RESUMO
We report on a 2023 outbreak of severe hand, foot, and mouth disease in southern Vietnam caused by an emerging lineage of enterovirus A71 subgenogroup B5. Affected children were significantly older than those reported during previous outbreaks. The virus should be closely monitored to assess its potential for global dispersal.
Assuntos
Infecções por Enterovirus , Enterovirus , Doença de Mão, Pé e Boca , Criança , Humanos , Enterovirus/genética , Vietnã/epidemiologia , Doença de Mão, Pé e Boca/epidemiologia , Infecções por Enterovirus/epidemiologia , Extremidade Inferior , Antígenos ViraisRESUMO
Hand foot and mouth disease (HFMD) is caused by a variety of enteroviruses, and occurs in large outbreaks in which a small proportion of children deteriorate rapidly with cardiopulmonary failure. Determining which children are likely to deteriorate is difficult and health systems may become overloaded during outbreaks as many children require hospitalization for monitoring. Heart rate variability (HRV) may help distinguish those with more severe diseases but requires simple scalable methods to collect ECG data.We carried out a prospective observational study to examine the feasibility of using wearable devices to measure HRV in 142 children admitted with HFMD at a children's hospital in Vietnam. ECG data were collected in all children. HRV indices calculated were lower in those with enterovirus A71 associated HFMD compared to those with other viral pathogens.HRV analysis collected from wearable devices is feasible in a low and middle income country (LMIC) and may help classify disease severity in HFMD.
Assuntos
Enterovirus Humano A , Infecções por Enterovirus , Enterovirus , Doença de Mão, Pé e Boca , Criança , Humanos , Lactente , Doença de Mão, Pé e Boca/diagnóstico , Frequência Cardíaca , Estudos de Viabilidade , China/epidemiologiaRESUMO
Mpox was diagnosed in 2 women returning to Vietnam from the United Arab Emirates. The monkeypox viruses belonged to an emerging sublineage, A.2.1, distinct from B.1, which is responsible for the ongoing multicountry outbreak. Women could contribute to mpox transmission, and enhanced genomic surveillance is needed to clarify pathogen evolution.
Assuntos
Monkeypox virus , Mpox , Humanos , Feminino , Mpox/diagnóstico , Mpox/epidemiologia , Emirados Árabes Unidos/epidemiologia , Vietnã/epidemiologiaRESUMO
We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions.
Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , SARS-CoV-2/genética , Vietnã/epidemiologia , Surtos de DoençasRESUMO
Antibody response against nucleocapsid and spike proteins of SARS-CoV-2 in 11 persons with mild or asymptomatic infection rapidly increased after infection. At weeks 18-30 after diagnosis, all remained seropositive but spike protein-targeting antibody titers declined. These data may be useful for vaccine development.
Assuntos
COVID-19/imunologia , Imunidade Humoral , SARS-CoV-2/imunologia , Adolescente , Adulto , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Infecções Assintomáticas , COVID-19/sangue , COVID-19/virologia , Criança , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Proteínas do Nucleocapsídeo/sangue , Proteínas do Nucleocapsídeo/imunologia , Glicoproteína da Espícula de Coronavírus/sangue , Glicoproteína da Espícula de Coronavírus/imunologia , Fatores de Tempo , Vietnã , Adulto JovemRESUMO
We report a superspreading event of severe acute respiratory syndrome coronavirus 2 infection initiated at a bar in Vietnam with evidence of symptomatic and asymptomatic transmission, based on ministry of health reports, patient interviews, and whole-genome sequence analysis. Crowds in enclosed indoor settings with poor ventilation may be considered at high risk for transmission.
Assuntos
COVID-19/epidemiologia , COVID-19/transmissão , SARS-CoV-2 , Adulto , Busca de Comunicante , Aglomeração , Genoma Viral , Humanos , Masculino , Vietnã/epidemiologiaRESUMO
BACKGROUND: Since their emergence in Indonesia in 2005, 200 human infections with clade 2.1 highly pathogenic avian influenza A/H5N1 virus have been reported, associated with exceptionally high mortality (84%) compared to regions affected by other genetic clades of this virus. To provide potential clues towards understanding this high mortality, detailed clinical virological analyses were performed in specimens from 180 H5N1 patients, representing 90% of all Indonesian patients and 20% of reported H5N1-infected patients globally. METHODS: H5N1 RNA was quantified in available upper- and lower-respiratory tract specimens as well as fecal and blood samples from 180 patients with confirmed infection between 2005 and 2017. Mutations in the neuraminidase and M2 genes that confer resistance to oseltamivir and adamantanes were assessed. Fatal and nonfatal cases were compared. RESULTS: High viral RNA loads in nasal and pharyngeal specimens were associated with fatal outcome. Mortality increased over time during the study period, which correlated with increasing viral RNA loads on admission. Furthermore, the prevalence of amantadine resistance-conferring M2 mutations increased over time, and viral loads were higher in patients infected with viruses that harbored these mutations. Compared to observations from other regions, viral RNA was detected more frequently in feces (80%) and particularly in blood (85%), and antiviral responses to oseltamivir appeared less pronounced. CONCLUSIONS: These observations confirm the association of viral load with outcome of human H5N1 infections and suggest potential differences in virulence and antiviral responses to oseltamivir that may explain the exceptionally high mortality related to clade 2.1 H5N1 infections in Indonesia.
