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1.
Lancet Glob Health ; 12(7): e1129-e1138, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38876760

RESUMO

BACKGROUND: Data on long-term neurodevelopmental outcomes of normocephalic children (born with normal head circumference) exposed to Zika virus in utero are scarce. We aimed to compare neurodevelopmental outcomes in normocephalic children up to age 48 months with and without Zika virus exposure in utero. METHODS: In this prospective cohort study, we included infants from two cohorts of normocephalic children born in León and Managua, Nicaragua during the 2016 Zika epidemic. In León, all women pregnant during the two enrolment periods were eligible. In Managua, mother-child pairs were included from three districts in the municipality of Managua: all women who became pregnant before June 15, 2016, and had a due date of Sept 15, 2016 or later were eligible. Infants were serologically classified as Zika virus-exposed or Zika virus-unexposed in utero and were followed up prospectively until age 48 months. At 36 months and 48 months of age, the Mullen Scales of Early Learning (MSEL) assessment was administered. Primary outcomes were MSEL early learning composite (ELC) scores at 30-48 months in León and 36-48 months in Managua. We used an inverse probability weighting generalised estimating equations model to assess the effect of Zika virus exposure on individual MSEL cognitive domain scores and ELC scores, adjusted for maternal education and age, poverty status, and infant sex. FINDINGS: The initial enrolment period for the León cohort was between Jan 31 and April 5, 2017 and the second was between Aug 30, 2017, and Feb 22, 2018. The enrolment period for the Managua cohort was between Oct 24, 2019, and May 5, 2020. 478 mothers (482 infants) from the León cohort and 615 mothers (609 infants) from the Managua cohort were enrolled, of whom 622 children (303 from the León cohort; 319 from the Managua cohort) were included in the final analysis; four children had microcephaly at birth and thus were excluded from analyses, two from each cohort. 33 (11%) of 303 children enrolled in León and 219 (69%) of 319 children enrolled in Managua were exposed to Zika virus in utero. In both cohorts, no significant differences were identified in adjusted mean ELC scores between Zika virus-exposed and unexposed infants at 36 months (between-group difference 1·2 points [95% CI -4·2 to 6·5] in the León cohort; 2·8 [-2·4 to 8·1] in the Managua cohort) or at 48 months (-0·9 [-10·8 to 8·8] in the León cohort; 0·1 [-5·1 to 5·2] in the Managua cohort). No differences in ELC scores between Zika virus-exposed and unexposed infants exceeded 6 points at any time between 30 months and 48 months in León or between 36 months and 48 months in Managua, which was considered clinically significant in other settings. INTERPRETATION: We found no significant differences in neurodevelopmental scores between normocephalic children with in-utero Zika virus exposure and Zika virus-unexposed children at age 36 months or 48 months. These findings are promising, supporting typical neurodevelopment in Zika virus-exposed normocephalic children, although additional follow-up and research is warranted. FUNDING: National Institute of Child Health and Development, National Institute of Allergy and Infectious Diseases, and Fogarty International Center. TRANSLATION: For the Spanish translation of the abstract see Supplementary Materials section.


Assuntos
Desenvolvimento Infantil , Complicações Infecciosas na Gravidez , Efeitos Tardios da Exposição Pré-Natal , Infecção por Zika virus , Humanos , Nicarágua/epidemiologia , Infecção por Zika virus/epidemiologia , Feminino , Estudos Prospectivos , Pré-Escolar , Gravidez , Masculino , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Efeitos Tardios da Exposição Pré-Natal/virologia , Lactente , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/virologia , Zika virus , Adulto , Transtornos do Neurodesenvolvimento/epidemiologia , Transtornos do Neurodesenvolvimento/virologia
2.
Am J Trop Med Hyg ; 110(4): 724-730, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38377614

RESUMO

Since the Zika virus (ZIKV) pandemic in 2015-2017, there has been a near absence of reported cases in the Americas outside of Brazil. However, the conditions for Aedes-borne transmission persist in Latin America, and the threat of ZIKV transmission is increasing as population immunity wanes. Mexico has reported only 70 cases of laboratory-confirmed ZIKV infection since 2020, with no cases recorded in the Yucatán peninsula. Here, we provide evidence of active ZIKV transmission, despite the absence of official case reports, in the city of Mérida, Mexico, the capital of the state of Yucatán. Capitalizing on an existing cohort, we detected cases in participants with symptoms consistent with flavivirus infection from 2021 to 2022. Serum samples from suspected cases were tested for ZIKV RNA by polymerase chain reaction or ZIKV-reactive IgM by ELISA. To provide more specific evidence of exposure, focus reduction neutralization tests were performed on ELISA-positive samples. Overall, we observed 25 suspected ZIKV infections for an estimated incidence of 2.8 symptomatic cases per 1,000 persons per year. Our findings emphasize the continuing threat of ZIKV transmission in the setting of decreased surveillance and reporting.


