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During a measles virus (MeV) epidemic in 2009 in South Africa, measles inclusion body encephalitis (MIBE) was identified in several HIV-infected patients. Years later, children are presenting with subacute sclerosing panencephalitis (SSPE). To investigate the features of established MeV neuronal infections, viral sequences were analyzed from brain tissue samples of a single SSPE case and compared with MIBE sequences previously obtained from patients infected during the same epidemic. Both the SSPE and the MIBE viruses had amino acid substitutions in the ectodomain of the F protein that confer enhanced fusion properties. Functional analysis of the fusion complexes confirmed that both MIBE and SSPE F protein mutations promoted fusion with less dependence on interaction by the viral receptor-binding protein with known MeV receptors. While the SSPE F required the presence of a homotypic attachment protein, MeV H, in order to fuse, MIBE F did not. Both F proteins had decreased thermal stability compared to that of the corresponding wild-type F protein. Finally, recombinant viruses expressing MIBE or SSPE fusion complexes spread in the absence of known MeV receptors, with MIBE F-bearing viruses causing large syncytia in these cells. Our results suggest that alterations to the MeV fusion complex that promote fusion and cell-to-cell spread in the absence of known MeV receptors is a key property for infection of the brain.IMPORTANCE Measles virus can invade the central nervous system (CNS) and cause severe neurological complications, such as MIBE and SSPE. However, mechanisms by which MeV enters the CNS and triggers the disease remain unclear. We analyzed viruses from brain tissue of individuals with MIBE or SSPE, infected during the same epidemic, after the onset of neurological disease. Our findings indicate that the emergence of hyperfusogenic MeV F proteins is associated with infection of the brain. We also demonstrate that hyperfusogenic F proteins permit MeV to enter cells and spread without the need to engage nectin-4 or CD150, known receptors for MeV that are not present on neural cells.
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Vírus do Sarampo/genética , Panencefalite Esclerosante Subaguda/genética , Proteínas Virais de Fusão/genética , Substituição de Aminoácidos , Animais , Encéfalo/virologia , Moléculas de Adesão Celular/metabolismo , Chlorocebus aethiops , Epidemias , Feminino , Genótipo , Células Gigantes/virologia , Células HEK293 , Humanos , Masculino , Sarampo/epidemiologia , Sarampo/metabolismo , Sarampo/virologia , Mutação , Neurônios/virologia , África do Sul , Panencefalite Esclerosante Subaguda/virologia , Células Vero , Proteínas Virais de Fusão/metabolismoRESUMO
BACKGROUND: Human enteroviruses (HEVs) are common causal agents of aseptic meningitis in young children. Laboratory and syndromic surveillance during December 2015 and January 2016 noted an unusually high number of paediatric aseptic meningitis cases at a hospital in Mossel Bay, Western Cape Province, South Africa. HEV was detected in clinical samples, prompting an outbreak investigation. METHODS: Epidemiological investigations were conducted to ascertain possible linkage between cases. Amplification, sequencing and phylogenetic analysis of the 5'UTR and VP1 regions was undertaken to determine the HEV serotype associated with the outbreak as well as other cases of aseptic meningitis in the area in the preceding 6 weeks. RESULTS: Over the 2-month period, 63 CSF samples were available for testing. A total of 43 outbreak cases (68.3%) were observed, and the 26 (60.5%) that could be typed were coxsackie virus A9 (CVA9). Children attending three crèche facilities were epidemiologically linked, accounting for 60.5% (26/43) of the CVA9 cases. The majority of patients were under 10 years of age (55/63, 87.3%) and there was a male predominance (66%). Nucleotide sequence analysis of the 5'UTR and VP1 regions identified 2 lineages of CVA9 co-circulating during the outbreak, although the VP1 capsid protein sequence was identical as all nucleotide differences were synonymous. There was a unique isoleucine at position 64 and all outbreak viruses had a valine to threonine change in the hypervariable BC loop of VP1. Other HEV types circulating in the preceding period were echovirus 30 (n = 4), echovirus 5 (n = 3) and 1 each of echovirus 6, echovirus 9 and echovirus 15. CONCLUSION: CVA9 was identified as the pathogen responsible for the large outbreak of aseptic meningitis, with 2 distinct co-circulating lineages.