Assuntos
Antivirais , Virus da Influenza A Subtipo H5N1 , Influenza Aviária , Influenza Humana , Animais , Antivirais/uso terapêutico , Humanos , Indonésia/epidemiologia , Virus da Influenza A Subtipo H5N1/genética , Influenza Humana/epidemiologia , Neuraminidase , Oseltamivir/uso terapêuticoRESUMO
BACKGROUND: Little is known about the natural history of asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: We conducted a prospective study at a quarantine center for coronavirus disease 2019 in Ho Chi Minh City, Vietnam. We enrolled quarantined people with reverse-transcription polymerase chain reaction (RT-PCR)-confirmed SARS-CoV-2 infection, collecting clinical data, travel and contact history, and saliva at enrollment and daily nasopharyngeal/throat swabs (NTSs) for RT-PCR testing. We compared the natural history and transmission potential of asymptomatic and symptomatic individuals. RESULTS: Between 10 March and 4 April 2020, 14â 000 quarantined people were tested for SARS-CoV-2; 49 were positive. Of these, 30 participated in the study: 13 (43%) never had symptoms and 17 (57%) were symptomatic. Seventeen (57%) participants imported cases. Compared with symptomatic individuals, asymptomatic people were less likely to have detectable SARS-CoV-2 in NTS collected at enrollment (8/13 [62%] vs 17/17 [100%]; Pâ =â .02). SARS-CoV-2 RNA was detected in 20 of 27 (74%) available saliva samples (7 of 11 [64%] in the asymptomatic group and 13 of 16 [81%] in the symptomatic group; Pâ =â .56). Analysis of RT-PCR positivity probability showed that asymptomatic participants had faster viral clearance than symptomatic participants (Pâ <â .001 for difference over the first 19 days). This difference was most pronounced during the first week of follow-up. Two of the asymptomatic individuals appeared to transmit SARS-CoV-2 to 4 contacts. CONCLUSIONS: Asymptomatic SARS-CoV-2 infection is common and can be detected by analysis of saliva or NTSs. The NTS viral loads fall faster in asymptomatic individuals, but these individuals appear able to transmit the virus to others.
Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Estudos Prospectivos , RNA Viral , Vietnã/epidemiologiaRESUMO
Hand, foot and mouth disease (HFMD) is an emerging infection with pandemic potential. Knowledge of neutralizing antibody responses among its pathogens is essential to inform vaccine development and epidemiologic research. We used 120 paired-plasma samples collected at enrollment and >7 days after the onset of illness from HFMD patients infected with enterovirus A71 (EV-A71), coxsackievirus A (CVA) 6, CVA10, and CVA16 to study cross neutralization. For homotypic viruses, seropositivity increased from <60% at enrollment to 97%-100% at follow-up, corresponding to seroconversion rates of 57%-93%. Seroconversion for heterotypic viruses was recorded in only 3%-23% of patients. All plasma samples from patients infected with EV-A71 subgenogroup B5 could neutralize the emerging EV-A71 subgenogroup C4. Collectively, our results support previous reports about the potential benefit of EV-A71 vaccine but highlight the necessity of multivalent vaccines to control HFMD.
Assuntos
Anticorpos Neutralizantes/imunologia , Enterovirus/imunologia , Doença de Mão, Pé e Boca/epidemiologia , Criança , Pré-Escolar , Feminino , Doença de Mão, Pé e Boca/sangue , Doença de Mão, Pé e Boca/prevenção & controle , Doença de Mão, Pé e Boca/virologia , Humanos , Lactente , Recém-Nascido , Masculino , Vietnã/epidemiologia , Vacinas ViraisRESUMO
We investigated enterovirus A71-associated hand, foot and mouth disease in Vietnam and found that, after replacing subgenogroup C4 in 2013, B5 remained the leading cause of this disease. In contrast with previous observations, this switch did not result in an explosive outbreak, and B5 evolution was driven by negative selection.