Assuntos
Aedes , Infecção por Zika virus , Zika virus , Animais , Humanos , México/epidemiologia , América/epidemiologia
3.
Nat Commun ; 14(1): 2152, 2023 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-37185667

RESUMO

Heatwaves are becoming more frequent under climate change and can lead to thousands of excess deaths. Adaptation to extreme weather events often occurs in response to an event, with communities learning fast following unexpectedly impactful events. Using extreme value statistics, here we show where regional temperature records are statistically likely to be exceeded, and therefore communities might be more at-risk. In 31% of regions examined, the observed daily maximum temperature record is exceptional. Climate models suggest that similar behaviour can occur in any region. In some regions, such as Afghanistan and parts of Central America, this is a particular problem - not only have they the potential for far more extreme heatwaves than experienced, but their population is growing and increasingly exposed because of limited healthcare and energy resources. We urge policy makers in vulnerable regions to consider if heat action plans are sufficient for what might come.


Assuntos
Mudança Climática , Temperatura Alta , Temperatura , Afeganistão , América Central
4.
PLoS Negl Trop Dis ; 17(5): e0011275, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37205701

RESUMO

Knowledge regarding the frequency of ocular abnormalities and abnormal visual function in children exposed to Zika virus (ZIKV) in utero but born without congenital Zika syndrome (CZS) is limited. We hypothesized that children exposed to ZIKV in utero born without CZS may have visual impairments in early childhood. We performed ophthalmic examination between 16 and 21 months of age and neurodevelopment assessment at 24 months of age with the Mullen Scales of Early Learning test (MSEL) on children enrolled in a cohort born to women pregnant during and shortly after the ZIKV epidemic in Nicaragua (2016-2017). ZIKV exposure status was defined based on maternal and infant serological testing. Visual impairment was defined as abnormal if the child had an abnormal ophthalmic exam and/or low visual reception score in the MSEL assessment. Of 124 children included in the analysis, 24 (19.4%) were classified as ZIKV-exposed and 100 (80.6%) unexposed according to maternal or cord blood serology. Ophthalmic examination showed that visual acuity did not differ significantly between groups, thus, 17.4% of ZIKV-exposed and 5.2% of unexposed had abnormal visual function (p = 0.07) and 12.5% of the ZIKV-exposed and 2% of the unexposed had abnormal contrast testing (p = 0.05). Low MSEL visual reception score was 3.2-fold higher in ZIKV-exposed than unexposed children, but not statistically significant (OR 3.2, CI: 0.8-14.0; p = 0.10). Visual impairment (a composite measure of visual function or low MESL visual reception score) was present in more ZIKV-exposed than in unexposed children (OR 3.7, CI: 1.2, 11.0; p = 0.02). However, the limited sample size warrants future investigations to fully assess the impact of in utero ZIKV exposure on ocular structures and visual function in early childhood, even in apparently healthy children.


Assuntos
Complicações Infecciosas na Gravidez , Infecção por Zika virus , Zika virus , Lactente , Gravidez , Humanos , Criança , Pré-Escolar , Feminino , Infecção por Zika virus/complicações , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/diagnóstico , Complicações Infecciosas na Gravidez/epidemiologia , Nicarágua/epidemiologia , Transtornos da Visão/epidemiologia
5.
Viruses ; 15(3)2023 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-36992504

RESUMO

Objective: To understand the dynamics of Zika virus (ZIKV)-specific antibody immunity in children born to mothers in a flavivirus-endemic region during and after the emergence of ZIKV in the Americas. Methods: We performed serologic testing for ZIKV cross-reactive and type-specific IgG in two longitudinal cohorts, which enrolled pregnant women and their children (PW1 and PW2) after the beginning of the ZIKV epidemic in Nicaragua. Quarterly samples from children over their first two years of life and maternal blood samples at birth and at the end of the two-year follow-up period were studied. Results: Most mothers in this dengue-endemic area were flavivirus-immune at enrollment. ZIKV-specific IgG (anti-ZIKV EDIII IgG) was detected in 82 of 102 (80.4%) mothers in cohort PW1 and 89 of 134 (66.4%) mothers in cohort PW2, consistent with extensive transmission observed in Nicaragua during 2016. ZIKV-reactive IgG decayed to undetectable levels by 6-9 months in infants, whereas these antibodies were maintained in mothers at the year two time point. Interestingly, a greater contribution to ZIKV immunity by IgG3 was observed in babies born soon after ZIKV transmission. Finally, 43 of 343 (13%) children exhibited persistent or increasing ZIKV-reactive IgG at ≥9 months, with 10 of 30 (33%) tested demonstrating serologic evidence of incident dengue infection. Conclusions: These data inform our understanding of protective and pathogenic immunity to potential flavivirus infections in early life in areas where multiple flaviviruses co-circulate, particularly considering the immune interactions between ZIKV and dengue and the future possibility of ZIKV vaccination in women of childbearing potential. This study also shows the benefits of cord blood sampling for serologic surveillance of infectious diseases in resource-limited settings.