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Surtos de Doenças , Infecções por Enterovirus/epidemiologia , Enterovirus/genética , Enterovirus/isolamento & purificação , Meningite Viral/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Enterovirus/classificação , Enterovirus Humano B/genética , Infecções por Enterovirus/complicações , Infecções por Enterovirus/virologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Meningite Viral/virologia , Tipagem Molecular , Filogenia , RNA Viral/análise , Vigilância de Evento Sentinela , África do Sul/epidemiologia , Adulto JovemRESUMO
BACKGROUND: During 2009/10 a major measles epidemic caused by genotype B3 occurred in South Africa. Measles inclusion body encephalitis (MIBE) was diagnosed in a number of highly immuno-compromised HIV patients. The diagnosis was based on typical clinical and MRI findings and positive measles virus PCR in brain or CSF.To characterize the brain virus, nucleoprotein, matrix, fusion and haemagglutinin genes from 4 cases was compared with virus from acutely infected patients. METHODS: cDNA was synthesized using random primers and viral genes were amplified by nested RT-PCR. PCR products were sequenced in the forward and reverse direction and a contig of each gene was created. Sequences were aligned with reference sequences from GenBank and other local sequences. RESULTS: Brain virus was very similar to the South African epidemic virus. Features characteristic of persistent measles virus in the brain were absent. Mutation frequency in brain virus was similar to epidemic virus and had the same substitution preference (U to C and C to U). The virus of 2 patients had the same L454W mutation in the fusion protein. CONCLUSION: The brain virus was very similar to the epidemic strain. The relatively few mutations probably reflect the short time from infection to brain disease in these highly immuno-compromised patients.
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Encéfalo/virologia , Vírus do Sarampo/genética , Vírus do Sarampo/isolamento & purificação , RNA Viral/genética , Panencefalite Esclerosante Subaguda/virologia , Adolescente , Adulto , Análise por Conglomerados , Feminino , Humanos , Masculino , Dados de Sequência Molecular , Taxa de Mutação , Filogenia , Mutação Puntual , Reação em Cadeia da Polimerase , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Análise de Sequência de DNA , África do Sul , Proteínas Virais/genética , Adulto JovemRESUMO
The epidemiology of human parainfluenza viruses (HPIV), particularly its role as a cause of acute respiratory infection (ARI) in infants, has not been formally studied in South Africa. We evaluated HPIV prevalence in diagnostic samples from hospitalized children from public sector hospitals in the Western Cape between 2014 and 2022. HPIV infection was detected in 2-10% of patients, with the majority of infections detected in children less than 1 year of age. Prior to 2020, HPIV 4 (40%) and HPIV 3 (34%) were the most prevalent types, with seasonal peaks in late winter/spring for HPIV 3 and autumn/winter for HPIV 4. HPIV 4A and 4B co-circulated during the seasonal activity between 2014 and 2017. Pandemic restrictions in 2020 had a profound effect on HPIV circulation and the rebound was dominated by waves of HPIV 3, accounting for 66% of detections and a sustained decline in the circulation of HPIV 1, 2 and 4. An immunity gap could account for the surge in HPIV 3 infections, but the decline in prior HPIV 4 dominance is unexplained and requires further study.
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BACKGROUND: Infections caused by human rhinoviruses (HRVs) are important triggers of wheezing in young children. Wheezy illness has increasingly been recognised as an important cause of morbidity in African children, but there is little information on the contribution of HRV to this. The aim of this study was to determine the role of HRV as a cause of acute wheezing in South African children. METHODS: Two hundred and twenty children presenting consecutively at a tertiary children's hospital with a wheezing illness from May 2004 to November 2005 were prospectively enrolled. A nasal swab was taken and reverse transcription PCR used to screen the samples for HRV. The presence of human metapneumovirus, human bocavirus and human coronavirus-NL63 was assessed in all samples using PCR-based assays. A general shell vial culture using a pool of monoclonal antibodies was used to detect other common respiratory viruses on 26% of samples. Phylogenetic analysis to determine circulating HRV species was performed on a portion of HRV-positive samples. Categorical characteristics were analysed using Fisher's Exact test. RESULTS: HRV was detected in 128 (58.2%) of children, most (72%) of whom were under 2 years of age. Presenting symptoms between the HRV-positive and negative groups were similar. Most illness was managed with ambulatory therapy, but 45 (35%) were hospitalized for treatment and 3 (2%) were admitted to intensive care. There were no in-hospital deaths. All 3 species of HRV were detected with HRV-C being the most common (52%) followed by HRV-A (37%) and HRV-B (11%). Infection with other respiratory viruses occurred in 20/128 (16%) of HRV-positive children and in 26/92 (28%) of HRV-negative samples. CONCLUSION: HRV may be the commonest viral infection in young South African children with acute wheezing. Infection is associated with mild or moderate clinical disease.
