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1.
J Infect Dis ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38912968

RESUMO

BACKGROUND: The mechanisms that mediate immune protection in individuals with subclinical (SC) or asymptomatic infection with L. braziliensis are largely unknown. Neutrophils (PMNs) have been implicated in progressive symptomatic cutaneous leishmaniasis (CL), but their potential participation in maintenance of subclinical infection is unexplored. The aim of this study was to compare the phenotypic and functional profiles of PMNs in individuals with SC infection versus patients with symptomatic CL due to L. braziliensis. METHODS: Subjects were recruited in the endemic region of Corte de Pedra, Bahia, Brazil. Surface markers to define activation status were characterized by flow cytometry. Functional responses of PMNs including phagocytic capacity, production of oxidative species, and oxidative killing of intracellular parasites were studied in vitro. RESULTS: PMNs from individuals with SC infection displayed a more activated phenotype and greater ability to control the infection than PMNs from patients with CL. In contrast, PMNs from patients with CL exhibited higher expression of HLA-DR and higher production of oxidative species than PMNs from subjects with SC infection. CONCLUSION: PMNs from individuals with SC infection can control the infection more efficiently than PMNs from patients with CL, despite the lower production of oxidants. Our observations suggest that L. braziliensis may evade microbicidal mechanisms of PMNs from patients with CL, contributing to parasite dissemination and the establishment of disease.

2.
Malar J ; 23(1): 272, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39256754

RESUMO

BACKGROUND: Reactive case detection (RCD) aims to reduce malaria transmission stemming from asymptomatic carriers. Symptomatic individuals diagnosed with malaria at a health centre are followed to their households, where members of the index case and neighbouring households are tested and treated for malaria. An RCD programme was tested in the Ashanti region of Ghana in order to study diagnostic accuracy in the hospital and household settings, assess the prevalence of subclinical infections and possible clustering in index case households, and identify operational challenges for future RCD programmes. Currently, transmission in this region is high, but reactive interventions might become an option once transmission is reduced. METHODS: 264 febrile individuals were enrolled at the Mankranso Government Hospital and tested for malaria using rapid diagnostic tests (RDT). From the pool of RDT-positive febrile index cases, 14 successful RCD follow-ups were conducted, and 233 individuals were enrolled from the index case, neighbour, and control households. The sensitivity of diagnostic tools for clinical and subclinical cases was compared, including RDT, expert microscopy by World Health Organization-certified microscopists, field microscopy, and qPCR. RESULTS: Poor diagnosis and low receptivity to RCD-style follow-ups were major limitations to a successful and effective RCD programme. Field microscopy detected only 49% of clinical infections compared to RDT. 54% of individuals did not agree to a follow-up, and 66% of attempted follow-ups failed. The system effectiveness of RCD, calculated as the product of correctly diagnosed index cases, successful follow-ups, and proportion of asymptomatic infections detected by RDT, was very low at 4.0%. CONCLUSIONS: Due to low system effectiveness and the endemic nature of the disease setting in which asymptomatic prevalence is high and infections are not clustered around index case households, RCD is currently not a feasible option for malaria control in this region. The operational challenges identified through this study may help inform future reactive intervention programme designs once transmission is reduced.


Assuntos
Infecções Assintomáticas , Testes Diagnósticos de Rotina , Malária Falciparum , Gana/epidemiologia , Humanos , Malária Falciparum/diagnóstico , Malária Falciparum/epidemiologia , Malária Falciparum/prevenção & controle , Infecções Assintomáticas/epidemiologia , Feminino , Masculino , Pré-Escolar , Criança , Adolescente , Testes Diagnósticos de Rotina/métodos , Testes Diagnósticos de Rotina/estatística & dados numéricos , Adulto , Adulto Jovem , Lactente , Pessoa de Meia-Idade , Plasmodium falciparum/isolamento & purificação , Prevalência , Sensibilidade e Especificidade , Idoso
3.
J Med Virol ; 95(2): e28517, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36680415

