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1.
J Gen Virol ; 104(11)2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37910158

RESUMO

Enteroviruses primarily affect young children with a varying severity of disease. Recent outbreaks of severe respiratory and neurological disease due to EV-D68 and EV-A71, as well as atypical hand-foot-and-mouth-disease due to CVA6, have brought to light the potency of enteroviruses to emerge as severe human pathogens. Enterovirus D111 (EV-D111) is an enteric pathogen initially detected in Central Africa in human and wildlife samples and was recently detected in environmental samples. The natural history and epidemiology of EV-D111 are poorly studied. Here, the presence of serum neutralizing antibodies to EV-D111 was estimated in human and wildlife samples from five countries. We report high prevalence of neutralizing antibodies measured against EV-D111 in human populations (range, 55-83 %), a proxy for previous infection, which indicates active virus circulation in absence of detection in clinical cases and a high number of undiagnosed infections. Notably, seroprevalence in samples from the UK varied by age and was higher in children and older adults (1-5 and >60 years old), but lower in ages 11-60. EV-D111 seroprevalence in apes and Old World monkeys was 50 % (33-66 %), which also suggests prior exposure and supports existing knowledge of enterovirus circulation in wild and captive apes and Old World monkeys. Generally, reported cases of infection likely underestimate the prevalence of infection particularly when the knowledge of community transmission is limited. Continued serologic surveillance and detection of EV-D111 in clinical and environmental samples will allow for a more robust assessment of EV-D111 epidemiology.


Assuntos
Infecções por Enterovirus , Enterovirus , Hominidae , Animais , Humanos , Pré-Escolar , Idoso , Estudos Transversais , Prevalência , Estudos Soroepidemiológicos , Primatas , Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/veterinária , Cercopithecidae , Animais Selvagens , Anticorpos Neutralizantes , Antígenos Virais
2.
Lancet ; 400(10362): 1531-1538, 2022 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-36243024

RESUMO

BACKGROUND: The international spread of poliovirus exposes all countries to the risk of outbreaks and is designated a Public Health Emergency of International Concern by WHO. This risk can be exacerbated in countries using inactivated polio vaccine, which offers excellent protection against paralysis but is less effective than oral vaccine against poliovirus shedding, potentially allowing circulation without detection of paralytic cases for long periods of time. Our study investigated the molecular properties of type 2 poliovirus isolates found in sewage with an aim to detect virus transmission in the community. METHODS: We performed environmental surveillance in London, UK, testing sewage samples using WHO recommended methods that include concentration, virus isolation in cell culture, and molecular characterisation. We additionally implemented direct molecular detection and determined whole-genome sequences of every isolate using novel nanopore protocols. FINDINGS: 118 genetically linked poliovirus isolates related to the serotype 2 Sabin vaccine strain were detected in 21 of 52 sequential sewage samples collected in London between Feb 8 and July 4, 2022. Expansion of environmental surveillance sites in London helped localise transmission to several boroughs in north and east London. All isolates have lost two key attenuating mutations, are recombinants with a species C enterovirus, and an increasing proportion (20 of 118) meet the criterion for a vaccine-derived poliovirus, having six to ten nucleotide changes in the gene coding for VP1 capsid protein. INTERPRETATION: Environmental surveillance allowed early detection of poliovirus importation and circulation in London, permitting a rapid public health response, including enhanced surveillance and an inactivated polio vaccine campaign among children aged 1-9 years. Whole-genome sequences generated through nanopore sequencing established linkage of isolates and confirmed transmission of a unique recombinant poliovirus lineage that has now been detected in Israel and the USA. FUNDING: Medicines and Healthcare products Regulatory Agency, UK Health Security Agency, Bill & Melinda Gates Foundation, and National Institute for Health Research Medical Research Council.


Assuntos
Poliomielite , Poliovirus , Criança , Humanos , Poliovirus/genética , Esgotos , Poliomielite/epidemiologia , Poliomielite/prevenção & controle , Londres/epidemiologia , Vacina Antipólio Oral , Vacina Antipólio de Vírus Inativado , Monitoramento Ambiental/métodos
3.
MMWR Morb Mortal Wkly Rep ; 71(24): 786-790, 2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35709073