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Coronavirus Humano NL63/isolamento & purificação , Bocavirus Humano/isolamento & purificação , Metapneumovirus/isolamento & purificação , Infecções por Picornaviridae/epidemiologia , Sons Respiratórios/diagnóstico , Animais , Pré-Escolar , Análise por Conglomerados , Feminino , Genótipo , Humanos , Lactente , Masculino , Mucosa Nasal/virologia , Filogenia , Infecções por Picornaviridae/diagnóstico , Infecções por Picornaviridae/virologia , Reação em Cadeia da Polimerase , RNA Viral/genética , África do Sul/epidemiologia , Cultura de VírusRESUMO
BACKGROUND: Enteroviruses are amongst the most common causes of aseptic meningitis. Between November 2018 and May 2019, an outbreak of enterovirus-associated aseptic meningitis cases was noted in the Western and Eastern Cape Provinces, South Africa. OBJECTIVES: To describe the epidemiology and phylogeography of enterovirus infections during an aseptic meningitis outbreak in the Western and Eastern Cape Provinces of South Africa. METHODS: Cerebrospinal fluid samples from suspected cases were screened using a polymerase chain reaction targeting the 5'UTR. Confirmed enterovirus-associated meningitis samples underwent molecular typing through species-specific VP1/VP2 primers and pan-species VP1 primers. RESULTS: Between November 2018 and May 2019, 3497 suspected cases of aseptic meningitis were documented in the Western and Eastern Cape Provinces. Median age was 8 years (range 0-61), interquartile range (IQR=4-13 years), 405/735 (55%) male. 742/3497 (21%) cases were laboratory - confirmed enterovirus positive by routine diagnostic PCR targeting the 5'UTR. 128/742 (17%) underwent molecular typing by VP1 gene sequencing. Echovirus 4 (E4) was detected in 102/128 (80%) cases. Echovirus 9 was found in 7%, Coxsackievirus A13 in 3%. 10 genotypes contributed to the remaining 10% of cases. Synonymous mutations were found in most cases, with sporadic amino acid changes in 13 (12.7%) cases. CONCLUSION: The aseptic meningitis outbreak was associated with echovirus 4. Stool samples are valuable for molecular typing in CSF confirmed EV-associated aseptic meningitis.
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Infecções por Enterovirus , Enterovirus , Meningite Asséptica , Adolescente , Adulto , Criança , Pré-Escolar , Surtos de Doenças , Enterovirus/genética , Enterovirus Humano B/genética , Infecções por Enterovirus/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Meningite Asséptica/epidemiologia , Pessoa de Meia-Idade , Filogenia , RNA Viral/genética , África do Sul/epidemiologia , Adulto JovemRESUMO
Parvovirus B19 comprises three distinct genotypes (1, 2, and 3). The distribution of B19 genotypes has not before been examined in South Africa. Two hundred thirty-nine laboratory samples submitted to a diagnostic virology laboratory for parvovirus DNA detection were analyzed retrospectively. Of the 53 PCR-positive samples investigated, 40 (75.4%) were identified as genotype 1 by genotype-specific PCR or consensus NS1 PCR and sequencing and 3 (5.7%) as genotype 2 and 10 (18.9%) as genotype 3 by analysis of NS1 sequences. Furthermore, phylogenetic analysis identified two genotype 1 sequences which were distinct from the previously described genotypes 1A and 1B. Interestingly, a genotype 2 virus was detected in the serum of an 11-year-old child, providing evidence for its recent circulation. This is the first study to demonstrate the concurrent circulation of all three genotypes of B19 in South Africa and the provisional identification of a novel subtype of genotype 1. The implications of parvovirus B19 variation are discussed.