RESUMO

This study investigated outcomes of children born to women who seroconverted to rubella immune during pregnancy. In a prior 2012-2013 study of 296 women who were rubella nonimmune, 26 (8.8%) seroconverted to rubella immune during pregnancy. These same women and their now 8-9 years-old children were queried as to the children's developmental health. After removing exclusions and those lost to follow-up, the total response rate was 115/204 (56.4%). Three sets of twins in the nonimmune group increased the total to 118. The seroconversion group had more autism (12.5% vs. 3.9%, p = 0.19), ADHD (37.5% vs. 18.6%, p = 0.10), and any developmental disability (43.8% vs. 31.4%, p = 0.39) but none showed a statistical difference between the two groups. Compared to Autism and Developmental Disabilities Monitoring data, the seroconversion group had a greater prevalence of autism (odds ratio [OR] 6.07, p = 0.051, nonsignificant); and to data derived from the National Health Interview Survey, a nonsignificant higher odds of autism (OR 5.57, p = 0.060), higher odds of ADHD (OR 5.65, p = 0.0027) and of any developmental disability (OR 3.59, p = 0.014). The nonimmune group also demonstrated a statistically significant increase for both ADHD and any developmental disability, but not for autism.


Assuntos
Transtorno Autístico , Rubéola (Sarampo Alemão) , Gravidez , Humanos , Criança , Feminino , Prevalência , Fatores de Risco , Inquéritos e Questionários
4.
Malar J ; 22(1): 180, 2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37291561

RESUMO

BACKGROUND: The reliance on blood for thin and thick blood smear microscopy-using a relatively invasive procedure has presented challenges to the use of reliable diagnostic tests in non-clinical settings at the point-of-need (PON). To improve the capacity of non-blood-based rapid diagnostic tests to confirm subclinical infections, and thereby identify and quantify the human reservoir at the PON, a cross-sectoral collaboration between university researchers and commercial partners produced an innovative, non-invasive saliva-based RDT capable of identifying novel, non-hrp2/3 parasite biomarkers. While this new saliva-based malaria asymptomatic and asexual rapid test (SMAART-1) shows increased detection sensitivity and precision potential by identifying a new P. falciparum protein marker (PSSP17), appraising its utility in the field-particularly with respect to its adoption potential with children and adults in high risk, endemic regions-is necessary to warrant its continued development. METHODS: The purpose of this study was to assess the acceptability and adoption potential of the SMAART-1 at select PON sites in the Kinshasa Province. Teachers, community health workers, nurses, and laboratory technicians participated in data collection at three distinct community sites in Kinshasa Province, Democratic Republic of the Congo. Three data collection methods were utilized in this mixed methods study to provide an overarching acceptability evaluation of the SMAART-1 at PON field sites: observation checklists of SMAART-1 implementation, focus group discussions, and surveys with local health care practitioners-particularly teachers and community health workers. RESULTS: Findings indicate participants were interested in and supportive of the SMAART-1 protocol, with approximately 99% of the participants surveyed indicating that they either "agreed" or "strongly agreed" with the statement that they "would use the saliva-based malaria asymptomatic rapid test as part of a community malaria detection and treatment programme." Data also suggest that the protocol was broadly appealing for its testing sensitivity and ease of use. CONCLUSIONS: The SMAART-1 protocol's clinically reliable results demonstrate a promising new level of sensitivity and precision for detecting parasite biomarkers. This study's mixed-methods assessment of the protocol's utility and adoption potential in the field, with a target user audience, advances its development and points to opportunities to formalize and expand evaluation efforts.


Assuntos
Malária Falciparum , Malária , Parasitos , Adulto , Criança , Animais , Humanos , Saliva , República Democrática do Congo/epidemiologia , Testes Diagnósticos de Rotina/métodos , Malária/diagnóstico , Malária/tratamento farmacológico , Inquéritos e Questionários , Biomarcadores , Malária Falciparum/epidemiologia , Plasmodium falciparum
5.
J Infect Dis ; 226(10): 1800-1808, 2022 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-35478039

RESUMO

On influenza virus infection or vaccination, immune responses occur, including the production of antibodies with various functions that contribute to protection from seasonal influenza virus infection. In the current study, we attempted to identify the antibody functions that play a central role in preventing the onset of seasonal influenza by comparing the levels of several antibody titers for different antibody functions between 5 subclinically infected individuals and 16 patients infected with seasonal H3N2 virus. For antibody titers before influenza virus exposure, we found that the nAb titers and enzyme-linked immunosorbent assay titers against hemagglutinin and neuraminidase (NA) proteins in the subclinically infected individuals were significantly higher than those in the patients, whereas the NA inhibition titers and antibody-dependent cellular cytotoxicity activities did not significantly differ between subclinically infected individuals and infected patients. These results suggest that nAb and enzyme-linked immunosorbent assay titers against hemagglutinin and NA serve as correlates of symptomatic influenza infection.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Vacinas contra Influenza , Influenza Humana , Humanos , Vírus da Influenza A Subtipo H3N2 , Hemaglutininas , Estações do Ano , Anticorpos Antivirais , Neuraminidase , Glicoproteínas de Hemaglutininação de Vírus da Influenza
6.
Microb Pathog ; 150: 104725, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33400985