Assuntos
Vírus da Dengue , Dengue , Flavivirus , Infecção por Zika virus , Zika virus , Lactente , Recém-Nascido , Feminino , Humanos , Criança , Gravidez , Pré-Escolar , Nicarágua/epidemiologia , Anticorpos Antivirais , Imunoglobulina G , Reações Cruzadas
6.
Int J Infect Dis ; 122: 832-840, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35817285

RESUMO

OBJECTIVES: Aedes-borne viruses (ABV) affect humans on every inhabited continent and frequently cause epidemics. Recent epidemics of chikungunya and Zika viruses (ZIKV) highlight that preparedness for future epidemics requires assessment of susceptibility, particularly among high-risk groups. We sought to determine immunity against the three major circulating ABV among pregnant women in an ABV-endemic area of Colombia. METHODS: A cross-sectional seroprevalence study was performed, enrolling women presenting to Labor and Delivery. Cord blood and maternal peripheral blood samples were obtained. IgG seroprevalence to flaviviruses and chikungunya was determined by ELISA. An abbreviated neutralization test was used to estimate the frequency and magnitude of immunity to Zika and four dengue serotypes. Cluster analyses explored epidemiologic factors associated with seroprevalence. RESULTS: Most women exhibited high levels of neutralizing antibodies to one or more ABV; however, nearly 20% were seronegative for flaviviruses. Our research took place after the epidemic peak of the ZIKV outbreak in Colombia in 2016. However, only 20% of pregnant women had high levels of Zika-neutralizing antibodies consistent with likely protective immunity to ZIKV. CONCLUSION: Hence, a high proportion of pregnant women in Risaralda remain susceptible to one or more ABV including the teratogenic ZIKV, indicating a risk for future epidemics in this region.


Assuntos
Aedes , Febre de Chikungunya , Vírus da Dengue , Dengue , Infecção por Zika virus , Zika virus , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , Febre de Chikungunya/epidemiologia , Colômbia/epidemiologia , Estudos Transversais , Dengue/epidemiologia , Feminino , Humanos , Gravidez , Gestantes , Estudos Soroepidemiológicos
7.
Am J Trop Med Hyg ; 107(2): 296-299, 2022 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-35895398

RESUMO

Standard molecular detection of many pathogens, in particular RNA viruses, requires appropriate handling in the field for preserving the quality of the sample until processing. This could be challenging in remote tropical areas. Dengue virus (DENV), chikungunya virus (CHIKV), and Zika virus (ZIKV) are RNA viruses, prominent among the causes of fever in the tropics. We aimed to test the stability of arboviral RNA in contrived dried blood spots prepared on Whatman 903 Protein saver cards as a means of sample collection and storage. We were able to detect DENV, CHIKV, and ZIKV by real-time RT-PCR up to 180 days after card inoculation with stable Ct values across the study period. Our study supports dried blood spots (DBS) on protein saver cards as a platform for stable detection of arboviral RNA of sufficient quality to be used in diagnostic RT-PCR assays and next generation sequencing.


Assuntos
Febre de Chikungunya , Vírus Chikungunya , Vírus da Dengue , Dengue , Infecção por Zika virus , Zika virus , Humanos , Zika virus/genética , Febre de Chikungunya/diagnóstico , Infecção por Zika virus/diagnóstico , Dengue/diagnóstico , Vírus da Dengue/genética , Vírus Chikungunya/genética , RNA Viral/genética
8.
Lancet Infect Dis ; 22(8): 1210-1220, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35568049

