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1.
Clin Infect Dis ; 58(4): e106-9, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24248810

RESUMO

To investigate the nasal carriage of some respiratory bacterial pathogens that are responsible for infections associated with person-to-person transmission, we conducted a cohort survey of pilgrims departing to Mecca for the 2012 Hajj season. In this report, we demonstrate the acquisition of Streptococcus pneumoniae nasal carriage in returning Hajj pilgrims.


Assuntos
Portador Sadio/epidemiologia , Aglomeração , Infecções Pneumocócicas/epidemiologia , Streptococcus pneumoniae/isolamento & purificação , Viagem , Portador Sadio/microbiologia , Estudos de Coortes , Humanos , Estudos Longitudinais , Mucosa Nasal/microbiologia , Infecções Pneumocócicas/microbiologia , Estudos Prospectivos , Arábia Saudita/epidemiologia
2.
Emerg Infect Dis ; 20(11): 1821-7, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25341199

RESUMO

Pilgrims returning from the Hajj might contribute to international spreading of respiratory pathogens. Nasal and throat swab specimens were obtained from 129 pilgrims in 2013 before they departed from France and before they left Saudi Arabia, and tested by PCR for respiratory viruses and bacteria. Overall, 21.5% and 38.8% of pre-Hajj and post-Hajj specimens, respectively, were positive for ≥1 virus (p = 0.003). One third (29.8%) of the participants acquired ≥1 virus, particularly rhinovirus (14.0%), coronavirus E229 (12.4%), and influenza A(H3N2) virus (6.2%) while in Saudi Arabia. None of the participants were positive for the Middle East respiratory syndrome coronavirus. In addition, 50.0% and 62.0% of pre-Hajj and post-Hajj specimens, respectively, were positive for Streptococcus pneumoniae (p = 0.053). One third (36.3%) of the participants had acquired S. pneumoniae during their stay. Our results confirm high acquisition rates of rhinovirus and S. pneumoniae in pilgrims and highlight the acquisition of coronavirus E229.


Assuntos
Infecções Respiratórias/microbiologia , Infecções Respiratórias/virologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Bactérias/classificação , Bactérias/isolamento & purificação , Estudos de Coortes , Feminino , França/epidemiologia , História do Século XXI , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Vigilância em Saúde Pública , Religião , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/história , Arábia Saudita/epidemiologia , Inquéritos e Questionários , Viagem , Vírus/classificação , Vírus/isolamento & purificação
3.
J Med Virol ; 86(4): 585-91, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24105757

RESUMO

The 2011-2012 and 2012-2013 post-pandemic influenza outbreaks were characterized by variability in the A(H3N2) influenza viruses, resulting in low to moderate vaccine effectiveness (VE). The aim of this study was to investigate the molecular evolution and vaccine strain match of the A(H3N2) influenza viruses, having been circulated throughout the population of the French Corsica Island in 2011-2012 and again in 2012-2013. Clinical samples from 31 patients with confirmed A(H3N2) influenza viruses were collected by general practitioners (GPs) over these two consecutive seasons. An analysis of genetic distance and antigenic drift was conducted. Based on a hemagglutinin (HA) aminoacid sequence analysis, the Corsican A(H3N2) viruses fell into the A/Victoria/208/2009 genetic clade, group 3. All influenza viruses were characterized by at least four fixed amino acid mutations which were: N145S (epitope A); Q156H and V186G (epitope B) Y219S (epitope D), with respect to the A/Perth/16/2009 (reference vaccine strain for the 2011-2012) and the A/Victoria/361/2011 (reference vaccine strain for the 2012-2013). Using the p(epitope) model, the percentages of the perfect match VE estimated against circulated strains declined within and between seasons, with estimations of <50%. Overall, these results seem to indicate an antigenic drift of the A(H3N2) influenza viruses which were circulated in Corsica. These findings highlight the importance of the continuous and careful surveillance of genetic changes in the HA domain during seasonal influenza epidemics, in order to provide information on newly emerging genetic variants.