RESUMO

Leprosy, also known as Hansen's disease, is a long-term infection by the bacteria Mycobacterium leprae, and actually still persists as a serious public health problem. The clinical parameters are used for diagnosis, however, some studies have indicated the selection of a set of biomarkers of subclinical infection, both serological and cellular, that allow the early diagnosis. Some cytokines and chemokines have been differentially expressed in index cases (paucibacillary and multibacillary patients) and household contacts (HHC), and may present a potential biomarker of M. leprae subclinical infection. Thus, the aim of this study was to analyze the variations in the profile of cytokines and chemokines, longitudinally, between index cases and their household contacts with a view to identifying possible biomarkers with differential expression, which may guide the early subclinical infection in household contacts. A longitudinal study was carried out between 2014 and 2015. The serum levels of the cytokines and chemokines were measured in all patient samples by CBA (Cytometric Bead Array). We observed a reduction of IL-4 and IL-17 expression of HHC group in the second evaluation (T1), as also a reduction of IL-17 in MB. We observed increased expression of IL-2 in PB patients as well. HHC, PB and MB showed a similar reduction profile of the chemokines CXCL8, CXCL9 and CXCL10 from T0 to T1. Interestingly, only serological levels of CCL2 are increased after a follow-up of HHC group, and this group, but not PB and MB patients, showed a significant association and a negative correlation between CCL2 and IFN-γ. The present study showed for the first time a similarity in the immunological scenario between HHC, PB and MB patients. In addition, this work highlights CCL2 chemokine in association with IFN-γ as possible biomarkers of subclinical infection of HHC, as also a parameter of early infection monitoring.


Assuntos
Infecções Assintomáticas , Interferon gama , Hanseníase , Antígenos de Bactérias , Biomarcadores/sangue , Quimiocina CCL2 , Humanos , Interferon gama/sangue , Estudos Longitudinais , Mycobacterium leprae
7.
Niger J Med ; 30(6): 631-636, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-37908370

RESUMO

The aetiologic agent of COVID-19 is a novel coronavirus, SARS-CoV-2. Like other coronaviruses, it generally induces enteric and respiratory diseases in animals and humans. COVID-19 may be subclinical, and symptomatic, ranging from mild-to-severe disease. The spectrum of presentation is the result of several factors ranging from the inoculum size, inherent host susceptibility, possible cross-reacting circulating antibodies. Subclinical viral infections are associated with widespread community transmission and in some cases like Polio, herd immunity. An understanding of the biology and immune behavior in subclinical coronavirus disease 2019 (COVID-19) might be useful in the quest for vaccine development as well as the current control efforts against the COVID-19 pandemic. We carried out a narrative review of the available literature on the biology, etiopathogenesis, clinical manifestation of SARS-CoV-2 viral infection, focusing on our current understanding of the disease mechanisms and its clinical manifestation, and the host immune response to the infection. We also highlighted some of the research gaps regarding subclinical infection in COVID-19 and its potential application for vaccine development and other preventive efforts toward containing the current COVID-19 pandemic.

