2020 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-31910161

RESUMEN

Dengue virus (DENV) and Zika virus (ZIKV) are closely related mosquito-borne flaviviruses that co-circulate in tropical regions and constitute major threats to global human health. Whether preexisting immunity to one virus affects disease caused by the other during primary or secondary infections is unknown but is critical in preparing for future outbreaks and predicting vaccine safety. Using a human skin explant model, we show that DENV-3 immune sera increased recruitment and infection of Langerhans cells, macrophages, and dermal dendritic cells following inoculation with DENV-2 or ZIKV. Similarly, ZIKV immune sera enhanced infection with DENV-2. Immune sera increased migration of infected Langerhans cells to the dermis and emigration of infected cells out of skin. Heterotypic immune sera increased viral RNA in the dermis almost 10-fold and reduced the amount of virus required to infect a majority of myeloid cells by 100- to 1000-fold. Enhancement was associated with cross-reactive IgG and induction of IL-10 expression and was mediated by both CD32 and CD64 Fcγ receptors. These findings reveal that preexisting heterotypic immunity greatly enhances DENV and ZIKV infection, replication, and spread in human skin. This relevant tissue model will be valuable in assessing the efficacy and risk of dengue and Zika vaccines in humans.


Asunto(s)
Virus del Dengue/inmunología , Dengue/inmunología , Piel/virología , Infección por el Virus Zika/inmunología , Virus Zika/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/sangre , Reacciones Cruzadas/inmunología , Humanos , Sueros Inmunes
16.
Front Immunol ; 10: 1928, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31474994

RESUMEN

Zika virus (ZIKV) infection during pregnancy is associated with microcephaly, a congenital malformation resulting from neuroinflammation and direct effects of virus replication on the developing central nervous system (CNS). However, the exact changes in the affected CNS remain unknown. Here, we show by transcriptome analysis (at 48 h post-infection) and multiplex immune profiling that human induced-neuroprogenitor stem cells (hiNPCs) respond to ZIKV infection with a strong induction of type-I interferons (IFNs) and several type-I IFNs stimulated genes (ISGs), notably cytokines and the pro-apoptotic chemokines CXCL9 and CXCL10. By comparing the inflammatory profile induced by a ZIKV Brazilian strain with an ancestral strain isolated from Cambodia in 2010, we observed that the response magnitude differs among them. Compared to ZIKV/Cambodia, the experimental infection of hiNPCs with ZIKV/Brazil resulted in a diminished induction of ISGs and lower induction of several cytokines (IFN-α, IL-1α/ß, IL-6, IL-8, and IL-15), consequently favoring virus replication. From ZIKV-confirmed infant microcephaly cases, we detected a similar profile characterized by the presence of IFN-α, CXCL10, and CXCL9 in cerebrospinal fluid (CSF) samples collected after birth, evidencing a sustained CNS inflammation. Altogether, our data suggest that the CNS may be directly affected due to an unbalanced and chronic local inflammatory response, elicited by ZIKV infection, which contributes to damage to the fetal brain.


Asunto(s)
Sistema Nervioso Central/inmunología , Células Madre Pluripotentes Inducidas/citología , Microcefalia/inmunología , Células-Madre Neurales/citología , Virus Zika/inmunología , Brasil , Cambodia , Células Cultivadas , Sistema Nervioso Central/patología , Sistema Nervioso Central/virología , Quimiocina CXCL10/líquido cefalorraquídeo , Quimiocina CXCL10/inmunología , Quimiocina CXCL9/líquido cefalorraquídeo , Quimiocina CXCL9/inmunología , Citocinas/análisis , Femenino , Perfilación de la Expresión Génica , Humanos , Lactante , Inflamación/inmunología , Inflamación/patología , Interferón-alfa/líquido cefalorraquídeo , Interferón-alfa/inmunología , Interferón beta/inmunología , Masculino , Microcefalia/patología , Embarazo , Complicaciones Infecciosas del Embarazo/virología , Replicación Viral/inmunología , Infección por el Virus Zika/inmunología
17.
PLoS Negl Trop Dis ; 13(3): e0007246, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30856223