Assuntos
Variação Antigênica/genética , Deriva Genética , Hemaglutininas Virais/genética , Vírus da Influenza A Subtipo H3N2/genética , Influenza Humana/epidemiologia , Adolescente , Adulto , Sequência de Aminoácidos , Substituição de Aminoácidos/genética , Sequência de Bases , Criança , Pré-Escolar , Surtos de Doenças , Feminino , França/epidemiologia , Humanos , Vacinas contra Influenza , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mutação , Estações do Ano , Análise de Sequência de DNA , Adulto Jovem
4.
Virol J ; 11: 13, 2014 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-24468218

RESUMO

BACKGROUND: Following the 2009 swine flu pandemic, a cohort for pandemic influenza (CoPanFlu) study was established in Djibouti, the Horn of Africa, to investigate its case prevalence and risk predictors' at household level. METHODS: From the four city administrative districts, 1,045 subjects from 324 households were included during a face-to-face encounter between 11th November 2010 and 15th February 2011. Socio-demographic details were collected and blood samples were analysed in haemagglutination inhibition (HI) assays. Risk assessments were performed in a generalised estimating equation model. RESULTS: In this study, the indicator of positive infection status was set at an HI titre of ≥ 80, which was a relevant surrogate to the seroconversion criterion. All positive cases were considered to be either recent infections or past contact with an antigenically closely related virus in humans older than 65 years. An overall sero-prevalence of 29.1% and a geometrical mean titre (GMT) of 39.5% among the residents was observed. Youths, ≤ 25 years and the elderly, ≥65 years had the highest titres, with values of 35.9% and 29.5%, respectively. Significantly, risk was high amongst youths ≤ 25 years, (OR 1.5-2.2), residents of District 4(OR 2.9), students (OR 1.4) and individuals living near to river banks (OR 2.5). Belonging to a large household (OR 0.6), being employed (OR 0.5) and working in open space-outdoor (OR 0.4) were significantly protective. Only 1.4% of the cohort had vaccination against the pandemic virus and none were immunised against seasonal influenza. CONCLUSION: Despite the limited number of incident cases detected by the surveillance system, A(H1N1)pdm09 virus circulated broadly in Djibouti in 2010 and 2011. Age-group distribution of cases was similar to what has been reported elsewhere, with youths at the greatest risk of infection. Future respiratory infection control should therefore be tailored to reach specific and vulnerable individuals such as students and those working in groups indoors. It is concluded that the lack of robust data provided by surveillance systems in southern countries could be responsible for the underestimation of the epidemiological burden, although the main characteristics are essentially similar to what has been observed in developed countries.


Assuntos
Características da Família , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/epidemiologia , Influenza Humana/virologia , Pandemias , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Antivirais/sangue , Criança , Pré-Escolar , Estudos Transversais , Djibuti/epidemiologia , Feminino , Testes de Inibição da Hemaglutinação , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Adulto Jovem
5.
Clin Infect Dis ; 57(7): 992-1000, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23839997

RESUMO

BACKGROUND: The Hajj is the oldest and largest annual mass gathering in the world and may increase the risk of spread of respiratory viruses. METHODS: We performed a prospective survey among a cohort of pilgrims departing from Marseille, France, to Mecca in the Kingdom of Saudi Arabia (KSA) for the 2012 Hajj season. Nasal swabs were collected from participants and tested for 11 respiratory viruses by real-time reverse transcription polymerase chain reaction. RESULTS: Of 165 participants sampled before departing to the KSA, 8 (4.8%) were positive for at least 1 virus (5 rhinovirus, 1 influenza C, 1 adenovirus, and 1 enterovirus). Seventy symptomatic pilgrims underwent additional nasal swabs during their pilgrimage in the KSA, of which 27 (38.6%) were positive for at least 1 virus (19 rhinovirus, 6 influenza A, 1 influenza C, 1 respiratory syncytial virus B, 1 metapneumovirus, 1 adenovirus, and 1 enterovirus). This was significantly higher than the 4.8% who were positive before departing for the KSA (P < .001). Of 154 pilgrims sampled before leaving the KSA, 17 (11%) were positive for at least 1 virus (13 rhinovirus, 3 adenovirus, 2 influenza B, and 1 enterovirus), which was also significantly higher than the percentage of positive pilgrims (4.8%), before departing for the KSA (P = .040). CONCLUSIONS: This study suggests a rapid acquisition of respiratory viruses among pilgrims during their stay in the KSA, most notably rhinovirus, and highlights the potential of spreading these infections in the pilgrims' home countries upon their return.