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Infecções por Parvoviridae/epidemiologia , Infecções por Parvoviridae/virologia , Parvovirus B19 Humano/classificação , Parvovirus B19 Humano/genética , Análise por Conglomerados , Primers do DNA/genética , DNA Viral/química , DNA Viral/genética , Genótipo , Humanos , Epidemiologia Molecular , Dados de Sequência Molecular , Parvovirus B19 Humano/isolamento & purificação , Filogenia , Reação em Cadeia da Polimerase/métodos , Estudos Retrospectivos , Análise de Sequência de DNA , Homologia de Sequência , África do Sul/epidemiologiaRESUMO
Sub-Saharan Africa has approximately 10.15 million people viraemic with chronic hepatitis C virus infection, extensive genotype and sub-genotype diversity is present, in addition to novel hepatitis C genotypes. Many of the unusual genotypes have extensive baseline resistance associated substitutions with direct acting antiviral therapy treatment outcome data, limited. We report a patient found to have a novel genotype 7b variant with extensive baseline resistance associated substitutions. There is a clear need for a better understanding of the virological characteristics of hepatitis C populations in sub-Saharan Africa to guide best optimal treatment decisions in national hepatitis C elimination programmes.
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Antivirais/administração & dosagem , Hepacivirus/genética , Hepatite C Crônica/diagnóstico , África Subsaariana , Idoso , Farmacorresistência Viral , Feminino , Genótipo , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/virologia , HumanosRESUMO
The SARS-CoV-2 pandemic has resulted in shortages of both critical reagents for nucleic acid purification and highly trained staff as supply chains are strained by high demand, public health measures and frequent quarantining and isolation of staff. This created the need for alternate workflows with limited reliance on specialised reagents, equipment and staff. We present here the validation and implementation of such a workflow for preparing samples for downstream SARS-CoV-2 RT-PCR using liquid handling robots. The rapid sample preparation technique evaluated, which included sample centrifugation and heating prior to RT-PCR, showed a 97.37% (95% CI: 92.55-99.28%) positive percent agreement and 97.30% (95% CI: 90.67-99.52%) negative percent agreement compared to nucleic acid purification-based testing. This method was subsequently adopted as the primary sample preparation method in the Groote Schuur Hospital Virology Diagnostic Laboratory in Cape Town, South Africa.
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Betacoronavirus/genética , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Laboratórios Hospitalares , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Robótica/métodos , COVID-19 , Teste para COVID-19 , Infecções por Coronavirus/virologia , Humanos , Pandemias , Pneumonia Viral/virologia , RNA Viral/genética , Reprodutibilidade dos Testes , SARS-CoV-2 , Sensibilidade e Especificidade , África do Sul/epidemiologia , Manejo de EspécimesRESUMO
BACKGROUND: Detection and quantification of hepatitis C virus (HCV) RNA is integral to diagnostic and therapeutic regimens. All molecular assays target the viral 5'-noncoding region (5'-NCR), and all show genotype-dependent variation of sensitivities and viral load results. Non-western HCV genotypes have been under-represented in evaluation studies. An alternative diagnostic target region within the HCV genome could facilitate a new generation of assays. METHODS AND FINDINGS: In this study we determined by de novo sequencing that the 3'-X-tail element, characterized significantly later than the rest of the genome, is highly conserved across genotypes. To prove its clinical utility as a molecular diagnostic target, a prototype qualitative and quantitative test was developed and evaluated multicentrically on a large and complete panel of 725 clinical plasma samples, covering HCV genotypes 1-6, from four continents (Germany, UK, Brazil, South Africa, Singapore). To our knowledge, this is the most diversified and comprehensive panel of clinical and genotype specimens used in HCV nucleic acid testing (NAT) validation to date. The lower limit of detection (LOD) was 18.4 IU/ml (95% confidence interval, 15.3-24.1 IU/ml), suggesting applicability in donor blood screening. The upper LOD exceeded 10(-9) IU/ml, facilitating viral load monitoring within a wide dynamic range. In 598 genotyped samples, quantified by Bayer VERSANT 3.0 branched DNA (bDNA), X-tail-based viral loads were highly concordant with bDNA for all genotypes. Correlation coefficients between bDNA and X-tail NAT, for genotypes 1-6, were: 0.92, 0.85, 0.95, 0.91, 0.95, and 0.96, respectively; X-tail-based viral loads deviated by more than 0.5 log10 from 5'-NCR-based viral loads in only 12% of samples (maximum deviation, 0.85 log10). The successful introduction of X-tail NAT in a Brazilian laboratory confirmed the practical stability and robustness of the X-tail-based protocol. The assay was implemented at low reaction costs (US$8.70 per sample), short turnover times (2.5 h for up to 96 samples), and without technical difficulties. CONCLUSION: This study indicates a way to fundamentally improve HCV viral load monitoring and infection screening. Our prototype assay can serve as a template for a new generation of viral load assays. Additionally, to our knowledge this study provides the first open protocol to permit industry-grade HCV detection and quantification in resource-limited settings.