RESUMEN

Laboratory confirmation of Zika virus (ZIKV) infection during pregnancy is challenging due to cross-reactivity with dengue virus (DENV) and limited knowledge about the kinetics of anti-Zika antibody responses during pregnancy. We described ZIKV and DENV serological markers and the maternal-fetal transfer of antibodies among mothers and neonates after the ZIKV microcephaly outbreak in Northeast Brazil (2016). We included 89 microcephaly cases and 173 neonate controls at time of birth and their mothers. Microcephaly cases were defined as newborns with a particular head circumference (2 SD below the mean). Two controls without microcephaly were matched by the expected date of delivery and area of residence. We tested maternal serum for recent (ZIKV genome, IgM and IgG3 anti-NS1) and previous (ZIKV and DENV neutralizing antibodies [NAbs]) markers of infection. Multiple markers of recent or previous ZIKV and DENV infection in mothers were analyzed using principal component analysis (PCA). At delivery, 5.6% of microcephaly case mothers and 1.7% of control mothers were positive for ZIKV IgM. Positivity for ZIKV IgG3 anti-NS1 was 8.0% for case mothers and 3.5% for control mothers. ZIKV NAbs was slightly higher among mothers of cases (69.6%) than that of mothers of controls (57.2%; p = 0.054). DENV exposure was detected in 85.8% of all mothers. PCA discriminated two distinct components related to recent or previous ZIKV infection and DENV exposure. ZIKV NAbs were higher in newborns than in their corresponding mothers (p<0.001). We detected a high frequency of ZIKV exposure among mothers after the first wave of the ZIKV outbreak in Northeast Brazil. However, we found low sensitivity of the serological markers to recent infection (IgM and IgG3 anti-NS1) in perinatal samples of mothers of microcephaly cases. Since the neutralization test cannot precisely determine the time of infection, testing for ZIKV immune status should be performed as early as possible and throughout pregnancy to monitor acute Zika infection in endemic areas.


Asunto(s)
Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Dengue/diagnóstico , Microcefalia/epidemiología , Microcefalia/etiología , Complicaciones Infecciosas del Embarazo/diagnóstico , Infección por el Virus Zika/diagnóstico , Adolescente , Adulto , Brasil/epidemiología , Estudios de Casos y Controles , Dengue/epidemiología , Virus del Dengue/inmunología , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Recién Nacido , Masculino , Embarazo , Complicaciones Infecciosas del Embarazo/epidemiología , Adulto Joven , Virus Zika/inmunología , Infección por el Virus Zika/complicaciones , Infección por el Virus Zika/epidemiología
18.
Science ; 363(6427): 607-610, 2019 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-30733412

RESUMEN

The clinical outcomes associated with Zika virus (ZIKV) in the Americas have been well documented, but other aspects of the pandemic, such as attack rates and risk factors, are poorly understood. We prospectively followed a cohort of 1453 urban residents in Salvador, Brazil, and, using an assay that measured immunoglobulin G3 (IgG3) responses against ZIKV NS1 antigen, we estimated that 73% of individuals were infected during the 2015 outbreak. Attack rates were spatially heterogeneous, varying by a factor of 3 within a community spanning 0.17 square kilometers. Preexisting high antibody titers to dengue virus were associated with reduced risk of ZIKV infection and symptoms. The landscape of ZIKV immunity that now exists may affect the risk for future transmission.


Asunto(s)
Anticuerpos Antivirales/sangre , Reacciones Cruzadas , Dengue/inmunología , Proteínas no Estructurales Virales/inmunología , Infección por el Virus Zika/inmunología , Adolescente , Adulto , Número Básico de Reproducción , Brasil , Niño , Brotes de Enfermedades , Femenino , Humanos , Inmunoglobulina G/sangre , Masculino , Estudios Prospectivos , Estudios Seroepidemiológicos , Población Urbana , Adulto Joven , Virus Zika
19.
PLoS Negl Trop Dis ; 12(10): e0006816, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30325933