RESUMO

The emergence and international spread of neurovirulent circulating vaccine-derived polioviruses (cVDPVs) across multiple countries in Africa and Asia in recent years pose a major challenge to the goal of eradicating all forms of polioviruses. Approximately 90% of all cVDPV outbreaks are caused by the type 2 strain of the Sabin vaccine, an oral live, attenuated vaccine; cVDPV outbreaks typically occur in areas of persistently low immunization coverage (1). A novel type 2 oral poliovirus vaccine (nOPV2), produced by genetic modification of the type 2 Sabin vaccine virus genome (2), was developed and evaluated through phase I and phase II clinical trials during 2017-2019. nOPV2 was demonstrated to be safe and well-tolerated, have noninferior immunogenicity, and have superior genetic stability compared with Sabin monovalent type 2 (as measured by preservation of the primary attenuation site [domain V in the 5' noncoding region] and significantly lower neurovirulence of fecally shed vaccine virus in transgenic mice) (3-5). These findings indicate that nOPV2 could be an important tool in reducing the risk for generating vaccine-derived polioviruses (VDPVs) and the risk for vaccine-associated paralytic poliomyelitis cases. Based on the favorable preclinical and clinical data, and the public health emergency of international concern generated by ongoing endemic wild poliovirus transmission and cVDPV type 2 outbreaks, the World Health Organization authorized nOPV2 for use under the Emergency Use Listing (EUL) pathway in November 2020, allowing for its first use for outbreak response in March 2021 (6). As required by the EUL process, among other EUL obligations, an extensive plan was developed and deployed for obtaining and monitoring nOPV2 isolates detected during acute flaccid paralysis (AFP) surveillance, environmental surveillance, adverse events after immunization surveillance, and targeted surveillance for adverse events of special interest (i.e., prespecified events that have the potential to be causally associated with the vaccine product), during outbreak response, as well as through planned field studies. Under this monitoring framework, data generated from whole-genome sequencing of nOPV2 isolates, alongside other virologic data for isolates from AFP and environmental surveillance systems, are reviewed by the genetic characterization subgroup of an nOPV working group of the Global Polio Eradication Initiative. Global nOPV2 genomic surveillance during March-October 2021 confirmed genetic stability of the primary attenuating site. Sequence data generated through this unprecedented global effort confirm the genetic stability of nOPV2 relative to Sabin 2 and suggest that nOPV2 will be an important tool in the eradication of poliomyelitis. nOPV2 surveillance should continue for the duration of the EUL.


Assuntos
Poliomielite , Vacina Antipólio Oral , Poliovirus , Animais , Viroses do Sistema Nervoso Central/prevenção & controle , Surtos de Doenças/prevenção & controle , Humanos , Camundongos , Mielite/prevenção & controle , Doenças Neuromusculares/prevenção & controle , Poliomielite/epidemiologia , Poliomielite/etiologia , Poliomielite/prevenção & controle , Poliovirus/genética , Vacina Antipólio Oral/efeitos adversos , Vacina Antipólio Oral/genética , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/genética
4.
J Clin Microbiol ; 58(9)2020 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-32611795

RESUMO

Global poliovirus surveillance involves virus isolation from stool and environmental samples, intratypic differential (ITD) by PCR, and sequencing of the VP1 region to distinguish vaccine (Sabin), vaccine-derived, and wild-type polioviruses and to ensure an appropriate response. This cell culture algorithm takes 2 to 3 weeks on average between sample receipt and sequencing. Direct detection of viral RNA using PCR allows faster detection but has traditionally faced challenges related to poor sensitivity and difficulties in sequencing common samples containing poliovirus and enterovirus mixtures. We present a nested PCR and nanopore sequencing protocol that allows rapid (<3 days) and sensitive direct detection and sequencing of polioviruses in stool and environmental samples. We developed barcoded primers and a real-time analysis platform that generate accurate VP1 consensus sequences from multiplexed samples. The sensitivity and specificity of our protocol compared with those of cell culture were 90.9% (95% confidence interval, 75.7% to 98.1%) and 99.2% (95.5% to 100.0%) for wild-type 1 poliovirus, 92.5% (79.6% to 98.4%) and 98.7% (95.4% to 99.8%) for vaccine and vaccine-derived serotype 2 poliovirus, and 88.3% (81.2% to 93.5%) and 93.2% (88.6% to 96.3%) for Sabin 1 and 3 poliovirus alone or in mixtures when tested on 155 stool samples in Pakistan. Variant analysis of sequencing reads also allowed the identification of polioviruses and enteroviruses in artificial mixtures and was able to distinguish complex mixtures of polioviruses in environmental samples. The median identity of consensus nanopore sequences with Sanger or Illumina sequences from the same samples was >99.9%. This novel method shows promise as a faster and safer alternative to cell culture for the detection and real-time sequencing of polioviruses in stool and environmental samples.