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Regiões 5' não Traduzidas/genética , Hepacivirus/isolamento & purificação , Hepatite C/diagnóstico , RNA Viral/sangue , Carga Viral/métodos , Sequência de Bases , Genoma Viral/genética , Genótipo , Hepacivirus/genética , Hepatite C/virologia , Humanos , Dados de Sequência Molecular , RNA Viral/genéticaRESUMO
BACKGROUND: Human pegivirus-1 (HPgV-1) infection in the brain has not been extensively examined and its association with disease remains unconfirmed. In a high throughput sequencing study to look for infectious agents that could play a role in HIV-associated neurocognitive disorder (HAND), this virus was detected in 3 of 8 CSF samples. OBJECTIVES: To determine the significance of this finding, additional patients were screened and the viral load and viral diversity in blood and CSF were examined. STUDY DESIGN: Nested PCR of the viral 5'NCR region was performed on blood and CSF pairs from 16 HAND patients. PCR products were cloned, sequenced and analysed to determine viral diversity in blood and CSF. HPgV-1 viral loads were determined in paired blood and CSF of 2 patients by digital droplet PCR. Nested PCR was also performed on CSF samples from patients with other brain disorders. RESULTS: Virus was detected in both blood and CSF in 3 of 16 HAND patients. Viral loads were very high in blood (8.81 and 10.56 log copies/ml) and 4-5 logs lower in CSF (4.68 and 5.84 log copies/ml). Sequence analysis of 5'NCR clones in blood and CSF showed limited variation. The dominant viral variant (based on clonal sequence identity) in blood and CSF was usually identical. HPgV-1 was detected in CSF from patients with other brain disorders at a similar frequency (15% versus 18.75% in HAND patients). CONCLUSION: While several studies have reported HPgV-1 detection in CSF of patients with brain disease, this is the only study that has examined both blood and CSF compartments simultaneously. Our findings show that virus in CSF always coincided with viraemia and levels were 4-5 logs higher in blood. While a rare, but specific brain tropism cannot be excluded, blood is the more probable source of virus in HAND patients.
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Líquido Cefalorraquidiano/virologia , Infecções por Flaviviridae/virologia , Vírus GB C/isolamento & purificação , Infecções por HIV/complicações , Transtornos Neurocognitivos/virologia , Viremia , Adulto , Feminino , Infecções por Flaviviridae/epidemiologia , Vírus GB C/genética , Infecções por HIV/sangue , Infecções por HIV/líquido cefalorraquidiano , Infecções por HIV/virologia , HIV-1/genética , HIV-1/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , Reação em Cadeia da Polimerase , RNA Viral/líquido cefalorraquidiano , Carga ViralRESUMO
Introduction. Chicken anaemia virus, CAV, was until recently the only member of the Gyrovirus genus. 6 novel gyroviruses, AGV2, HGyV1, and GyV3-6, have since been discovered in human and chicken samples. Methods. PCR amplification of the VP2 gene was used to detect AGV2/HGyV1, GyV3, and CAV in a range of clinical samples including stool, respiratory, CSF, and HIV-positive plasma. Screening of fresh local chicken meat was also performed. Results. AGV2/HGyV1 or GyV3 was detected in stools from healthy children (17/49, 34.7%) and patients with diarrhoea (22/149, 14.8%). 1.2% (3/246) nasopharyngeal respiratory samples were positive. No AGV2/HGyV1 or GyV3 was detected in nasal swabs from wheezing patients, in CSF from patients with meningitis, and in HIVpositive plasma. CAV was found in 51% (25/49) of stools from healthy children and 16% (24/149) in diarrhoea samples. Screening of 28 chicken samples showed a higher prevalence of gyrovirus (20/28, 71%) compared to CAV (1/28, 3.6%). Phylogenetic analysis of the CAV VP1 gene showed South African sequences clustering with Brazilian isolates from genotypes D2 and A2. Conclusion. Novel gyroviruses, including CAV, are present in the South African population with diarrhoea and respiratory illness as well as in healthy children. Their presence suggests an origin from chicken meat consumption.