Assuntos
Enterovirus Humano A/genética , Doença de Mão, Pé e Boca/virologia , Doença de Mão, Pé e Boca/epidemiologia , Humanos , Vietnã/epidemiologiaRESUMO
Community-acquired (CA) sepsis is a major public health problem worldwide, yet the etiology remains unknown for >50% of the patients. Here we applied metagenomic next-generation sequencing (mNGS) to characterize the human virome in 492 clinical samples (384 sera, 92 pooled nasal and throat swabs, 10 stools, and 6 cerebrospinal fluid samples) from 386 patients (213 adults and 173 children) presenting with CA sepsis who were recruited from 6 hospitals across Vietnam between 2013 and 2015. Specific monoplex PCRs were used subsequently to confirm the presence of viral sequences detected by mNGS. We found sequences related to 47 viral species belonging to 21 families in 358 of 386 (93%) patients, including viruses known to cause human infections. After PCR confirmation, human viruses were found in 52 of 386 patients (13.4%); picornavirus (enteroviruses [n = 14], rhinovirus [n = 5], and parechovirus [n = 2]), hepatitis B virus (n = 10), cytomegalovirus (n = 9), Epstein-Barr virus (n = 5), and rotavirus A (n = 3) were the most common viruses detected. Recently discovered viruses were also found (gemycircularvirus [n = 5] and WU polyomavirus, Saffold virus, salivirus, cyclovirus-VN, and human pegivirus 2 [HPgV2] [n, 1 each]), adding to the growing literature about the geographic distribution of these novel viruses. Notably, sequences related to numerous viruses not previously reported in human tissues were also detected. To summarize, we identified 21 viral species known to be infectious to humans in 52 of 386 (13.4%) patients presenting with CA sepsis of unknown cause. The study, however, cannot directly impute sepsis causation to the viruses identified. The results highlight the fact that it remains a challenge to establish the causative agents in CA sepsis patients, especially in tropical settings such as Vietnam.
Assuntos
Infecções Comunitárias Adquiridas/virologia , Sepse/virologia , Viroses/virologia , Vírus/classificação , Vírus/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Povo Asiático , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/epidemiologia , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Hospitais , Humanos , Lactente , Recém-Nascido , Masculino , Metagenômica , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Sepse/epidemiologia , Vietnã/epidemiologia , Viroses/epidemiologia , Vírus/genética , Adulto JovemRESUMO
We report human pegivirus 2 (HPgV-2) infection in Vietnam. We detected HPgV-2 in some patients with hepatitis C virus/HIV co-infection but not in patients with HIV or hepatitis A, B, or C virus infection, nor in healthy controls. HPgV-2 strains in Vietnam are phylogenetically related to global strains.
Assuntos
Coinfecção/virologia , Infecções Comunitárias Adquiridas/epidemiologia , Infecções por Flaviviridae/virologia , Flaviviridae/isolamento & purificação , Infecções por HIV/complicações , Hepatite C/complicações , Adulto , Infecções Comunitárias Adquiridas/virologia , Demografia , Flaviviridae/genética , Infecções por Flaviviridae/complicações , Infecções por Flaviviridae/epidemiologia , Infecções por HIV/epidemiologia , Infecções por HIV/virologia , Hepatite C/epidemiologia , Hepatite C/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Multiplex , Filogenia , Prevalência , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Vietnã/epidemiologiaRESUMO
Hand, foot and mouth disease (HFMD) is a major public health issue in Asia and has global pandemic potential. Coxsackievirus A6 (CV-A6) was detected in 514/2,230 (23%) of HFMD patients admitted to 3 major hospitals in southern Vietnam during 2011-2015. Of these patients, 93 (18%) had severe HFMD. Phylogenetic analysis of 98 genome sequences revealed they belonged to cluster A and had been circulating in Vietnam for 2 years before emergence. CV-A6 movement among localities within Vietnam occurred frequently, whereas viral movement across international borders appeared rare. Skyline plots identified fluctuations in the relative genetic diversity of CV-A6 corresponding to large CV-A6-associated HFMD outbreaks worldwide. These data show that CV-A6 is an emerging pathogen and emphasize the necessity of active surveillance and understanding the mechanisms that shape the pathogen evolution and emergence, which is essential for development and implementation of intervention strategies.