8.
J Virol ; 93(2)2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30333177

RESUMO

Herpes simplex virus 2 (HSV-2) is a common sexually transmitted infection with a highly variable clinical course. Many infections quickly become subclinical, with episodes of spontaneous virus reactivation. To study host-HSV-2 interactions, an animal model of subclinical HSV-2 infection is needed. In an effort to develop a relevant model, rhesus macaques (RM) were inoculated intravaginally with two or three HSV-2 strains (186, 333, and/or G) at a total dose of 1 × 107 PFU of HSV-2 per animal. Infectious HSV-2 and HSV-2 DNA were consistently shed in vaginal swabs for the first 7 to 14 days after each inoculation. Proteins associated with wound healing, innate immunity, and inflammation were significantly increased in cervical secretions immediately after HSV-2 inoculation. There was histologic evidence of acute herpesvirus pathology, including acantholysis in the squamous epithelium and ballooning degeneration of and intranuclear inclusion bodies in epithelial cells, with HSV antigen in mucosal epithelial cells and keratinocytes. Further, an intense inflammatory infiltrate was found in the cervix and vulva. Evidence of latent infection and reactivation was demonstrated by the detection of spontaneous HSV-2 shedding post-acute inoculation (102 to 103 DNA copies/swab) in 80% of RM. Further, HSV-2 DNA was detected in ganglia in most necropsied animals. HSV-2-specifc T-cell responses were detected in all animals, although antibodies to HSV-2 were detected in only 30% of the animals. Thus, HSV-2 infection of RM recapitulates many of the key features of subclinical HSV-2 infection in women but seems to be more limited, as virus shedding was undetectable more than 40 days after the last virus inoculation.IMPORTANCE Herpes simplex virus 2 (HSV-2) infects nearly 500 million persons globally, with an estimated 21 million incident cases each year, making it one of the most common sexually transmitted infections (STIs). HSV-2 is associated with increased human immunodeficiency virus type 1 (HIV-1) acquisition, and this risk does not decline with the use of antiherpes drugs. As initial acquisition of both HIV and HSV-2 infections is subclinical, study of the initial molecular interactions of the two agents requires an animal model. We found that HSV-2 can infect RM after vaginal inoculation, establish latency in the nervous system, and spontaneously reactivate; these features mimic some of the key features of HSV-2 infection in women. RM may provide an animal model to develop strategies to prevent HSV-2 acquisition and reactivation.


Assuntos
Acantólise/virologia , Herpes Simples/virologia , Herpesvirus Humano 2/patogenicidade , Vagina/virologia , Acantólise/imunologia , Acantólise/veterinária , Animais , Modelos Animais de Doenças , Feminino , Herpes Simples/imunologia , Herpes Simples/veterinária , Herpesvirus Humano 2/imunologia , Humanos , Macaca mulatta , Linfócitos T/imunologia , Latência Viral , Eliminação de Partículas Virais
9.
Am J Kidney Dis ; 76(4): 490-499.e1, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32628990

RESUMO

RATIONALE & OBJECTIVE: Patients receiving maintenance hemodialysis (MHD) are highly vulnerable to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The current study was designed to evaluate the prevalence of SARS-CoV-2 infection based on both nucleic acid testing (NAT) and antibody testing in Chinese patients receiving MHD. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: From December 1, 2019, to March 31, 2020, a total of 1,027 MHD patients in 5 large hemodialysis centers in Wuhan, China, were enrolled. Patients were screened for SARS-CoV-2 infection by symptoms and initial computed tomography (CT) of the chest. If patients developed symptoms after the initial screening was negative, repeat CT was performed. Patients suspected of being infected with SARS-CoV-2 were tested with 2 consecutive throat swabs for viral RNA. In mid-March 2020, antibody testing for SARS-CoV-2 was obtained for all MHD patients. EXPOSURE: NAT and antibody testing results for SARS-CoV-2. OUTCOMES: Morbidity, clinical features, and laboratory and radiologic findings. ANALYTICAL APPROACH: Differences between groups were examined using t test or Mann-Whitney U test, comparing those not infected with those infected and comparing those with infection detected using NAT with those with infection detected by positive serology test results. RESULTS: Among 1,027 patients receiving MHD, 99 were identified as having SARS-CoV-2 infection, for a prevalence of 9.6%. Among the 99 cases, 52 (53%) were initially diagnosed with SARS-CoV-2 infection by positive NAT; 47 (47%) were identified later by positive immunoglobulin G (IgG) or IgM antibodies against SARS-CoV-2. There was a spectrum of antibody profiles in these 47 patients: IgM antibodies in 5 (11%), IgG antibodies in 35 (74%), and both IgM and IgG antibodies in 7 (15%). Of the 99 cases, 51% were asymptomatic during the epidemic; 61% had ground-glass or patchy opacities on CT of the chest compared with 11.6% among uninfected patients (P<0.001). Patients with hypertensive kidney disease were more often found to have SARS-CoV-2 infection and were more likely to be symptomatic than patients with another primary cause of kidney failure. LIMITATIONS: Possible false-positive and false-negative results for both NAT and antibody testing; possible lack of generalizability to other dialysis populations. CONCLUSIONS: Half the SARS-CoV-2 infections in patients receiving MHD were subclinical and were not identified by universal CT of the chest and selective NAT. Serologic testing may help evaluate the overall prevalence and understand the diversity of clinical courses among patients receiving MHD who are infected with SARS-CoV-2.