Assuntos
Islamismo , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Viagem/estatística & dados numéricos , Vírus/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cavidade Nasal/virologia , Infecções Respiratórias/transmissão , Arábia Saudita/epidemiologia , Inquéritos e Questionários , Vírus/classificação
6.
Emerg Infect Dis ; 19(1): 102-5, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23260031

RESUMO

Five persons in France were infected with Orf virus after skin wounds were exposed to infected sheep tissues during Eid al-Adha, the Muslim Feast of Sacrifice. Infections were confirmed by electron microscopy, PCR, and sequence analysis. Prevention and control of this underdiagnosed disease can be achieved by educating physicians, slaughterhouse workers, and persons participating in Eid al-Adha.


Assuntos
Ectima Contagioso/epidemiologia , Ectima Contagioso/transmissão , Islamismo , Vírus do Orf/fisiologia , Adulto , Animais , Ectima Contagioso/diagnóstico , Ectima Contagioso/virologia , Feminino , França/epidemiologia , Férias e Feriados , Humanos , Masculino , Pessoa de Meia-Idade , Vírus do Orf/patogenicidade , Carneiro Doméstico
7.
BMC Public Health ; 12: 417, 2012 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-22676272

RESUMO

BACKGROUND: The risk of influenza infection depends on biological characteristics, individual or collective behaviors and the environmental context. The Cohorts for Pandemic Influenza (CoPanFlu) France study was set up in 2009 after the identification of the novel swine-origin A/H1N1 pandemic influenza virus. This cohort of 601 households (1450 subjects) representative for the general population aims at using an integrative approach to study the risk and characteristics of influenza infection as a complex combination of data collected from questionnaires regarding sociodemographic, medical, behavioral characteristics of subjects and indoor environment, using biological samples or environmental databases. METHODS/DESIGN: Households were included between December 2009 and July 2010. The design of this study relies on systematic follow-up visits between influenza seasons and additional visits during influenza seasons, when an influenza-like illness is detected in a household via an active surveillance system. During systematic visits, a nurse collects individual and environmental data on questionnaires and obtains blood samples from all members of the household. When an influenza-like-illness is detected, a nurse visits the household three times during the 12 following days, and collects data on questionnaires regarding exposure and symptoms, and biological samples (including nasal swabs) from all subjects in the household. The end of the follow-up period is expected in fall 2012. DISCUSSION: The large amount of data collected throughout the follow-up will permit a multidisciplinary study of influenza infections. Additional data is being collected and analyzed in this ongoing cohort. The longitudinal analysis of these households will permit integrative analyses of complex phenomena such as individual, collective and environmental risk factors of infection, routes of transmission, or determinants of the immune response to infection or vaccination.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Influenza Humana/epidemiologia , Pandemias , Vigilância da População/métodos , Estudos de Coortes , Características da Família , França/epidemiologia , Humanos , Projetos de Pesquisa , Fatores de Risco
9.
J Gen Virol ; 91(Pt 5): 1275-83, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20089800