Assuntos
Sequenciamento por Nanoporos , Poliomielite , Poliovirus , Monitoramento Ambiental , Fezes , Humanos , Poliomielite/diagnóstico , Poliovirus/genética , Vacina Antipólio Oral
5.
J Infect Dis ; 217(8): 1222-1230, 2018 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-29309594

RESUMO

Background: Environmental surveillance (ES) is a sensitive method for detecting human enterovirus (HEV) circulation, and it is used worldwide to support global polio eradication. We describe a novel ES approach using next-generation sequencing (NGS) to identify HEVs in sewage samples collected in London, United Kingdom, from June 2016 to May 2017. Methods: Two different methods were used to process raw sewage specimens: a 2-phase aqueous separation system and size exclusion by filtration and centrifugation. HEVs were isolated using cell cultures and analyzed using NGS. Results: Type 1 and 3 vaccine-like poliovirus (PV) strains were detected in samples collected from September 2016 through January 2017. NGS analysis allowed us to rapidly obtain whole-genome sequences of PV and non-PV HEV strains. As many as 6 virus strains from different HEV serotypes were identified in a single cell culture flask. PV isolates contained only a small number of mutations from vaccine strains commonly seen in early isolates from vaccinees. Conclusions: Our ES setup has high sensitivity for polio and non-PV HEV detection, generating nearly whole-genome sequence information. Such ES systems provide critical information to assist the polio eradication endgame and contribute to the improvement of our understanding of HEV circulation patterns in humans.


Assuntos
Vacinas contra Poliovirus , Poliovirus/classificação , Poliovirus/genética , Esgotos/virologia , Monitoramento Ambiental , Genoma Viral , Humanos , Técnicas de Amplificação de Ácido Nucleico , Poliovirus/isolamento & purificação , Reino Unido
6.
Emerg Infect Dis ; 24(1): 65-74, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29260690

RESUMO

During the 2014-2015 outbreak of Ebola virus disease in Guinea, 13 type 2 circulating vaccine-derived polioviruses (cVDPVs) were isolated from 6 polio patients and 7 healthy contacts. To clarify the genetic properties of cVDPVs and their emergence, we combined epidemiologic and virologic data for polio cases in Guinea. Deviation of public health resources to the Ebola outbreak disrupted polio vaccination programs and surveillance activities, which fueled the spread of neurovirulent VDPVs in an area of low vaccination coverage and immunity. Genetic properties of cVDPVs were consistent with their capacity to cause paralytic disease in humans and capacity for sustained person-to-person transmission. Circulation ceased when coverage of oral polio vaccine increased. A polio outbreak in the context of the Ebola virus disease outbreak highlights the need to consider risks for polio emergence and spread during complex emergencies and urges awareness of the challenges in polio surveillance, vaccination, and diagnosis.


Assuntos
Doença pelo Vírus Ebola/complicações , Poliomielite/epidemiologia , Poliomielite/virologia , Poliovirus/genética , Substituição de Aminoácidos , Sequência de Bases , Surtos de Doenças , Fezes/virologia , Genoma Viral , Saúde Global , Guiné/epidemiologia , Doença pelo Vírus Ebola/epidemiologia , Humanos , Hospedeiro Imunocomprometido , Filogenia , Vacina Antipólio Oral , Saúde Pública , Vacinação , Proteínas Virais/genética , Proteínas Virais/metabolismo
7.
Emerg Infect Dis ; 24(4): 754-757, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29553325

RESUMO

We analyzed whole-genome sequences of 8 enterovirus A71 isolates (EV-A71). We confirm the circulation of genogroup C and the new genogroup E in West Africa. Our analysis demonstrates wide geographic circulation and describes genetic exchanges between EV-A71 and autochthonous EV-A that might contribute to the emergence of pathogenic lineages.


Assuntos
Enterovirus Humano A/classificação , Enterovirus Humano A/genética , Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/virologia , Variação Genética , Genoma Viral , Genótipo , Humanos , Filogenia , Recombinação Genética
8.
Indian J Med Res ; 146(4): 541-544, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-29434070

RESUMO

Culture-negative bacteraemia has been an enigmatic entity with respect to its aetiological agents. In an attempt to actively identify those positive blood cultures that escape isolation and detection on routine workflow, an additional step of MALDI-TOF MS (matrix-assisted laser desorption ionization-time of flight mass spectrometry) based detection was carried out directly from the flagged blood culture bottles. Blood samples from 200 blood culture bottles that beeped positive with automated (BACTEC) system and showed no growth of organism on routine culture media, were subjected to analysis by MALDI-TOF MS. Forty seven of the 200 (23.5%) bacterial aetiology could be established by bottle-based method. Based on these results, growth on culture medium could be achieved for the isolates by providing special growth conditions to the fastidious organisms. Direct identification by MALDI-TOF MS from BACTEC-positive bottles provided an opportunity to isolate those fastidious organisms that failed to grow on routine culture medium by providing them with necessary alterations in growth environment.