Assuntos
Anticorpos Antivirais/análise , Betacoronavirus/imunologia , Infecções por Coronavirus/diagnóstico , Falência Renal Crônica/terapia , Pneumonia Viral/diagnóstico , Diálise Renal , COVID-19 , China/epidemiologia , Comorbidade , Infecções por Coronavirus/epidemiologia , Estudos Transversais , Feminino , Humanos , Falência Renal Crônica/epidemiologia , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/epidemiologia , Prevalência , Estudos Retrospectivos , SARS-CoV-2 , Testes Sorológicos/métodos , Tomografia Computadorizada por Raios X
10.
Acta Neuropathol ; 139(6): 965-976, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32232565

RESUMO

Widespread dietary exposure of the population of Britain to bovine spongiform encephalopathy (BSE) prions in the 1980s and 1990s led to the emergence of variant Creutzfeldt-Jakob Disease (vCJD) in humans. Two previous appendectomy sample surveys (Appendix-1 and -2) estimated the prevalence of abnormal prion protein (PrP) in the British population exposed to BSE to be 237 per million and 493 per million, respectively. The Appendix-3 survey was recommended to measure the prevalence of abnormal PrP in population groups thought to have been unexposed to BSE. Immunohistochemistry for abnormal PrP was performed on 29,516 samples from appendices removed between 1962 and 1979 from persons born between 1891 through 1965, and from those born after 1996 that had been operated on from 2000 through 2014. Seven appendices were positive for abnormal PrP, of which two were from the pre-BSE-exposure era and five from the post BSE-exposure period. None of the seven positive samples were from appendices removed before 1977, or in patients born after 2000 and none came from individuals diagnosed with vCJD. There was no statistical difference in the prevalence of abnormal PrP across birth and exposure cohorts. Two interpretations are possible. Either there is a low background prevalence of abnormal PrP in human lymphoid tissues that may not progress to vCJD. Alternatively, all positive specimens are attributable to BSE exposure, a finding that would necessitate human exposure having begun in the late 1970s and continuing through the late 1990s.


Assuntos
Síndrome de Creutzfeldt-Jakob/epidemiologia , Encefalopatia Espongiforme Bovina/epidemiologia , Proteínas Priônicas/metabolismo , Príons/metabolismo , Animais , Apêndice/metabolismo , Encéfalo/metabolismo , Encéfalo/virologia , Bovinos , Síndrome de Creutzfeldt-Jakob/metabolismo , Encefalopatia Espongiforme Bovina/metabolismo , Humanos , Prevalência
11.
J Infect Chemother ; 26(12): 1294-1300, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32958395

RESUMO

OBJECTIVES: We investigated relationships between subclinical COVID-19 (coronavirus disease 2019) and background factors. METHODS: We determined SARS-CoV-2 antibody (IgG) prevalence in 1603 patients, doctors, and nurses in 65 medical institutions in Kanagawa Prefecture, Japan and investigated their background factors. Antibodies (IgG) against SARS-CoV-2 were analyzed by Immunochromatographic test. RESULTS: The 39 subjects (2.4%) were found to be IgG antibody-positive: 29 in the patient group (2.9%), 10 in the doctor/nurse group (2.0%), and 0 in the control group. After adjustment for age, sex, and the antibody prevalence in the control group, antibody prevalence was 2.7% in the patient group and 2.1% in the doctor/nurse group. There was no significant difference between the antibody-positive subjects and the antibody-negative subjects in any background factors investigated including overseas travel, contact with overseas travelers, presence/absence of infected individuals in the living area, use of trains 5 times a week or more, BCG vaccination, and use of ACE inhibitor and ARB. CONCLUSIONS: Antibody prevalence in the present survey at medical institution is higher than that in Tokyo and in Osaka measured by the government suggesting that subclinical infections are occurring more frequently than expected. No background factor that influenced antibody-positive status due to subclinical infection was identified.