RESUMO

Sandflies are widely distributed around the Mediterranean Basin. Therefore, human populations in this area are potentially exposed to sandfly-transmitted diseases, including those caused by phleboviruses. Whilst there are substantial data in countries located in the northern part of the Mediterranean basin, few data are available for North Africa. In this study, a total of 1489 sandflies were collected in 2008 in Tunisia from two sites, bioclimatically distinct, located 235 km apart, and identified morphologically. Sandfly species comprised Phlebotomus perniciosus (52.2%), Phlebotomus longicuspis (30.1%), Phlebotomus papatasi (12.0%), Phlebotomus perfiliewi (4.6%), Phlebotomus langeroni (0.4%) and Sergentomyia minuta (0.5%). PCR screening, using generic primers for the genus Phlebovirus, resulted in the detection of ten positive pools. Sequence analysis revealed that two pools contained viral RNA corresponding to a novel virus closely related to sandfly fever Naples virus. Virus isolation in Vero cells was achieved from one pool. Genetic and phylogenetic characterization based on sequences in the three genomic segments showed that it was a novel virus distinct from other recognized members of the species. This novel virus was provisionally named Punique virus. Viral sequences in the polymerase gene corresponding to another phlebovirus closely related to but distinct from sandfly fever Sicilian virus were obtained from the eight remaining positive pools.


Assuntos
Phlebovirus/classificação , Phlebovirus/isolamento & purificação , Psychodidae/virologia , RNA Viral/genética , Animais , Chlorocebus aethiops , Análise por Conglomerados , Dados de Sequência Molecular , Phlebovirus/genética , Filogenia , RNA Polimerase Dependente de RNA/genética , Vírus da Febre do Flebótomo Napolitano/genética , Análise de Sequência de DNA , Homologia de Sequência , Tunísia , Células Vero , Proteínas Virais/genética
10.
Emerg Infect Dis ; 15(5): 781-4, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19402968

RESUMO

In early 2009, four human cases of cowpox virus cutaneous infection in northern France, resulting from direct contact with infected pet rats (Rattus norvegicus), were studied. Pet rats, originating from the same pet store, were shown to be infected by a unique virus strain. Infection was then transmitted to humans who purchased or had contact with pet rats.


Assuntos
Animais Domésticos/virologia , Vírus da Varíola Bovina/isolamento & purificação , Varíola Bovina/transmissão , Surtos de Doenças , Ratos/virologia , Adolescente , Adulto , Animais , Varíola Bovina/epidemiologia , Varíola Bovina/veterinária , Varíola Bovina/virologia , Vírus da Varíola Bovina/genética , Vírus da Varíola Bovina/patogenicidade , Feminino , França/epidemiologia , Humanos , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Doenças dos Roedores/epidemiologia , Doenças dos Roedores/virologia , Análise de Sequência de DNA , Zoonoses
12.
Artigo em Inglês | MEDLINE | ID: mdl-30533609

RESUMO

Three variants of the multidrug-resistant plasmid pLUH01 were assembled by deep sequencing from nasopharyngeal swabs. All have a 21-bp deletion in the RS14515 hypothetical gene. Variants 1 through 3 have 2, 6, and 3 nucleotide substitutions, respectively, compared to the pLUH01 reference genome. We named the new plasmid variants pLUH01/Lancaster/2015/1 to pLUH01/Lancaster/2015/3.

13.
Sci Rep ; 7(1): 2728, 2017 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-28578421

RESUMO

Infections of the central nervous system (CNS) are severe conditions, leading to neurological sequelae or death. Knowledge of the causative agents is essential to develop guidelines for case management in resource-limited settings. Between August 2009 and October 2012, we conducted a prospective descriptive study of the aetiology of suspected CNS infections in children two months to 12 years old, with fever and at least one sign of CNS involvement in Mbarara Hospital, Uganda. Children were clinically evaluated on admission and discharge, and followed-up for 6 months for neurological sequelae. Pathogens were identified from cerebrospinal fluid (CSF) and blood using microbiological and molecular methods. We enrolled 459 children. Plasmodium falciparum (36.2%) and bacteria in CSF (13.3%) or blood (3.3%) were the most detected pathogens. Viruses were found in 27 (5.9%) children. No pathogen was isolated in 207 (45.1%) children. Patterns varied by age and HIV status. Eighty-three (18.1%) children died during hospitalisation, and 23 (5.0%) during follow-up. Forty-one (13.5%) children had neurological sequelae at the last visit. While malaria remains the main aetiology in children with suspected CNS infections, no pathogen was isolated in many children. The high mortality and high rate of neurological sequelae highlight the need for efficient diagnosis.