RESUMO

BACKGROUND: Western (WEEV), eastern (EEEV), and Venezuelan (VEEV) equine encephalitis viruses are mosquito-borne pathogens classified as potential biological warfare agents for which there are currently no approved human vaccines or therapies. We aimed to evaluate the safety, tolerability, and immunogenicity of an investigational trivalent virus-like particle (VLP) vaccine, western, eastern, and Venezuelan equine encephalitis (WEVEE) VLP, composed of WEEV, EEEV, and VEEV VLPs. METHODS: The WEVEE VLP vaccine was evaluated in a phase 1, randomised, open-label, dose-escalation trial at the Hope Clinic of the Emory Vaccine Center at Emory University, Atlanta, GA, USA. Eligible participants were healthy adults aged 18-50 years with no previous vaccination history with an investigational alphavirus vaccine. Participants were assigned to a dose group of 6 µg, 30 µg, or 60 µg vaccine product and were randomly assigned (1:1) to receive the WEVEE VLP vaccine with or without aluminium hydroxide suspension (alum) adjuvant by intramuscular injection at study day 0 and at week 8. The primary outcomes were the safety and tolerability of the vaccine (assessed in all participants who received at least one administration of study product) and the secondary outcome was immune response measured as neutralising titres by plaque reduction neutralisation test (PRNT) 4 weeks after the second vaccination. This trial is registered at ClinicalTrials.gov, NCT03879603. FINDINGS: Between April 2, 2019, and June 13, 2019, 30 trial participants were enrolled (mean age 32 years, range 21-48; 16 [53%] female participants and 14 [47%] male participants). Six groups of five participants each received 6 µg, 30 µg, or 60 µg vaccine doses with or without adjuvant, and all 30 participants completed study follow-up. Vaccinations were safe and well tolerated. The most frequently reported symptoms were mild injection-site pain and tenderness (22 [73%] of 30) and malaise (15 [50%] of 30). Dose-dependent differences in the frequency of pain and tenderness were found between the 6 µg, 30 µg, and 60 µg groups (p=0·0217). No significant differences were observed between dosing groups for any other reactogenicity symptom. Two adverse events (mild elevated blood pressure and moderate asymptomatic neutropenia) were assessed as possibly related to the study product in one trial participant (60 µg dose with alum); both resolved without clinical sequelae. 4 weeks after second vaccine administration, neutralising antibodies were induced in all study groups with the highest response seen against all three vaccine antigens in the 30 µg plus alum group (PRNT80 geometric mean titre for EEEV 60·8, 95% CI 29·9-124·0; for VEEV 111·5, 49·8-249·8; and for WEEV 187·9, 90·0-392·2). Finally, 4 weeks after second vaccine administration, for all doses, the majority of trial participants developed an immune response to all three vaccine components (24 [83%] of 29 for EEEV; 26 [90%] of 29 for VEEV; 27 [93%] of 29 for WEEV; and 22 [76%] of 29 for EEEV, VEEV, and WEEV combined). INTERPRETATION: The favourable safety profile and neutralising antibody responses, along with pressing public health need, support further evaluation of the WEVEE VLP vaccine in advanced-phase clinical trials. FUNDING: The Vaccine Research Center of the National Institute of Allergy and Infectious Diseases, National Institutes of Health funded the clinical trial. The US Department of Defense contributed funding for manufacturing of the study product.


Assuntos
Alphavirus , Vírus da Encefalite Equina Venezuelana , Vacinas de Partículas Semelhantes a Vírus , Adjuvantes Imunológicos , Adulto , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , Método Duplo-Cego , Feminino , Cavalos , Humanos , Imunogenicidade da Vacina , Masculino , Pessoa de Meia-Idade , Dor , Adulto Jovem
9.
Trials ; 23(1): 185, 2022 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-35236394

RESUMO

BACKGROUND: Arboviruses transmitted by Aedes aegypti including dengue, Zika, and chikungunya are a major global health problem, with over 2.5 billion at risk for dengue alone. There are no licensed antivirals for these infections, and safe and effective vaccines are not yet widely available. Thus, prevention of arbovirus transmission by vector modification is a novel approach being pursued by multiple researchers. However, the field needs high-quality evidence derived from randomized, controlled trials upon which to base the implementation and maintenance of vector control programs. Here, we report the EVITA Dengue trial design (DMID 17-0111), which assesses the efficacy in decreasing arbovirus transmission of an innovative approach developed by the World Mosquito Program for vector modification of Aedes mosquitoes by Wolbachia pipientis. METHODS: DMID 17-0111 is a cluster-randomized trial in Belo Horizonte, Brazil, with clusters defined by primary school catchment areas. Clusters (n = 58) will be randomized 1:1 to intervention (release of Wolbachia-infected Aedes aegypti mosquitoes) vs. control (no release). Standard vector control activities (i.e., insecticides and education campaigns for reduction of mosquito breeding sites) will continue as per current practice in the municipality. Participants (n = 3480, 60 per cluster) are children aged 6-11 years enrolled in the cluster-defining school and living within the cluster boundaries who will undergo annual serologic surveillance for arboviral infection. The primary objective is to compare sero-incidence of arboviral infection between arms. DISCUSSION: DMID 17-0111 aims to determine the efficacy of Wolbachia-infected mosquito releases in reducing human infections by arboviruses transmitted by Aedes aegypti and will complement the mounting evidence for this method from large-scale field releases and ongoing trials. The trial also represents a critical step towards robustness and rigor for how vector control methods are assessed, including the simultaneous measurement and correlation of entomologic and epidemiologic outcomes. Data from this trial will inform further the development of novel vector control methods. TRIAL REGISTRATION: ClinicalTrials.gov NCT04514107 . Registered on 17 August 2020 Primary sponsor: National Institute of Health, National Institute of Allergy and Infectious Diseases.