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BACKGROUND: The prevalence of myocarditis and cardiotropic viral infection in human immunodeficiency virus (HIV)-associated cardiomyopathy is unknown in Africa. METHODS: Between April 2002 and December 2007, we compared the prevalence of myocarditis and cardiotropic viral genomes in HIV-associated cardiomyopathy cases with HIV-negative idiopathic dilated cardiomyopathy patients (i.e. negative controls for immunodeficiency) and heart transplant recipients (i.e. positive controls for immunodeficiency) who were seen at Groote Schuur Hospital, Cape Town, South Africa. Myocarditis was sought on endomyocardial biopsy using the imunohistological criteria of the World Heart Federation in 33 patients, 14 of whom had HIV-associated cardiomyopathy, eight with idiopathic dilated cardiomyopathy and 11 heart transplant recipients. RESULTS: Myocarditis was present in 44% of HIV-associated cardiomyopathy cases, 36% of heart transplant recipients, and 25% of participants with idiopathic dilated cardiomyopathy. While myocarditis was acute in 50% of HIV- and heart transplant-associated myocarditis, it was chronic in all those with idiopathic dilated cardiomyopathy. Cardiotropic viral infection was present in all HIV-associated cardiomyopathy and idiopathic dilated cardiomyopathy cases, and in 90% of heart transplant recipients. Multiple viruses were identified in the majority of cases, with HIV-associated cardiomyopathy, heart transplant recipients and idiopathic dilated cardiomyopathy patients having an average of 2.5, 2.2 and 1.1 viruses per individual, respectively. CONCLUSIONS: Acute myocarditis was present in 21% of cases of HIV-associated cardiomyopathy, compared to none of those with idiopathic dilated cardiomyopathy. Infection with multiple cardiotropic viruses may be ubiquitous in Africans, with a greater burden of infection in acquired immunodeficiency states.
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Cardiomiopatias/epidemiologia , Cardiomiopatia Dilatada/epidemiologia , Infecções por HIV/epidemiologia , Transplante de Coração/efeitos adversos , Miocardite/epidemiologia , Adulto , Idoso , Biópsia , População Negra , Cardiomiopatias/diagnóstico , Cardiomiopatias/imunologia , Cardiomiopatias/virologia , Cardiomiopatia Dilatada/diagnóstico , Cardiomiopatia Dilatada/imunologia , Estudos de Casos e Controles , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/imunologia , Humanos , Hospedeiro Imunocomprometido , Masculino , Pessoa de Meia-Idade , Miocardite/diagnóstico , Miocardite/imunologia , Miocardite/virologia , Projetos Piloto , Prevalência , Prognóstico , Fatores de Risco , África do Sul/epidemiologiaRESUMO
Forty strains of H. fennelliae collected from paediatric blood and stool samples over an 18 year period at a children's hospital in Cape Town, South Africa, were amplified by PCR of the 16S rRNA. Two distinct genotypes of H. fennelliae were identified based on the phylogenetic analysis. This was confirmed by sequencing a portion of the beta subunit of the RNA polymerase (rpoB) gene. All isolates from South Africa clustered with a proposed novel Helicobacter strain (accession number AF237612) isolated in Australia, while three H. fennelliae type strains from the northern hemisphere, NCTC 11612, LMG 7546 and CCUG 18820, formed a separate branch. A large (355bp) highly conserved intervening sequence (IVS) in the 16S rRNA was found in all isolates. Predicted secondary structures of the IVS from the 16S rRNA and 23S rRNA were characterised by a primary stem structure formed by base pairing of the 3' and 5' ends and internal loops and stems. This phylogenetic analysis is the largest undertaken of H. fennelliae. The South African H. fennelliae isolates are closely related to an Australian isolate previously reported to be a possible novel species of Helicobacter. This study suggests that the latter is strain of H. fennelliae.