Assuntos
Infecções Assintomáticas/epidemiologia , Betacoronavirus/imunologia , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Adulto , Idoso , Anticorpos Antivirais/isolamento & purificação , COVID-19 , Cromatografia de Afinidade , Infecções por Coronavirus/imunologia , Feminino , Humanos , Imunoglobulina G/isolamento & purificação , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/imunologia , SARS-CoV-2 , Inquéritos e Questionários
13.
Bull Exp Biol Med ; 166(5): 622-625, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30903500

RESUMO

Over many years, tick-borne infections remain one of the most serious threats to human health worldwide. The immune response to these infections in a human after confirmed bite by an infected carrier at the early stages of infection in the absence of clinical symptoms can be the first indicator of the presence of the infectious agent in the body. During viral infection, the concentration of IL-1α, IL-8, IL-10, IL-17A, and IFNγ increases; superoxide dismutase also increases, in contrast to bacterial infections. A slight decrease in the concentration is observed only for receptor antagonist IL-1Ra. During the infection caused by bacterial pathogens, very similar profiles of the innate human immune response are observed: activation of IL-1α, IL-8, and IFNα and suppression of superoxide dismutase, IL-1Ra, and IL-17A production. It has been demonstrated, that the immune response is triggered immediately after infection, and changes in the concentration of the main cytokines in the blood plasma can be detected as early as on days 2-5 after tick bite. These results can be useful in developing new methods of emergency diagnosis and prevention of tick-borne infections.


Assuntos
Citocinas/metabolismo , Doenças Transmitidas por Carrapatos/imunologia , Animais , Infecções Bacterianas/imunologia , Vírus da Encefalite Transmitidos por Carrapatos/imunologia , Vírus da Encefalite Transmitidos por Carrapatos/patogenicidade , Humanos , Interleucina-17/metabolismo , Interleucina-1alfa/metabolismo , Doenças Transmitidas por Carrapatos/metabolismo
14.
J Epidemiol ; 28(9): 382-387, 2018 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-29607886

RESUMO

BACKGROUND: Foodborne norovirus outbreak data in Japan from 2005-2006, involving virological surveillance of all symptomatic and asymptomatic individuals, were reanalyzed to estimate the asymptomatic ratio of norovirus infection along with the risk of infection and the probability of virus shedding. METHODS: Employing a statistical model that is considered to capture the data-generating process of the outbreak and virus surveillance, maximum likelihood estimation of the asymptomatic ratio was implemented. RESULTS: Assuming that all norovirus outbreaks (n = 55) were the result of random sampling from an identical distribution and ignoring genogroup and genotype specificities, the asymptomatic ratio was estimated at 32.1% (95% confidence interval [CI], 27.7-36.7). Although not significant, separate estimation of the asymptomatic ratio of the GII.4 genotype appeared to be greater than other genotypes and was estimated at 40.7% (95% CI, 32.8-49.0). CONCLUSION: The present study offered the first explicit empirical estimates of the asymptomatic ratio of norovirus infection in natural infection settings. The estimate of about 30% was consistent with those derived from volunteer challenge studies. Practical difficulty in controlling GII.4 outbreaks was supported by the data, considering that a large estimate of the asymptomatic ratio was obtained for the GII.4 genotype.


Assuntos
Doenças Assintomáticas/epidemiologia , Infecções por Caliciviridae/epidemiologia , Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Norovirus/isolamento & purificação , Técnicas de Laboratório Clínico/estatística & dados numéricos , Genótipo , Humanos , Japão/epidemiologia , Modelos Estatísticos , Norovirus/genética
15.
BMC Vet Res ; 14(1): 130, 2018 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-29661203