Assuntos
Bacteriemia/diagnóstico , Bactérias/isolamento & purificação , Técnicas Bacteriológicas , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Bacteriemia/microbiologia , Bactérias/patogenicidade , Hemocultura , Meios de Cultura/análise , Humanos
9.
Liver Int ; 35(3): 826-33, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24750588

RESUMO

BACKGROUND & AIMS: Every year globally WHO reports 20 million Hepatitis E virus (HEV) infections. The disease occurs as sporadic cases or focused outbreaks and has potentials to cause massive epidemics. The reservoir of HEV during inter-epidemic period is not well characterized. The sporadic cases usually lack history of contact with clinically overt HEV patients. In the present context we evaluated the occurrence of subclinical HEV as a possible reservoir in endemic region. METHODS: Blood samples were collected from 67 apparently healthy individuals and 10 acute viral hepatitis (AVH) patients during two HEV outbreaks in North India. The serum samples were tested for anti-HEV IgM, IgG, HEV-IgG avidity index, HEV viral load and conventional-PCR followed by sequencing and phylogenetic analysis. RESULTS: A total of 14 (20.89%) apparently healthy individuals showed the presence of anti-HEV IgM and IgG. Of 14 based on HEV-IgG avidity index, 9 (64.28%) had secondary-exposure, 4 (28.57%) had primary exposure, while one patient had intermediate avidity. Subclinical subjects with primary exposure had significantly higher anti-HEV IgM index as compared to secondary-exposure (P = 0.0028). Viral load in clinically jaundiced patients was significantly higher as compared to subclinical subjects (P < 0.0001). Phylogenetic analysis showed HEV sequences retrieved from subclinical individuals clustered along with AVH patients, suggesting matched source. The significantly low viral load in subclinical subjects hints towards the dose dependency for progression of clinical manifestation. CONCLUSION: We document subclinical HEV with low level viremia occurs during outbreak settings and goes un-noticed, which helps maintaining the virus in nature possibly leading to its endemicity.


Assuntos
Anticorpos Anti-Hepatite/sangue , Vírus da Hepatite E/isolamento & purificação , Hepatite E/epidemiologia , Imunoglobulina M/sangue , RNA Viral/sangue , Adolescente , Adulto , Surtos de Doenças , Feminino , Hepatite E/diagnóstico , Vírus da Hepatite E/genética , Humanos , Imunoglobulina G/sangue , Índia/epidemiologia , Masculino , Filogenia , Testes Sorológicos , Carga Viral , Adulto Jovem
10.
Indian J Med Res ; 141(2): 213-20, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25900957

RESUMO

BACKGROUND & OBJECTIVES: Hepatitis A virus usually causes acute viral hepatitis (AVH) in the paediatric age group with a recent shift in age distribution and disease manifestations like acute liver failure (ALF). This has been attributed to mutations in 5'non-translated region (5'NTR) which affects the viral multiplication. The present study was aimed to carry out the molecular detection and phylogenetic analysis of hepatitis A virus strains circulating in north western India. METHODS: Serum samples from in patients and those attending out patient department of Pediatric Gastroenterology in a tertiary care hospital in north India during 2007-2011 with clinically suspected AVH were tested for anti-hepatitis A virus (HAV) IgM antibodies. Acute phase serum samples were subjected to nested PCR targeting the 5'NTR region followed by sequencing of the representative strains. RESULTS: A total of 1334 samples were tested, 290 (21.7%) were positive for anti-HAV IgM antibody. Of these, 78 serum samples (< 7 days old) were subjected to PCR and 47.4% (37/78) samples showed the presence of HAV RNA. Children < 15 yr of age accounted for majority (94%) of cases with highest seropositivity during rainy season. Sequencing of 15 representative strains was carried out and the circulating genotype was found to be III A. The nucleotide sequences showed high homology among the strains with a variation ranging from 0.1-1 per cent over the years. An important substitution of G to A at 324 position was shown by both AVH and ALF strains. The cumulative substitution in AVH strains Vs ALF strains as compared to GBM, Indian and prototype strain in the 200-500 region of 5' NTR was comparable. INTERPRETATION & CONCLUSION: Our results showed hepatitis A still a disease of children with III A as a circulating genotype in this region. The mutations at 5'NTR region warrant further analysis as these affect the structure of internal ribosomal entry site which is important for viral replication.


Assuntos
Vírus da Hepatite A/genética , Hepatite A/sangue , Hepatite A/genética , Imunoglobulina M/sangue , Regiões 5' não Traduzidas/genética , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Criança , Pré-Escolar , Feminino , Genótipo , Hepatite A/imunologia , Hepatite A/virologia , Vírus da Hepatite A/imunologia , Vírus da Hepatite A/patogenicidade , Humanos , Imunoglobulina M/genética , Imunoglobulina M/imunologia , Índia , Masculino , Mutação , Filogenia , Atenção Terciária à Saúde
11.
J Med Virol ; 86(4): 713-9, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24375126