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BACKGROUND: Human coronavirus NL63 (HCoV-NL63) is a novel respiratory virus which is associated with respiratory tract infections in children. OBJECTIVE: To determine the role of HCoV-NL63 in infants and young children hospitalised with acute respiratory tract infections (ARI) in Cape Town, South Africa. METHODS: Respiratory specimens were collected from 1055 infants and young children hospitalised with ARI in 2003-2004. Samples were screened by RT-PCR to detect HCoV-NL63 and human metapneumovirus (hMPV). Standard shell vial culture and immunofluoresence was used to detect the common respiratory viruses including RSV, influenza A and B viruses, parainfluenza viruses 1, 2, 3, adenovirus and CMV. RESULTS: A respiratory virus was found in 401/1055 (38.0%) samples. HCoV-NL63 was detected in 9/1055 (0.85%) with peak activity during autumn (67%). Most patients had a diagnosis of pneumonia or lower respiratory tract infection (6/9; 67%). CONCLUSIONS: This is the first report of HCoV-NL63 infections in hospitalised children in Africa. During the 2-year period HCoV-NL63 played a minor role in ARI in children.
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Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Coronavirus/isolamento & purificação , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Adenoviridae/isolamento & purificação , Pré-Escolar , Citomegalovirus/isolamento & purificação , Feminino , Hospitalização , Humanos , Lactente , Masculino , Orthomyxoviridae/isolamento & purificação , Prevalência , Vírus Sinciciais Respiratórios/isolamento & purificação , Respirovirus/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , África do Sul/epidemiologia , Escarro/virologiaRESUMO
The role of the novel respiratory viruses, human metapneumovirus (hMPV), human coronavirus NL63 (HCoV NL63) and human bocavirus (HBoV), in wheezing illness in children has not been well studied, especially in Africa. The aim of this study was to investigate the prevalence of hMPV, HCoV NL63 and HBoV in South African children with acute wheezing. A prospective study of consecutive children presenting with acute wheezing to a pediatric hospital from May 2004 to November 2005 was undertaken. A nasal swab was taken for reverse transcription-polymerase chain reaction (RT-PCR) and PCR for hMPV, HCoV NL63 and HBoV; when positive, the genes were sequenced. Shell vial culture for RSV, influenza A and B viruses, adenovirus and parainfluenza viruses 1, 2, 3 was performed on every 5th sample. Two hundred and forty two nasal swabs were collected from 238 children (median age 12.4 months). A novel respiratory virus was found in 44/242 (18.2%). hMPV, HBoV, and HCoV NL63 was found in 20 (8.3%), 18 (7.4%), and 6 (2.4%) of samples, respectively. Fifteen of 59 (25%) samples were positive for other respiratory viruses. Viral co-infections, occurred in 6/242 (2.5%). Phylogenetic analysis showed co-circulation of hMPV and HCoV NL63 A and B lineages, although only HBoV genotype st2 was found. Viruses are an important cause of wheezing in preschool children; hMPV, HCoV NL63, and HBoV are less common than the usual respiratory pathogens.