Assuntos
Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/virologia , Infecções por Coxsackievirus/epidemiologia , Infecções por Coxsackievirus/virologia , Enterovirus Humano A , Doença de Mão, Pé e Boca/epidemiologia , Doença de Mão, Pé e Boca/virologia , Adolescente , Adulto , Criança , Enterovirus Humano A/classificação , Enterovirus Humano A/genética , Enterovirus Humano A/isolamento & purificação , Feminino , Genoma Viral , Genômica/métodos , Humanos , Masculino , Filogenia , Filogeografia , Vietnã/epidemiologia , Sequenciamento Completo do Genoma , Adulto JovemRESUMO
BACKGROUND: Enteroviruses are the most common causative agents of human illness. Enteroviruses have been associated with regional and global epidemics, recently, including with severe disease (Enterovirus A71 and D68), and are of interest as emerging viruses. Here, we typed Enterovirus A-D (EV) from central nervous system (CNS) and respiratory infections in Viet Nam. METHODS: Data and specimens from prospective observational clinical studies conducted between 1997 and 2010 were used. Species and serotypes were determined using type-specific RT-PCR and viral protein 1 or 4 (VP1, VP4) sequencing. RESULTS: Samples from patients with CNS infection (51 children - 10 CSF and 41 respiratory/rectal swabs) and 28 adults (28 CSF) and respiratory infection (124 children - 124 respiratory swabs) were analysed. Twenty-six different serotypes of the four Enterovirus species (A-D) were identified, including EV-A71 and EV-D68. Enterovirus B was associated with viral meningitis in children and adults. Hand, foot and mouth disease associated Enteroviruses A (EV-A71 and Coxsackievirus [CV] A10) were detected in children with encephalitis. Diverse serotypes of all four Enterovirus species were found in respiratory samples, including 2 polio-vaccine viruses, but also 8 CV-A24 and 8 EV-D68. With the exception of EV-D68, the relevance of these viruses in respiratory infection remains unknown. CONCLUSION: We describe the diverse spectrum of enteroviruses from patients with CNS and respiratory infections in Viet Nam between 1997 and 2010. These data confirm the global circulation of Enterovirus genera and their associations and are important for clinical diagnostics, patient management, and outbreak response.
Assuntos
Infecções do Sistema Nervoso Central/epidemiologia , Infecções do Sistema Nervoso Central/virologia , Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/virologia , Enterovirus/classificação , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Adolescente , Adulto , Infecções do Sistema Nervoso Central/diagnóstico , Infecções do Sistema Nervoso Central/história , Criança , Pré-Escolar , Enterovirus/genética , Enterovirus/isolamento & purificação , Infecções por Enterovirus/diagnóstico , Infecções por Enterovirus/história , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , História do Século XX , História do Século XXI , Humanos , Lactente , Masculino , Filogenia , Vigilância da População , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/história , Estações do Ano , Análise de Sequência de DNA , Sorogrupo , Vietnã/epidemiologia , Adulto JovemRESUMO
Since January 2018, over 53,000 hospitalisations and six deaths due to hand, foot and mouth disease (HFMD) have occurred across Vietnam with most cases from September onward. In a large tertiary referral hospital, Ho Chi Minh City, enterovirus A71 subgenogroup C4 was predominant, while B5 was only sporadically detected. The re-emergence of C4 after causing a severe HFMD outbreak with > 200 deaths in 2011-12 among susceptible young children raises concern of another impending severe outbreak.
Assuntos
Surtos de Doenças , Enterovirus Humano A/isolamento & purificação , Infecções por Enterovirus/epidemiologia , Genoma Viral/genética , Doença de Mão, Pé e Boca/epidemiologia , Doença de Mão, Pé e Boca/virologia , Hospitalização/estatística & dados numéricos , Criança , Pré-Escolar , Enterovirus Humano A/classificação , Enterovirus Humano A/genética , Infecções por Enterovirus/diagnóstico , Epidemias , Feminino , Doença de Mão, Pé e Boca/genética , Humanos , Lactente , Masculino , Análise de Sequência de RNA , Vietnã/epidemiologiaRESUMO
We utilized polymerase chain reaction (PCR) to demonstrate that Angiostrongylus cantonensis was responsible for 67.3% of 55 cases of eosinophilic meningitis from a cohort of 1,690 adult patients with CNS infection at a tertiary hospital in southern Vietnam. Longer duration of illness, depressed consciousness, and peripheral blood eosinophilia were associated with PCR positivity.