Assuntos
Aedes , Vírus da Dengue , Dengue , Wolbachia , Infecção por Zika virus , Zika virus , Animais , Brasil/epidemiologia , Criança , Dengue/epidemiologia , Dengue/prevenção & controle , Humanos , Incidência , Mosquitos Vetores , Infecção por Zika virus/epidemiologia
10.
Am J Trop Med Hyg ; 105(4): 924-930, 2021 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-34370700

RESUMO

The American Zika virus (ZIKV) epidemic has highlighted the need to gain a better understanding of this emerging virus. The goal of this study was to describe the clinical symptoms, laboratory findings, and risk factors for symptomatic ZIKV infection in an area with ongoing transmission of other arboviral infections. We recruited patients at least 2 years of age seeking care at public health centers in León, Nicaragua, between January 2016 and August 2017, for fever, maculopapular rash, and/or nonsuppurative conjunctivitis with a duration of less than 1 week. A laboratory diagnosis of ZIKV was established using a combination of molecular and serological tests. Clinical and laboratory findings and potential risk factors were compared between participants with and without acute ZIKV infection. Fifty-eight (26%) of the 225 participants included in the analysis were found to have acute ZIKV infection. Pregnancy and reports of previous arboviral infection were associated with a higher risk of ZIKV infection. Rash, conjunctivitis, sore throat, and lower absolute neutrophil counts were associated with acute ZIKV infection. The clinical characteristics and risk factors identified were consistent with those identified by previous studies; however, we found sore throat to be a feature of ZIKV infection. We also found that neutrophil counts were lower in ZIKV-infected subjects. These clinical symptoms and laboratory data may help clinicians suspect ZIKV infection during future outbreaks.


Assuntos
Anticorpos Antivirais/sangue , Dengue/epidemiologia , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/patologia , Zika virus/imunologia , Adolescente , Adulto , Afinidade de Anticorpos , Especificidade de Anticorpos , Estudos de Casos e Controles , Criança , Dengue/diagnóstico , Dengue/patologia , Vírus da Dengue/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nicarágua/epidemiologia , Fatores de Tempo , Adulto Jovem , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/imunologia
12.
Clin Infect Dis ; 72(5): e146-e153, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33515459

RESUMO

BACKGROUND: Neurodevelopmental outcomes of asymptomatic children exposed to Zika virus (ZIKV) in utero are not well characterized. METHODS: We prospectively followed 129 newborns without evidence of congenital Zika syndrome (CZS) up to 24 months of age. Participants were classified as ZIKV exposed or ZIKV unexposed. The Mullen Scales of Early Learning (MSEL) was administered in the participants' homes at 6, 12, 15, 18, 21, and 24 months of age by trained psychologists. Sociodemographic data, medical history, and infant anthropometry at birth were collected at each home visit. Our primary outcome was the Mullen Early Learning Composite Score (ECL) at 24 months of age between our 2 exposure groups. Secondary outcomes were differences in MSEL subscales over time and at 24 months. RESULTS: Of 129 infants in whom exposure status could be ascertained, 32 (24.8%) met criteria for in utero ZIKV exposure and 97 (75.2%) did not. There were no differences in maternal age, maternal educational attainment, birthweight, or gestational age at birth between the 2 exposure groups. The adjusted means and standard errors (SEs) for the ELC score between the ZIKV-exposed children compared to ZIKV-unexposed children were 91.4 (SE, 3.1) vs 96.8 (SE, 2.4) at 12 months and 93.3 (SE, 2.9) vs 95.9 (SE, 2.3) at 24 months. In a longitudinal mixed model, infants born to mothers with an incident ZIKV infection (P = .01) and low-birthweight infants (<2500 g) (P = .006) had lower composite ECL scores. CONCLUSIONS: In this prospective cohort of children without CZS, children with in utero ZIKV exposure had lower neurocognitive scores at 24 months.


Assuntos
Complicações Infecciosas na Gravidez , Infecção por Zika virus , Zika virus , Criança , Feminino , Humanos , Lactente , Recém-Nascido , Nicarágua/epidemiologia , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Estudos Prospectivos , Infecção por Zika virus/epidemiologia
13.
Viruses ; 13(2)2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33494175