RESUMO

Hepatitis E virus (HEV) is the causative agent of hepatitis E. It can be asymptomatic, associated with acute self-limiting hepatitis or acute liver failure. The conventional diagnosis of HEV infection relies on anti-HEV IgM serology. The collection of blood samples by venepunture for laboratory confirmation is often difficult during an outbreak. Thus, testing the specimens of dried blood spots (DBS) on filter papers can prove to be a feasible alternative. The present study aimed to evaluate the applicability of anti-HEV IgM detection from DBS samples and the stability of anti-HEV IgM detection at varied time interval, at various storage temperatures. Paired blood and DBS sample were collected from 44 jaundiced patients and eight healthy controls during HEV outbreaks. The DBS were tested for anti-HEV IgM by available ELISA kit with in-house modifications. Three cut offs were determined, that is, the CO1: kit cut-off, CO2: mean of negative controls above 3SD and CO3: area under Receiver operating Curve. The sensitivity of anti-HEV IgM detection ranged from 86-91%. The maximum sensitivity (91%) and specificity (100%) was obtained using CO3. Maximum stability of anti-HEV IgM antibodies (100%) was observed till 65 days at 4°C. Storage at 37°C significantly reduced anti-HEV IgM positivity, wherein 42.85% sample became negative by 45 days. DBS showed good sensitivity and specificity for detecting anti-HEV IgM and can be considered an alternate to serum sample. Moreover, anti-HEV IgM was stable at 4°C, which makes DBS a preferred method for storage and transportation of the sample to reference laboratory.


Assuntos
Teste em Amostras de Sangue Seco/métodos , Hepatite E/sangue , Hepatite E/diagnóstico , Icterícia/sangue , Biomarcadores/sangue , Surtos de Doenças , Anticorpos Anti-Hepatite/sangue , Hepatite E/virologia , Vírus da Hepatite E/imunologia , Humanos , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Icterícia/virologia , RNA Viral/sangue
12.
Virus Evol ; 10(1): veae023, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38544854

RESUMO

Widespread surveillance, rapid detection, and appropriate intervention will be critical for successful eradication of poliovirus. Using deployable next-generation sequencing (NGS) approaches, such as Oxford Nanopore Technologies' MinION, the time from sample to result can be significantly reduced compared to cell culture and Sanger sequencing. We developed piranha (poliovirus investigation resource automating nanopore haplotype analysis), a 'sequencing reads-to-report' solution to aid routine poliovirus testing of both stool and environmental samples and alleviate the bioinformatic bottleneck that often exists for laboratories adopting novel NGS approaches. Piranha can be used for efficient intratypic differentiation of poliovirus serotypes, for classification of Sabin-like polioviruses, and for detection of wild-type and vaccine-derived polioviruses. It produces interactive, distributable reports, as well as summary comma-separated values files and consensus poliovirus FASTA sequences. Piranha optionally provides phylogenetic analysis, with the ability to incorporate a local database, processing from raw sequencing reads to an interactive, annotated phylogeny in a single step. The reports describe each nanopore sequencing run with interpretable plots, enabling researchers to easily detect the presence of poliovirus in samples and quickly disseminate their results. Poliovirus eradication efforts are hindered by the lack of real-time detection and reporting, and piranha can be used to complement direct detection sequencing approaches.

13.
J Med Virol ; 85(5): 823-7, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23408566

RESUMO

Hepatitis E virus (HEV) is implicated in many outbreaks of viral hepatitis in the Indian subcontinent. The conventional diagnosis of such outbreaks rests on the detection of anti-HEV IgM antibodies. However, IgM antibodies develop after 4-5 days of infection. An early-diagnostic marker is imperative for timely diagnosis of the outbreak and also initiation of control measures. This study aimed to determine the use of hepatitis E virus antigen detection as an early diagnostic marker in an outbreak in comparison to anti-HEV IgM and RT-PCR analyses. Forty samples were collected during a suspected outbreak of viral hepatitis due to HEV. A total of 36 samples were positive for one or more HEV markers. The positivity for anti-HEV IgM, HEV antigen, and RT-PCR was 91.6%, 69.4%, and 47.2% respectively. RT-PCR and HEV antigen detection gave the highest positive results (100%) in the first 3 days of illness. Positive HEV PCR declined to 54% by Days 4-7, whereas HEV antigen and IgM detection were 88% and 100%, respectively. Sequencing of representative HEV samples indicated that the strains responsible for this outbreak belonged to genotype I, subtype 1a. HEV antigen was found to be an early diagnostic marker of acute infection. HEV antigen was detected in three additional cases in the early phase (1-3 days), and they had no detectable anti-HEV IgM antibodies. These three samples were also positive for HEV RNA. After Day 7, anti-HEV IgM was the main diagnostic indicator of infection.