RESUMO

BACKGROUND: This study sought to evaluate the effect of sow vaccination against Porcine circovirus 2 (PCV2) on reproductive parameters during two consecutive reproductive cycles. The study was performed in a PCV2 subclinical infected breeding herd (PCV2 circulation but absence of major reproductive problems). Ninety-four pregnant sows were primo-immunized with a commercial PCV2 vaccine and ninety-seven were injected with phosphate-buffered saline at 6 and 3 weeks before the first studied farrowing, and then boosted at 2 weeks before the second one. Blood samples were taken throughout the study to assess PCV2 DNA load and antibodies. At farrowing, main reproductive parameters and piglet vitality index were registered. In addition, in those litters with more than three mummified or stillborn piglets, microscopic examination and PCV2 antigen detection in foetal myocardium was done. RESULTS: Vaccinated sows showed significantly higher antibody levels compared to the non-vaccinated counterparts. PCV2 DNA was only detected at farrowing in 2 (4.2%) non-vaccinated sows. Vaccinated sows had 1.3 more live-born piglets per litter at the second cycle than non-vaccinated counterparts. Piglets from vaccinated sows had significantly higher (+ 12.7%) vitality score than the ones born from non-vaccinated sows. No PCV2 compatible lesions neither PCV2 antigen were detected in the tested foetal hearts. CONCLUSIONS: The present study represents a first attempt to demonstrate that PCV2 sow vaccination may have a positive influence on prolificacy and vitality of the offspring in a subclinical infected breeding herd. However, since reproductive outcomes at farm level may be affected by a number of factors, further studies would be needed to confirm this association.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus , Reprodução/efeitos dos fármacos , Doenças dos Suínos/virologia , Vacinas Virais/efeitos adversos , Animais , Anticorpos Antivirais/sangue , Infecções Assintomáticas , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/patologia , Infecções por Circoviridae/virologia , DNA Viral/sangue , Feminino , Natimorto/veterinária , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/prevenção & controle , Carga Viral/efeitos dos fármacos , Vacinas Virais/farmacologia
16.
Trop Anim Health Prod ; 50(5): 1167-1170, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29388163

RESUMO

Foot-and-mouth disease (FMD) is a highly contagious and economically important, transboundary viral disease of cloven-hoofed animals. It is known that an asymptomatic, persistent FMD virus (FMDV) infection may occur subsequent to acute or subclinical FMDV infection in adult ruminants. However, virus persistence in young calves has not been studied. In the current investigation, FMDV infection parameters were examined for calves born to FMD-clinically recovered cows (CRC), asymptomatic cows from infected herds (ASC) and cows from with no history of FMD (NHF). The study was conducted in natural condition after FMD outbreaks in two dairy herds in India. No calves described herein had any clinical signs of FMD. Six out of 12 calves born to CRC had detectable FMDV RNA in oesophageal-pharyngeal fluid consistent with asymptomatic FMDV infection. Three of the 12 calves of CRC group had seroreactivity against FMDV non-structural proteins. One calf had detectable FMDV RNA at two consecutive samplings at 2 months apart. However, infectious FMDV was not isolated from any calf in the study. None of the calves in the ASC or NHF groups had any evidence of FMDV infection. Overall, these data are consistent with earlier report on calves having been infected in utero. Further investigation of FMDV persistence in calves under controlled conditions may lead to greater understanding of the viral pathogenesis.


Assuntos
Doenças dos Bovinos/transmissão , Febre Aftosa/transmissão , Transmissão Vertical de Doenças Infecciosas/veterinária , Animais , Bovinos , Surtos de Doenças/veterinária , Feminino , Vírus da Febre Aftosa/isolamento & purificação , Índia
18.
Clin Exp Immunol ; 190(2): 226-234, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28708268

RESUMO

Many patients with primary immunodeficiency (PID) who have antibody deficiency develop progressive lung disease due to underlying subclinical infection and inflammation. To understand how these patients are monitored we conducted a retrospective survey based on patient records of 13 PID centres across Europe, regarding the care of 1061 adult and 178 paediatric patients with PID on immunoglobulin (Ig) G replacement. The most common diagnosis was common variable immunodeficiency in adults (75%) and hypogammaglobulinaemia in children (39%). The frequency of clinic visits varied both within and between centres: every 1-12 months for adult patients and every 3-6 months for paediatric patients. Patients diagnosed with lung diseases were more likely to receive pharmaceutical therapies and received a wider range of therapies than patients without lung disease. Variation existed between centres in the frequency with which some clinical and laboratory monitoring tests are performed, including exercise tests, laboratory testing for IgG subclass levels and specific antibodies, and lung function tests such as spirometry. Some tests were carried out more frequently in adults than in children, probably due to difficulties conducting these tests in younger children. The percentage of patients seen regularly by a chest physician, or who had microbiology tests performed following chest and sinus exacerbations, also varied widely between centres. Our survey revealed a great deal of variation across Europe in how frequently patients with PID visit the clinic and how frequently some monitoring tests are carried out. These results highlight the urgent need for consensus guidelines on how to monitor lung complications in PID patients.