RESUMEN

INTRODUCTION: Molecular xenomonitoring (MX)-pathogen detection in the mosquito rather than human-is a promising tool for lymphatic filariasis (LF) surveillance. In the Recife Metropolitan Region (RMR), the last LF focus in Brazil, Culex quinquefasciatus mosquitoes have been implicated in transmitting Wuchereria bancrofti parasites. This paper presents findings on the ideal mosquito collection method, mosquito dispersion, W. bancrofti infection in mosquitoes and W. bancrofti antigen in humans to aid MX development. METHODS: Experiments occurred within two densely populated urban areas of Olinda, RMR, in July and August 2015. U.S. Centers for Disease Control and Prevention (CDC) light traps were compared to battery-powered aspirators as collection methods, and mosquito dispersion was measured by mosquito mark release recapture (MMRR). Female Cx. quinquefasciatus were tested by PCR for W. bancrofti infection, and study area residents were screened by rapid tests for W. bancrofti antigen. RESULTS: Aspirators caught 2.6 times more total Cx. quinquefasciatus, including 38 times more blood-fed and 5 times more gravid stages, than CDC light traps. They also collected 123 times more Aedes aegypti. Of the 9,644 marked mosquitoes released, only ten (0.01%) were recaptured, nine of which were < 50m (34.8m median, 85.4m maximum) from the release point. Of 9,169 unmarked mosquitoes captured in the MMR, 38.3% were unfed, 48.8% blood-fed, 5.5% semi-gravid, and 7.3% gravid. PCR on 182 pools (1,556 mosquitoes) found no evidence of W. bancrofti infection in Cx. quinquefasciatus. Rapid tests on 110 of 111 eligible residents were all negative for W. bancrofti antigen. CONCLUSIONS: Aspirators were more effective than CDC light traps at capturing Ae. aegypti and all but unfed stages of Cx. quinquefasciatus. Female Cx. quinquefasciatus traveled short (< 86m) distances in this urban area. Lack of evidence for W. bancrofti infection in mosquitoes and antigen in humans in these fine-scale studies does not indicate that LF transmission has ceased in the RMR. A MX surveillance system should consider vector-specific collection methods, mosquito dispersion, and spatial scale but also local context, environmental factors such as sanitation, and host factors such as infection prevalence and treatment history.


Asunto(s)
Aedes/parasitología , Antígenos de Protozoos/sangre , Culex/parasitología , Filariasis Linfática/epidemiología , Entomología/métodos , Monitoreo Epidemiológico , Wuchereria bancrofti/aislamiento & purificación , Adulto , Aedes/crecimiento & desarrollo , Anciano , Anciano de 80 o más Años , Animales , Brasil/epidemiología , Estudios Cruzados , Culex/crecimiento & desarrollo , Transmisión de Enfermedad Infecciosa , Femenino , Humanos , Inmunoensayo , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Prevalencia , Población Urbana , Wuchereria bancrofti/genética
20.
BMC Infect Dis ; 18(1): 388, 2018 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-30097025

RESUMEN

BACKGROUND: Zika virus (ZIKV) is a recently emerged arbovirus, which infection during pregnancy is associated with a series of congenital malformations, collectively denominated Congenital Zika Syndrome (CZS). Following infection, ZIKV RNA has a median duration period of 10 days in plasma and up to 6 months in semen in immunocompetent adult individuals. Moreover, ZIKV is able to replicate and persist in fetal brains and placentas, consequently, infection is associated with pregnancy loss, albeit the pathogenic mechanisms are still unknown. CASE PRESENTATION: Here we report a CZS case of an infant born during the ZIKV outbreak in northeast Brazil, the child presented recurrent episodes of seizures with prolonged presence of ZIKV RNA on the central nervous system (CNS) and blood. ZIKV RNA was identified and partially sequenced from a sample of cerebrospinal fluid (CSF) obtained from the infant with 6 months of life, and later from another sample after the infant completed 17 months of life. Commonly congenital infections were discarded based on STORCH (syphilis, toxoplasmosis, rubella, cytomegalovirus and herpes simplex virus) negative laboratory results. Presence of specific ZIKV antibodies on both mother and children confirmed the association of severe microcephaly and ZIKV infection, diagnosed after birth. CONCLUSIONS: Altogether, our data raise the possibility that CZS cases may result in prolonged viral presence, these findings could be useful for therapy and diagnostic recommendations.


Asunto(s)
Microcefalia/virología , Infección por el Virus Zika/congénito , Infección por el Virus Zika/complicaciones , Adulto , Brasil , Epilepsia/etiología , Epilepsia/patología , Epilepsia/virología , Femenino , Humanos , Lactante , Recién Nacido , Microcefalia/patología , Embarazo , Complicaciones Infecciosas del Embarazo/virología , ARN Viral/aislamiento & purificación , Índice de Severidad de la Enfermedad , Virus Zika/genética , Virus Zika/aislamiento & purificación , Infección por el Virus Zika/diagnóstico , Infección por el Virus Zika/patología
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