Assuntos
Antígenos Virais/sangue , Biomarcadores/sangue , Surtos de Doenças , Vírus da Hepatite E/isolamento & purificação , Hepatite E/diagnóstico , Hepatite E/epidemiologia , Adulto , Feminino , Anticorpos Anti-Hepatite/sangue , Humanos , Imunoglobulina M/sangue , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , RNA Viral/sangue , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Análise de Sequência de DNA , Fatores de Tempo , Adulto Jovem
14.
Liver Int ; 33(9): 1341-8, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23682703

RESUMO

BACKGROUND: Viral hepatitis E clinically ranges between acute self-limiting hepatitis (AVH) and acute liver failure (ALF). The varied clinical course of the disease possibly thought to be immune-mediated. High-mobility group box 1 (HMGB1) is a non-histone chromosomal nuclear protein with recently discovered pro-inflammatory and immunomodulatory action. Its presence in abundance within hepatocytes is thought provoking in patients with hepatitis. AIM: The present study was designed to elucidate the role of circulating HMGB1 and its gene expression in patients with viral hepatitis E. METHODS: Blood samples were obtained from AVH (n = 38), ALF (n = 34) and healthy controls (HC, n = 30). The HMGB1 levels were estimated in serum by quantitative-micro-ELISA. Gene expression levels were studied in the patient's PBMCs by real-time PCR. Lymphocyte proliferation was estimated by colorimetric-MTT assay. RESULTS: Mean circulating HMGB1 levels in HC, AVH and ALF patients were found to be 12.04 ± 2.23, 112.6 ± 13.33 and 225.3 ± 15.04 ng/ml respectively. The levels were significantly higher in ALF than AVH and HC (P < 0.0001). Moreover, 88.2% of ALF patients with >250 ng/ml of circulating HMGB1 had a fatal outcome. The gene expression of HMGB1 in the PBMCs of ALF and AVH patients were comparable. A positive correlation was observed between HMGB1 level and INR. A significantly low lymphocyte proliferation was observed in ALF patients (P = 0.008). CONCLUSION: Massive necrosis of hepatocytes in ALF patients might predispose to excessive accumulation of extracellular HMGB1 leading to suppression of T-cell proliferation. Therefore, it is proposed that excessive circulating HMGB1 might play an important role in immunosuppression and fulminant course of the disease following HEV infection.


Assuntos
Biomarcadores/sangue , Regulação da Expressão Gênica/imunologia , Proteína HMGB1/sangue , Hepatite E/complicações , Falência Hepática Aguda/diagnóstico , Falência Hepática Aguda/etiologia , Adulto , Colorimetria , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Leucócitos Mononucleares/imunologia , Falência Hepática Aguda/sangue , Masculino , Reação em Cadeia da Polimerase em Tempo Real , Estatísticas não Paramétricas , Sais de Tetrazólio , Tiazóis
15.
Front Immunol ; 14: 1135834, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36936936

RESUMO

The global polio eradication campaign has had remarkable success in reducing wild-type poliovirus infection, largely built upon the live attenuated Sabin oral poliovirus vaccine. Whilst rare, vaccine poliovirus strains may cause infection and subsequently revert to a neurovirulent type, termed vaccine-derived poliovirus (VDPV). Persistent, vaccine derived infection may occur in an immunocompromised host (iVDPV), where it is a recognised complication following receipt of the Sabin vaccine. This has significant implications for the global polio eradication campaign and there is currently no agreed global strategy to manage such patients.Here we describe a case of a 50-year-old man with common variable immune deficiency, persistently infected with a neurovirulent vaccine-derived type 2 poliovirus following vaccination in childhood. iVDPV infection had proven resistant to multiple prior attempts at treatment with human breast milk, ribavirin and oral administration of a normal human pooled immunoglobulin product. His iVDPV infection subsequently resolved after 12 days treatment with remdesivir, an adenosine analogue prodrug that is an inhibitor of viral RNA-dependent RNA polymerase, administered as treatment for a prolonged, moderate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. iVDPV from the patient, isolated prior to treatment, was subsequently demonstrated to be sensitive to remdesivir in vitro. Based on the observations made in this case, and the mechanistic rationale for use with iVDPV, there is strong justification for further clinical studies of remdesivir treatment as a potentially curative intervention in patients with iVDPV infection.