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Bocavirus/isolamento & purificação , Infecções por Coronavirus/virologia , Coronavirus/isolamento & purificação , Metapneumovirus/isolamento & purificação , Infecções por Paramyxoviridae/virologia , Infecções por Parvoviridae/virologia , Sons Respiratórios/etiologia , Bocavirus/classificação , Bocavirus/genética , Pré-Escolar , Comorbidade , Coronavirus/classificação , Coronavirus/genética , Infecções por Coronavirus/epidemiologia , Feminino , Hospitais , Humanos , Lactente , Masculino , Metapneumovirus/classificação , Metapneumovirus/genética , Epidemiologia Molecular , Dados de Sequência Molecular , Nariz/virologia , Infecções por Paramyxoviridae/epidemiologia , Infecções por Parvoviridae/epidemiologia , Filogenia , Prevalência , Estudos Prospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Homologia de Sequência , África do Sul/epidemiologia , Cultura de VírusRESUMO
AIM: To describe the clinical presentation and outcomes of hospitalised patients infected with human metapneumovirus (hMPV) and human respiratory syncytial virus (hRSV) in a tertiary hospital in Cape Town, South Africa. METHODS: hMPV was identified in 17 respiratory specimens submitted for viral studies during the period 2001-2003. These patients' medical folders were retrospectively reviewed for clinical, radiological and laboratory data, together with a convenience sample of 20 hRSV-infected patients. RESULTS: hMPV-infected patients were older than those infected with hRSV (P = 0.04) and required a longer hospital stay (P = 0.02). Presenting clinical signs and symptoms were similar between groups. Fourteen (87.5%) hMPV- and 16 (80%) hRSV-infected patients presented with co-morbid and/or immunosuppressive conditions (P > or = 0.5). The most common abnormalities on chest radiographs in both groups were bronchial wall thickening, focal consolidation and atelectasis. Six (37.5%) hMPV- and 11 (55%) hRSV-infected patients required admission to the paediatric intensive care unit (P > 0.1) with five (31.3%) hMPV- and eight (40%) hRSV-infected patients requiring intubation and ventilation (P > 0.5). Three (18.7%) hMPV-patients and three (15%) hRSV-infected patients died during this admission (P > 0.5). All hMPV-infected patients who died had significant co-morbid conditions. CONCLUSIONS: These data confirm that hMPV is a significant respiratory pathogen in this setting, with similar presentation and outcome to hRSV infection. This is the largest report of hMPV infection causing significant morbidity, prolonged hospital stay and death, associated with underlying risk factors.
Assuntos
Metapneumovirus/isolamento & purificação , Avaliação de Resultados em Cuidados de Saúde , Infecções por Paramyxoviridae/diagnóstico , Infecções por Vírus Respiratório Sincicial/diagnóstico , Vírus Sinciciais Respiratórios/isolamento & purificação , Distribuição por Idade , Pré-Escolar , Comorbidade , Feminino , Hospitalização , Humanos , Lactente , Recém-Nascido , Unidades de Terapia Intensiva Pediátrica/estatística & dados numéricos , Masculino , Mucosa Nasal/virologia , Infecções por Paramyxoviridae/mortalidade , Infecções por Paramyxoviridae/terapia , Infecções por Vírus Respiratório Sincicial/mortalidade , Infecções por Vírus Respiratório Sincicial/terapia , África do SulRESUMO
BACKGROUND & AIMS: Molecular evolutionary analysis based on coalescent theory can provide important insights into epidemiologic processes worldwide. This approach was combined with analyses of the hepatitis C virus (HCV) epidemiologic-historical background and HCV-related hepatocellular carcinoma (HCC) in different countries. METHODS: The HCV gene sequences of 131 genotype 1b (HCV-1b) strains from Japan, 38 HCV-1a strains from the United States, 33 HCV-1b strains from Spain, 27 HCV-3a strains from the former Soviet Union (FSU), 47 HCV-4a strains from Egypt, 25 HCV-5a strains from South Africa, and 24 HCV-6a strains from Hong Kong isolated in this study and previous studies were analyzed. RESULTS: The coalescent analysis indicated that a transition from constant size to rapid exponential growth (spread time) occurred in Japan in the 1920s (HCV-1b), but not until the 1940s for the same genotype in Spain and other European countries. The spread time of HCV-1a in the United States was estimated to be in the 1960s; HCV-3a in the FSU, HCV-5a in South Africa, and HCV-6a in Hong Kong in the 1960s, mid-1950s, and late 1970s, respectively. Three different linear progression curves were determined by analysis of the relationship between HCV seroprevalence and HCC mortality in different geographic regions; a steep ascent indicated the greatest progression to HCC in Japan, a near horizontal line indicated the least progression in the United States and the FSU, and an intermediate slope was observed in Europe. CONCLUSIONS: These findings strongly suggest that the initial spread time of HCV is associated with the progression dynamics of HCC in each area, irrespective of genotype.