Assuntos
Angiostrongylus cantonensis/isolamento & purificação , Eosinofilia/parasitologia , Meningite/parasitologia , Infecções por Strongylida/parasitologia , Adolescente , Adulto , Angiostrongylus cantonensis/genética , Animais , Estudos de Coortes , Eosinofilia/epidemiologia , Feminino , Humanos , Masculino , Meningite/epidemiologia , Reação em Cadeia da Polimerase , Estudos Prospectivos , Infecções por Strongylida/diagnóstico , Infecções por Strongylida/epidemiologia , Centros de Atenção Terciária , Vietnã/epidemiologia , Adulto JovemRESUMO
UNLABELLED: Enterovirus A71 (EV-A71) is a major cause of hand, foot, and mouth disease (HFMD) and is particularly prevalent in parts of Southeast Asia, affecting thousands of children and infants each year. Revealing the evolutionary and epidemiological dynamics of EV-A71 through time and space is central to understanding its outbreak potential. We generated the full genome sequences of 200 EV-A71 strains sampled from various locations in Viet Nam between 2011 and 2013 and used these sequence data to determine the evolutionary history and phylodynamics of EV-A71 in Viet Nam, providing estimates of the effective reproduction number (Re) of the infection through time. In addition, we described the phylogeography of EV-A71 throughout Southeast Asia, documenting patterns of viral gene flow. Accordingly, our analysis reveals that a rapid genogroup switch from C4 to B5 likely took place during 2012 in Viet Nam. We show that the Re of subgenogroup C4 decreased during the time frame of sampling, whereas that of B5 increased and remained >1 at the end of 2013, corresponding to a rise in B5 prevalence. Our study reveals that the subgenogroup B5 virus that emerged into Viet Nam is closely related to variants that were responsible for large epidemics in Malaysia and Taiwan and therefore extends our knowledge regarding its associated area of endemicity. Subgenogroup B5 evidently has the potential to cause more widespread outbreaks across Southeast Asia. IMPORTANCE: EV-A71 is one of many viruses that cause HFMD, a common syndrome that largely affects infants and children. HFMD usually causes only mild illness with no long-term consequences. Occasionally, however, severe infection may arise, especially in very young children, causing neurological complications and even death. EV-A71 is highly contagious and is associated with the most severe HFMD cases, with large and frequent epidemics of the virus recorded worldwide. Although major advances have been made in the development of a potential EV-A71 vaccine, there is no current prevention and little is known about the patterns and dynamics of EV-A71 spread. In this study, we utilize full-length genome sequence data obtained from HFMD patients in Viet Nam, a geographical region where the disease has been endemic since 2003, to characterize the phylodynamics of this important emerging virus.
Assuntos
Enterovirus Humano A/genética , Genoma Viral/genética , Doença de Mão, Pé e Boca/epidemiologia , Doença de Mão, Pé e Boca/genética , Sequência de Bases , Criança , Surtos de Doenças , Enterovirus Humano A/classificação , Epidemias , Fluxo Gênico/genética , Doença de Mão, Pé e Boca/virologia , Humanos , Dados de Sequência Molecular , Filogeografia , Análise de Sequência de RNA , Vietnã/epidemiologia , Replicação Viral/fisiologiaRESUMO
Penicilliosis caused by Talaromyces marneffei is a common AIDS-defining illness in South and Southeast Asia. Diagnosis is based on culture which can take up to 14 days for identification, leading to treatment delay and increased mortality. We developed a TaqMan real-time PCR assay targeting the MP1 gene encoding an abundant cell wall protein specific to T. marneffei. The assay's performance was evaluated in MP1-containing plasmids, clinical isolates, and plasma from HIV-infected patients with and without penicilliosis. The assay consistently detected 10 copies of MP1-containing plasmids per reaction and 100 T. marneffei yeast cells per millilitre plasma. There were no amplification with seven other Penicillium species and six other HIV-associated fungal pathogens tested. The assay was evaluated in 70 patients with AIDS: 50 patients with culture-confirmed penicilliosis and 20 patients with opportunistic infections other than penicilliosis. The diagnostic sensitivity was 70.4% (19/27, 95% CI: 51.5-84.1%) and 52.2% (12/23, 95% CI: 33.0-70.8%) in plasma samples collected prior to and within 48 h of antifungal therapy respectively. The diagnostic specificity was 100% (20/20, 95% CI: 83.9-100%). This assay provides a useful tool for the rapid diagnosis of T. marneffei infection and has the potential to improve the management of patients with penicilliosis.