Assuntos
COVID-19 , Síndromes de Imunodeficiência , Poliomielite , Vacina Antipólio Oral , Poliovirus , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , COVID-19/complicações , Tratamento Farmacológico da COVID-19 , Poliomielite/tratamento farmacológico , Poliomielite/etiologia , Poliomielite/prevenção & controle , Vacina Antipólio Oral/efeitos adversos , SARS-CoV-2
16.
Microbiol Spectr ; : e0425222, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36939356

RESUMO

Direct detection by PCR of poliovirus RNA in stool samples provides a rapid diagnostic and surveillance tool that can replace virus isolation by cell culture in global polio surveillance. The sensitivity of direct detection methods is likely to depend on the choice of RNA extraction method and sample volume. We report a comparative analysis of 11 nucleic acid extraction methods (7 manual and 4 semiautomated) for poliovirus molecular detection using stool samples (n = 59) that had been previously identified as poliovirus positive by cell culture. To assess the effect of RNA recovery methods, extracted RNA using each of the 11 methods was tested with a poliovirus-specific reverse transcription-quantitative PCR (RT-qPCR), a pan-poliovirus RT-PCR (near-whole-genome amplification), a pan-enterovirus RT-PCR (entire capsid region), and a nested VP1 PCR that is the basis of a direct detection method based on nanopore sequencing. We also assessed extracted RNA integrity and quantity. The overall effect of extraction method on poliovirus PCR amplification assays tested in this study was found to be statistically significant (P < 0.001), thus indicating that the choice of RNA extraction method is an important component that needs to be carefully considered for any diagnostic based on nucleic acid amplification. Performance of the methods was generally consistent across the different assays used. Of the 11 extraction methods tested, the MagMAX viral RNA isolation kit used manually or automatically was found to be the preferable method for poliovirus molecular direct detection considering performance, cost, and processing time. IMPORTANCE Poliovirus, the causative agent of poliomyelitis, is a target of global eradication led by the World Health Organization since 1988. Direct molecular detection and genomic sequencing without virus propagation in cell culture is arguably a critical tool in the final stages of polio eradication. Efficient recovery of good-quality viral RNA from stool samples is a prerequisite for direct detection by nucleic acid amplification. We tested 11 nucleic acid extraction methods to identify those facilitating sensitive, fast, simple, and cost-effective extraction, with flexibility for manual and automated protocols considered. Several different PCR assays were used to compare the recovered viral RNA to test suitability for poliovirus direct molecular detection. Our findings highlight the importance of choosing a suitable RNA extraction protocol and provide useful information to diagnostic laboratories and researchers facing the choice of RNA extraction method for direct molecular virus detection from stool.

17.
Viruses ; 14(1)2022 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-35062346

RESUMO

Infection with enterovirus D68 (EV-D68) has been linked with severe neurological disease such as acute flaccid myelitis (AFM) in recent years. However, active surveillance for EV-D68 is lacking, which makes full assessment of this association difficult. Although a high number of EV-D68 infections were expected in 2020 based on the EV-D68's known biannual circulation patterns, no apparent increase in EV-D68 detections or AFM cases was observed during 2020. We describe an upsurge of EV-D68 detections in wastewater samples from the United Kingdom between July and November 2021 mirroring the recently reported rise in EV-D68 detections in clinical samples from various European countries. We provide the first publicly available 2021 EV-D68 sequences showing co-circulation of EV-D68 strains from genetic clade D and sub-clade B3 as in previous years. Our results show the value of environmental surveillance (ES) for the early detection of circulating and clinically relevant human viruses. The use of a next-generation sequencing (NGS) approach helped us to estimate the prevalence of EV-D68 viruses among EV strains from other EV serotypes and to detect EV-D68 minor variants. The utility of ES at reducing gaps in virus surveillance for EV-D68 and the possible impact of nonpharmaceutical interventions introduced to control the COVID-19 pandemic on EV-D68 transmission dynamics are discussed.


Assuntos
Enterovirus Humano D/isolamento & purificação , Águas Residuárias/virologia , COVID-19/epidemiologia , COVID-19/prevenção & controle , Proteínas do Capsídeo/genética , Enterovirus Humano D/classificação , Enterovirus Humano D/genética , Humanos , Filogenia , RNA Viral/genética , SARS-CoV-2 , Análise de Sequência de DNA , Reino Unido/epidemiologia , Vigilância Epidemiológica Baseada em Águas Residuárias , Microbiologia da Água
18.
Trop Anim Health Prod ; 43(1): 111-4, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20676764

RESUMO

The present study reports the first survey for the detection of antirabies antibodies in street and household dogs in India. We aimed to check the efficacy of control programs for the disease in the Union territory of Chandigarh. The serum samples were collected from 100 street and 50 household dogs and tested for the presence of antirabies antibodies by ELISA. As per WHO criteria, a titre of >0.5 IU/ml of antirabies antibody in serum samples was taken as the protective level. Protective antirabies antibody titre was found only in 1% of the street dogs and 16% of the pet dogs. The awareness among the pet dog owners about the antirabies vaccination schedule was low as 18% did not know the vaccination status of the dog and 66% had got the initial immunization done with only three doses and annual boosters were not given. A National Rabies Elimination Program needs to be launched as a collaborative venture by both medical and veterinary practitioners to curb this deadly disease. Also periodic surveys to test the status of antirabies IgG among dogs need to be carried out to ascertain the attainment of WHO protective levels.