RESUMO

Zika virus (ZIKV) RNA has been found to remain in human semen for up to one year after infection, but the presence of Flavivirus antigens in the different compartments of semen has been largely unexplored. Following the introduction of ZIKV in Nicaragua (2016), a prospective study of patients with clinical symptoms consistent with ZIKV was conducted in León to investigate virus shedding in different fluids. ZIKV infection was confirmed in 16 male subjects (≥18 years of age) by RT-qPCR in either blood, saliva or urine. Of these, three provided semen samples at 7, 14, 21, 28, 60 and 180 days postsymptom onset (DPSO) for Flavivirus antigens and RNA studies. These cases were compared with 19 asymptomatic controls. Flavivirus antigens were examined by immunofluorescence (IF) using the 4G2 Mabs, and confocal microscopy was used to explore fluorescence patterns. The three (100%) symptomatic subjects and 3 (16%) of the 19 asymptomatic subjects had Flavivirus antigens and viral RNA in the spermatozoa fraction. The percentage of IF Flavivirus-positive spermatozoa cells ranged from 1.9% to 25% in specimens from symptomatic subjects, as compared with 0.8% to 3.8% in specimens from asymptomatic controls. A marked IF-pattern in the cytoplasmic droplets and tail of the spermatozoa was observed. The sperm concentrations (45 × 106/mL vs. 63.5 × 106/mL, p = 0.041) and the total motility percentage (54% vs. 75%, p = 0.009) were significantly lower in specimens from ZIKV-positive than in those of ZIKV-negative. In conclusion, this study demonstrated the presence of Flavivirus antigens and RNA within a time frame of 28 DPSO in sperm cells of symptomatic and asymptomatic subjects during the ZIKV epidemic. These findings have implications for public health, in terms of nonarthropod-born, silent transmission facilitated by sperm cells and potential transmission from asymptomatic males to pregnant women, with consequences to the fetus.


Assuntos
Antígenos Virais/análise , Flavivirus/isolamento & purificação , RNA Viral/análise , Espermatozoides/virologia , Infecção por Zika virus/virologia , Zika virus/isolamento & purificação , Adulto , Antígenos Virais/sangue , Antígenos Virais/urina , Flavivirus/genética , Imunofluorescência , Humanos , Masculino , RNA Viral/sangue , RNA Viral/urina , Reação em Cadeia da Polimerase em Tempo Real , Saliva/virologia , Sêmen/virologia , Espermatozoides/química , Eliminação de Partículas Virais , Adulto Jovem , Zika virus/genética
14.
Trials ; 21(1): 839, 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33032661

RESUMO

BACKGROUND: Current urban vector control strategies have failed to contain dengue epidemics and to prevent the global expansion of Aedes-borne viruses (ABVs: dengue, chikungunya, Zika). Part of the challenge in sustaining effective ABV control emerges from the paucity of evidence regarding the epidemiological impact of any Aedes control method. A strategy for which there is limited epidemiological evidence is targeted indoor residual spraying (TIRS). TIRS is a modification of classic malaria indoor residual spraying that accounts for Aedes aegypti resting behavior by applying residual insecticides on exposed lower sections of walls (< 1.5 m), under furniture, and on dark surfaces. METHODS/DESIGN: We are pursuing a two-arm, parallel, unblinded, cluster randomized controlled trial to quantify the overall efficacy of TIRS in reducing the burden of laboratory-confirmed ABV clinical disease (primary endpoint). The trial will be conducted in the city of Merida, Yucatan State, Mexico (population ~ 1million), where we will prospectively follow 4600 children aged 2-15 years at enrollment, distributed in 50 clusters of 5 × 5 city blocks each. Clusters will be randomly allocated (n = 25 per arm) using covariate-constrained randomization. A "fried egg" design will be followed, in which all blocks of the 5 × 5 cluster receive the intervention, but all sampling to evaluate the epidemiological and entomological endpoints will occur in the "yolk," the center 3 × 3 city blocks of each cluster. TIRS will be implemented as a preventive application (~ 1-2 months prior to the beginning of the ABV season). Active monitoring for symptomatic ABV illness will occur through weekly household visits and enhanced surveillance. Annual sero-surveys will be performed after each transmission season and entomological evaluations of Ae. aegypti indoor abundance and ABV infection rates monthly during the period of active surveillance. Epidemiological and entomological evaluation will continue for up to three transmission seasons. DISCUSSION: The findings from this study will provide robust epidemiological evidence of the efficacy of TIRS in reducing ABV illness and infection. If efficacious, TIRS could drive a paradigm shift in Aedes control by considering Ae. aegypti behavior to guide residual insecticide applications and changing deployment to preemptive control (rather than in response to symptomatic cases), two major enhancements to existing practice. TRIAL REGISTRATION: ClinicalTrials.gov NCT04343521 . Registered on 13 April 2020. The protocol also complies with the WHO International Clinical Trials Registry Platform (ICTRP) (Additional file 1). PRIMARY SPONSOR: National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIH/NIAID).