Assuntos
Proteínas Fúngicas/genética , Micoses/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Talaromyces/isolamento & purificação , Infecções Oportunistas Relacionadas com a AIDS/sangue , Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Antifúngicos/uso terapêutico , Sudeste Asiático , Proteínas Fúngicas/sangue , Infecções por HIV , Humanos , Micoses/sangue , Micoses/diagnóstico , Micoses/tratamento farmacológico , Talaromyces/classificação , Talaromyces/genéticaRESUMO
BACKGROUND: Hand foot and mouth disease (HFMD) is a disease of public health importance across the Asia-Pacific region. The disease is caused by enteroviruses (EVs), in particular enterovirus A71 (EV-A71). In EV-A71-associated HFMD, the infection is sometimes associated with severe manifestations including neurological involvement and fatal outcome. The availability of a robust diagnostic assay to distinguish EV-A71 from other EVs is important for patient management and outbreak response. METHODS: We developed and validated an internally controlled one-step single-tube real-time RT-PCR in terms of sensitivity, linearity, precision, and specificity for simultaneous detection of EVs and EV-A71. Subsequently, the assay was then applied on throat and rectal swabs sampled from 434 HFMD patients. RESULTS: The assay was evaluated using both plasmid DNA and viral RNA and has shown to be reproducible with a maximum assay variation of 4.41 % and sensitive with a limit of detection less than 10 copies of target template per reaction, while cross-reactivity with other EV serotypes was not observed. When compared against a published VP1 nested RT-PCR using 112 diagnostic throat and rectal swabs from 112 children with a clinical diagnosis of HFMD during 2014, the multiplex assay had a higher sensitivity and 100 % concordance with sequencing results which showed EVs in 77/112 (68.8 %) and EV-A71 in 7/112 (6.3 %). When applied to clinical diagnostics for 322 children, the assay detected EVs in throat swabs of 257/322 (79.8 %) of which EV-A71 was detected in 36/322 (11.2 %) children. The detection rate increased to 93.5 % (301/322) and 13.4 % (43/322) for EVs and EV-A71, respectively, when rectal swabs from 65 throat-negative children were further analyzed. CONCLUSION: We have successfully developed and validated a sensitive internally controlled multiplex assay for rapid detection of EVs and EV-A71, which is useful for clinical management and outbreak control of HFMD.
Assuntos
Infecções por Enterovirus/diagnóstico , Enterovirus/isolamento & purificação , Reação em Cadeia da Polimerase Multiplex/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Animais , Ásia , Criança , Pré-Escolar , Enterovirus/classificação , Enterovirus/genética , Feminino , Humanos , Lactente , Masculino , Reação em Cadeia da Polimerase Multiplex/normas , Faringe/virologia , Reação em Cadeia da Polimerase em Tempo Real/normas , Reto/virologia , Padrões de Referência , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas , Sensibilidade e EspecificidadeRESUMO
OBJECTIVES: We studied the immunogenicity after primary and booster vaccinations of Abdala COVID-19 vaccine, a receptor binding domain protein subunit vaccine, in Vietnamese people by determining the level of neutralization and cross-neutralization activities against the ancestral SARS-CoV-2 and its variants, and SARS-CoV-1. METHODS: We performed a prospective observational study, enrolling adults aged 19-59 years in Dong Thap province, southern Vietnam, and collected blood samples from baseline until 4 weeks post booster dose. We measured anti-nucleocapsid, anti-spike and neutralizing antibodies against SARS-CoV-2, and assessed the cross-neutralization against 14 SARS-CoV-2 variants, and SARS-CoV-1. Complementary antibody data came from Vietnamese healthcare workers fully vaccinated with ChAdOx1-S. RESULTS: After primary vaccination, anti-spike antibody and neutralizing antibodies were detectable in 98.4% and 87% of 251 study participants, respectively, with neutralizing antibody titers similar to that induced by ChAdOx1-S vaccine. Antibody responses after a homologous (Abdala COVID-19) or heterologous (mRNA BNT162b2) booster could neutralize 14 SARS-CoV-2 variants (including Omicron), and SARS-CoV-1. CONCLUSIONS: Abdala COVID-19 vaccine is immunogenic in Vietnamese people. Enhanced antibody response after a booster dose could cross-neutralize 14 SARS-CoV-2 variants and SARS-CoV-1. Our results have added to the growing body of knowledge about the contribution of protein subunit vaccine platforms to pandemic control.