Assuntos
Síndromes de Imunodeficiência/fisiopatologia , Pneumopatias/complicações , Sistema Respiratório/fisiopatologia , Adulto , Agamaglobulinemia/fisiopatologia , Assistência Ambulatorial , Infecções Assintomáticas/epidemiologia , Criança , Imunodeficiência de Variável Comum/fisiopatologia , Europa (Continente) , Feminino , Humanos , Imunização Passiva , Imunoglobulina G/uso terapêutico , Imunoglobulinas/uso terapêutico , Síndromes de Imunodeficiência/complicações , Síndromes de Imunodeficiência/imunologia , Síndromes de Imunodeficiência/terapia , Pneumopatias/diagnóstico , Pneumopatias/imunologia , Pneumopatias/prevenção & controle , Masculino , Prontuários Médicos , Guias de Prática Clínica como Assunto , Estudos Retrospectivos , Espirometria
19.
J Infect Dis ; 214(12): 1929-1936, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27923953

RESUMO

BACKGROUND: In Indonesia, highly pathogenic avian influenza A(H5N1) virus has become endemic in poultry and has caused sporadic deadly infections in human. Since 2012, we have conducted fixed-point surveillance of avian influenza viruses at a live-poultry market in East Java, Indonesia. In this study, we examined the seroprevalence of avian influenza A(H5N1) virus infection among market workers. METHODS: Sera were collected from 101 workers in early 2014 and examined for antibody activity against avian A(H5N1) Eurasian lineage virus by a hemagglutination-inhibition (HI) assay. RESULTS: By the HI assay, 84% of the sera tested positive for antibody activity against the avian virus. Further analysis revealed that the average HI titer in 2014 was 2.9-fold higher than in 2012 and that seroconversion occurred in 44% of paired sera (11 of 25) between 2012 and 2014. A medical history survey was performed in 2016; responses to questionnaires indicated that none of workers had had severe acute respiratory illness during 2013. CONCLUSIONS: This study provides evidence of a high prevalence of avian A(H5N1) virus infection in 2013 among workers at a live-poultry market. However, because no instances of hospitalizations were reported, we can conclude the virus did not manifest any clinical symptoms in workers.


Assuntos
Criação de Animais Domésticos , Anticorpos Antivirais/sangue , Infecções Assintomáticas/epidemiologia , Virus da Influenza A Subtipo H5N1/imunologia , Influenza Humana/epidemiologia , Exposição Ocupacional , Animais , Testes de Inibição da Hemaglutinação , Humanos , Indonésia/epidemiologia , Aves Domésticas , Estudos Soroepidemiológicos
20.
Cytokine ; 83: 176-181, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27155064

RESUMO

Peromyscus yucatanicus, the main reservoir of Leishmania (Leishmania) mexicana in the Yucatan peninsula of Mexico, reproduces clinical and histological pictures of LCL in human as well as subclinical infection. Thus, we used this rodent as a novel experimental model. In this work, we analyzed cytokine mRNA expression in P. yucatanicus infected with L. (L.) mexicana. Animals were inoculated with either 2.5×10(6) or 1×10(2) promastigotes and cytokine expressions were analyzed by real-time RT-PCR in skin at 4 and 12weeks post-infection (wpi). Independently of the parasite inoculum none of the infected rodents had clinical signs of LCL at 4wpi and all expressed high IFN-γ mRNA. All P. yucatanicus inoculated with 2.5×10(6) promastigotes developed signs of LCL at 12wpi while the mice inoculated with 1×10(2) remained subclinical. At that time, both IFN-γ and IL-10 were expressed in P. yucatanicus with clinical and subclinical infections. Expressions of TNF-α and IL-4 were significantly higher in clinical animals (2.5×10(6)) compared with subclinical ones (1×10(2)). High TGF-ß expression was observed in P. yucatanicus with clinical signs when compared with healthy animals. Results suggested that the clinical course of L. (L.) mexicana infection in P. yucatanicus was associated with a specific local pattern of cytokine production at 12wpi.


Assuntos
Citocinas/biossíntese , Regulação da Expressão Gênica , Leishmania mexicana/metabolismo , Leishmaniose Cutânea/metabolismo , Peromyscus/metabolismo , Animais , Peromyscus/parasitologia , RNA Mensageiro/biossíntese
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