Assuntos
Aedes , Dengue , Inseticidas , Infecção por Zika virus , Zika virus , Animais , Criança , Dengue/diagnóstico , Dengue/epidemiologia , Dengue/prevenção & controle , Humanos , México/epidemiologia , Controle de Mosquitos , Mosquitos Vetores , Ensaios Clínicos Controlados Aleatórios como Assunto
15.
PLoS One ; 15(4): e0230692, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32243482

RESUMO

BACKGROUND: Zika virus caused thousands of congenital anomalies during a recent epidemic. Because Zika emerged in areas endemic for dengue and these related flaviviruses elicit cross-reactive antibodies, it is challenging to serologically monitor pregnant women for Zika infection. METHODS: A prospective cohort of 253 pregnant women was established in León, Nicaragua. Women were followed during prenatal care through delivery. Serologic specimens were obtained at each visit, and birth outcome was recorded. Established flavivirus serologic methods were adapted to determine Zika seroprevalence, and a stepwise testing algorithm estimated timing of Zika infection in relation to pregnancy. RESULTS: Zika seroprevalence was approximately 59% among women tested. Neutralization testing was highly concordant with Zika NS1 BOB results. Per study algorithm, 21% (40/187) of women were classified as experiencing Incident ZIKV infection during pregnancy. Importantly, the Incident ZIKV group included mostly women pregnant during the 2016 Zika epidemic peak and the only 3 subjects in the cohort with RT-PCR-confirmed infections. Approximately 17% of births had complications; 1.5% (3/194) manifesting clinical criteria of congenital Zika syndrome, one was RT-PCR-confirmed as a case of congenital Zika syndrome. Adverse birth outcome did not correlate with timing of Zika infection. CONCLUSIONS: By leveraging prenatal care systems, we developed a simple algorithm for identifying women who were likely infected by Zika during pregnancy.


Assuntos
Epidemias , Monitoramento Epidemiológico , Mães , Testes Sorológicos , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/imunologia , Adolescente , Adulto , Estudos de Coortes , Feminino , Humanos , Nicarágua/epidemiologia , Gravidez , Estudos Prospectivos , Fatores de Tempo , Adulto Jovem
16.
Emerg Infect Dis ; 25(4): 808-810, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30882329

RESUMO

Zika virus, an arthropod-borne flavivirus pathogen in humans, is unusual because it can be sexually transmitted and can be shed for prolonged periods in semen. We report viral shedding in vaginal secretions for up to 6 months, indicating the potential for sexual and vertical transmission by infected women.


Assuntos
RNA Viral/isolamento & purificação , Eliminação de Partículas Virais , Infecção por Zika virus/transmissão , Zika virus/isolamento & purificação , Feminino , Humanos , Transmissão Vertical de Doenças Infecciosas , Nicarágua , Vagina/virologia , Infecção por Zika virus/virologia
17.
Travel Med Infect Dis ; 25: 20-25, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29894797

RESUMO

BACKGROUND: Zika virus (ZIKV) infection has emerged as a significant threat for pregnant women and newborns in populations living in or visiting Latin America. We previously reported a preliminary analysis in Sucre, Colombia, as the first group of pregnant women with RT-PCR-confirmed ZIKV (ZIKa enEmbarazadas yReciénNacidos enCOLombia, ZIKERNCOL). METHODS: In this second report, findings of the first 86 pregnant women from La Virginia and Dosquebradas (municipalities), Risaralda, Colombia, with RT-PCR-confirmed ZIKV infection are reported. Clinical, demographical and obstetrical findings are described. RESULTS: All women reported ZIKV symptoms during pregnancy: 79.1% rash, 55.8% fever, among others. In addition to ZIKV, RT-PCR was positive for dengue in 18.6%; 45.3% Dengue IgM+; 5.8% RT-PCR positive for chikungunya; 3.6% Chikungunya IgM+. STORCH screening in mother: 11.6% IgG + anti-Toxoplasma gondii, 6% IgG + anti-rubella, 4.7% IgG + CMV. The rest of STORCH tests were negative. Microcephaly was observed in 2.4% of the newborns. No calcifications or other CNS alterations were detected. One newborn had cleft palate and one had bilateral renal ectopy. CONCLUSIONS: The rate of microcephaly in our cohort was consistent with other studies. Pregnant women in endemic areas should be followed and tested according to standard protocols, and asymptomatic ZIKV infection should be considered. Long-term follow-up of children is required in the congenital Zika syndrome (CZS) assessment.


Assuntos
Complicações Infecciosas na Gravidez/virologia , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/epidemiologia , Adolescente , Adulto , Anticorpos Antivirais , Febre de Chikungunya/imunologia , Estudos de Coortes , Colômbia/epidemiologia , Dengue/diagnóstico , Dengue/imunologia , Feminino , Humanos , Imunoglobulina G , Recém-Nascido , Microcefalia/virologia , Gravidez , Estudos Retrospectivos , Rubéola (Sarampo Alemão)/imunologia , Toxoplasmose , Adulto Jovem
18.
Nature ; 522(7554): 81-4, 2015 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-25799987