Assuntos
Doenças do Cão/epidemiologia , Doenças do Cão/virologia , Lyssavirus/imunologia , Raiva/veterinária , Animais , Anticorpos Antivirais/sangue , Cidades , Cães , Ensaio de Imunoadsorção Enzimática , Índia/epidemiologia , Vacinação em Massa/métodos , Vacinação em Massa/veterinária , Prevalência , Raiva/epidemiologia
19.
Viruses ; 13(4)2021 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-33918088

RESUMO

There are increasing concerns of infections by enteroviruses (EVs) causing severe disease in humans. EV diagnostic laboratory methods show differences in sensitivity and specificity as well as the level of genetic information provided. We examined a detection method for EVs based on next generation sequencing (NGS) analysis of amplicons covering the entire capsid coding region directly synthesized from clinical samples. One hundred and twelve clinical samples from England; previously shown to be positive for EVs, were analyzed. There was high concordance between the results obtained by the new NGS approach and those from the conventional Sanger method used originally with agreement in the serotypes identified in the 83 samples that were typed by both methods. The sensitivity and specificity of the NGS method compared to those of the conventional Sanger sequencing typing assay were 94.74% (95% confidence interval, 73.97% to 99.87%) and 97.85% (92.45% to 99.74%) for Enterovirus A, 93.75% (82.80% to 98.69%) and 89.06% (78.75% to 95.49%) for Enterovirus B, 100% (59.04% to 100%) and 98.10% (93.29% to 99.77%) for Enterovirus C, and 100% (75.29% to 100%) and 100% (96.34% to 100%) for Enterovirus D. The NGS method identified five EVs in previously untyped samples as well as additional viruses in some samples, indicating co-infection. This method can be easily expanded to generate whole-genome EV sequences as we show here for EV-D68. Information from capsid and whole-genome sequences is critical to help identifying the genetic basis for changes in viral properties and establishing accurate spatial-temporal associations between EV strains of public health relevance.


Assuntos
Proteínas do Capsídeo/genética , Infecções por Enterovirus/virologia , Enterovirus/classificação , Enterovirus/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Sequenciamento Completo do Genoma , Inglaterra , Enterovirus/isolamento & purificação , Infecções por Enterovirus/sangue , Infecções por Enterovirus/líquido cefalorraquidiano , Fezes/virologia , Genoma Viral , Humanos , Filogenia , RNA Viral/genética , Sensibilidade e Especificidade , Sorogrupo
20.
mSystems ; 6(3): e0035321, 2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34128696

RESUMO

SARS-CoV-2 variants with multiple amino acid mutations in the spike protein are emerging in different parts of the world, raising concerns regarding their possible impact on human immune response and vaccine efficacy against the virus. Recently, a variant named lineage B.1.1.7 was detected and shown to be rapidly spreading across the UK since November 2020. As surveillance for these SARS-CoV-2 variants of concern (VOCs) becomes critical, we have investigated the use of environmental surveillance (ES) for the rapid detection and quantification of B.1.1.7 viruses in sewage as a way of monitoring its expansion that is independent on the investigation of identified clinical cases. Next-generation sequencing analysis of amplicons synthesized from sewage concentrates revealed the presence of B.1.1.7 mutations in viral sequences, first identified in a sample collected in London on 10 November 2020 and shown to rapidly increase in frequency to >95% in January 2021, in agreement with clinical data over the same period. We show that ES can provide an early warning of VOCs becoming prevalent in the population and that, as well as B.1.1.7, our method can detect VOCs B.1.351 and P.1, first identified in South Africa and Brazil, respectively, and other viruses carrying critical spike mutation E484K, known to have an effect on virus antigenicity. Although we did not detect such mutation in viral RNAs from sewage, we did detect mutations at amino acids 478, 490, and 494, located close to amino acid 484 in the spike protein structure and known to also have an effect on antigenicity. IMPORTANCE The recent appearance and growth of new SARS-CoV-2 variants represent a major challenge for the control of the COVID-19 pandemic. These variants of concern contain mutations affecting antigenicity, which raises concerns on their possible impact on human immune response to the virus and vaccine efficacy against them. Here, we show how environmental surveillance for SARS-CoV-2 can be used to help us understand virus transmission patterns and provide an early warning of variants becoming prevalent in the population. We describe the detection and quantification of variant B.1.1.7, first identified in southeast England in sewage samples from London (UK) before widespread transmission of this variant was obvious from clinical cases. Variant B.1.1.7 was first detected in a sample from early November 2020, with the frequency of B.1.1.7 mutations detected in sewage rapidly increasing to >95% in January 2021, in agreement with increasing SARS-CoV-2 infections associated with B.1.1.7 viruses.

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