RESUMO

No large group of recently extinct placental mammals remains as evolutionarily cryptic as the approximately 280 genera grouped as 'South American native ungulates'. To Charles Darwin, who first collected their remains, they included perhaps the 'strangest animal[s] ever discovered'. Today, much like 180 years ago, it is no clearer whether they had one origin or several, arose before or after the Cretaceous/Palaeogene transition 66.2 million years ago, or are more likely to belong with the elephants and sirenians of superorder Afrotheria than with the euungulates (cattle, horses, and allies) of superorder Laurasiatheria. Morphology-based analyses have proved unconvincing because convergences are pervasive among unrelated ungulate-like placentals. Approaches using ancient DNA have also been unsuccessful, probably because of rapid DNA degradation in semitropical and temperate deposits. Here we apply proteomic analysis to screen bone samples of the Late Quaternary South American native ungulate taxa Toxodon (Notoungulata) and Macrauchenia (Litopterna) for phylogenetically informative protein sequences. For each ungulate, we obtain approximately 90% direct sequence coverage of type I collagen α1- and α2-chains, representing approximately 900 of 1,140 amino-acid residues for each subunit. A phylogeny is estimated from an alignment of these fossil sequences with collagen (I) gene transcripts from available mammalian genomes or mass spectrometrically derived sequence data obtained for this study. The resulting consensus tree agrees well with recent higher-level mammalian phylogenies. Toxodon and Macrauchenia form a monophyletic group whose sister taxon is not Afrotheria or any of its constituent clades as recently claimed, but instead crown Perissodactyla (horses, tapirs, and rhinoceroses). These results are consistent with the origin of at least some South American native ungulates from 'condylarths', a paraphyletic assembly of archaic placentals. With ongoing improvements in instrumentation and analytical procedures, proteomics may produce a revolution in systematics such as that achieved by genomics, but with the possibility of reaching much further back in time.


Assuntos
Colágeno Tipo I/química , Fósseis , Mamíferos/classificação , Filogenia , Sequência de Aminoácidos , Animais , Osso e Ossos/química , Bovinos , Colágeno Tipo I/genética , Feminino , Perissodáctilos/classificação , Placenta , Gravidez , Proteômica , América do Sul
19.
PLoS One ; 9(4): e93854, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24718458

RESUMO

Isotopic and molecular analysis on human, fauna and pottery remains can provide valuable new insights into the diets and subsistence practices of prehistoric populations. These are crucial to elucidate the resilience of social-ecological systems to cultural and environmental change. Bulk collagen carbon and nitrogen isotopic analysis of 82 human individuals from mid to late Holocene Brazilian archaeological sites (∼6,700 to ∼1,000 cal BP) reveal an adequate protein incorporation and, on the coast, the continuation in subsistence strategies based on the exploitation of aquatic resources despite the introduction of pottery and domesticated plant foods. These results are supported by carbon isotope analysis of single amino acid extracted from bone collagen. Chemical and isotopic analysis also shows that pottery technology was used to process marine foods and therefore assimilated into the existing subsistence strategy. Our multidisciplinary results demonstrate the resilient character of the coastal economy to cultural change during the late Holocene in southern Brazil.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Aminoácidos/metabolismo , Animais , Apatitas/metabolismo , Arqueologia , Teorema de Bayes , Osso e Ossos/metabolismo , Brasil , Isótopos de Carbono , Cerâmica , Colágeno/metabolismo , Geografia , Humanos , Marcação por Isótopo , Lipídeos/isolamento & purificação , Isótopos de Nitrogênio , Fatores de Tempo
20.
Nature ; 453(7192): 212-5, 2008 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-18464740

RESUMO

The Amazon rainforest plays a crucial role in the climate system, helping to drive atmospheric circulations in the tropics by absorbing energy and recycling about half of the rainfall that falls on it. This region (Amazonia) is also estimated to contain about one-tenth of the total carbon stored in land ecosystems, and to account for one-tenth of global, net primary productivity. The resilience of the forest to the combined pressures of deforestation and global warming is therefore of great concern, especially as some general circulation models (GCMs) predict a severe drying of Amazonia in the twenty-first century. Here we analyse these climate projections with reference to the 2005 drought in western Amazonia, which was associated with unusually warm North Atlantic sea surface temperatures (SSTs). We show that reduction of dry-season (July-October) rainfall in western Amazonia correlates well with an index of the north-south SST gradient across the equatorial Atlantic (the 'Atlantic N-S gradient'). Our climate model is unusual among current GCMs in that it is able to reproduce this relationship and also the observed twentieth-century multidecadal variability in the Atlantic N-S gradient, provided that the effects of aerosols are included in the model. Simulations for the twenty-first century using the same model show a strong tendency for the SST conditions associated with the 2005 drought to become much more common, owing to continuing reductions in reflective aerosol pollution in the Northern Hemisphere.


Assuntos
Aerossóis/análise , Desastres/estatística & dados numéricos , Ecossistema , Poluição Ambiental/estatística & dados numéricos , Efeito Estufa , Modelos Teóricos , Árvores/fisiologia , Oceano Atlântico , Dióxido de Carbono/análise , Desastres/história , História do Século XX , História do Século XXI , Oceano Pacífico , Probabilidade , Chuva , Estações do Ano , América do Sul , Temperatura
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