Assuntos
Infecções do Sistema Nervoso Central/epidemiologia , Infecções do Sistema Nervoso Central/etiologia , Infecções do Sistema Nervoso Central/diagnóstico , Infecções do Sistema Nervoso Central/terapia , Criança , Pré-Escolar , Comorbidade , Gerenciamento Clínico , Feminino , Seguimentos , Humanos , Lactente , Masculino , Razão de Chances , Avaliação de Resultados em Cuidados de Saúde , Uganda/epidemiologia
14.
Genome Announc ; 5(31)2017 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-28774975

RESUMO

The genome sequence of human papillomavirus type 20 (HPV-20; family Papillomaviridae, genus Betapapillomavirus, species Betapapillomavirus 1, type 20) was assembled by deep sequencing from nasopharyngeal swabs. The assembled genome is 0.37% divergent over its full length from the single complete genome of HPV-20 in GenBank (U31778). We named the strain HPV-20/Lancaster/2015.

15.
Genome Announc ; 5(20)2017 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-28522701

RESUMO

The genome of human papillomavirus type 23 (HPV-23; family Papillomaviridae, genus Betapapillomavirus, species Betapapillomavirus 2, type 23) was assembled by deep sequencing from nasopharyngeal swabs. The assembled genome is 2.7% divergent over its full length from the single complete genome of HPV-23 in GenBank (accession no. U31781). We named the strain HPV-23/Lancaster/2015.

16.
Sci Data ; 4: 170161, 2017 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-29064471

RESUMO

Nasopharyngeal swabs were taken from volunteers attending a general medical practice and a general hospital in Lancaster, UK, and at Lancaster University, in the winter of 2014-2015. 51 swabs were selected based on high RNA yield and allocated to deep sequencing pools as follows: patients with chronic obstructive pulmonary disease; asthmatics; adults with no respiratory symptoms; adults with feverish respiratory symptoms; adults with respiratory symptoms and presence of antibodies against influenza C; paediatric patients with respiratory symptoms (2 pools); adults with influenza C infection (2 pools), giving a total of 9 pools. Illumina sequencing was performed, with data yields per pool in the range of 345.6 megabases to 14 gigabases after removal of reads aligning to the human genome. The data were deposited in the Sequence Read Archive at NCBI, and constitute a resource for study of the viral, bacterial and fungal metagenome of the human nasopharynx in healthy and diseased states and comparison with other metagenomic studies on the human respiratory tract.


Assuntos
Metagenômica , Nasofaringe , Sequenciamento de Nucleotídeos em Larga Escala , Humanos
17.
Genome Announc ; 5(12)2017 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-28336607

RESUMO

The genome of human rhinovirus A22 (HRV-A22) was assembled by deep sequencing RNA samples from nasopharyngeal swabs. The assembled genome is 8.7% divergent from the HRV-A22 reference strain over its full length, and it is only the second full-length genome sequence for HRV-A22. The new strain is designated strain HRV-A22/Lancaster/2015.

18.
Sci Rep ; 7: 46578, 2017 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-28406194

RESUMO

Influenza C is not included in the annual seasonal influenza vaccine, and has historically been regarded as a minor respiratory pathogen. However, recent work has highlighted its potential role as a cause of pneumonia in infants. We performed nasopharyngeal or nasal swabbing and/or serum sampling (n = 148) in Lancaster, UK, over the winter of 2014-2015. Using enzyme-linked immunosorbent assay (ELISA), we obtain seropositivity of 77%. By contrast, only 2 individuals, both asymptomatic adults, were influenza C-positive by polymerase chain reaction (PCR). Deep sequencing of nasopharyngeal samples produced partial sequences for 4 genome segments in one of these patients. Bayesian phylogenetic analysis demonstrated that the influenza C genome from this individual is evolutionarily distant to those sampled in recent years and represents a novel genome constellation, indicating that it may be a product of a decades-old reassortment event. Although we find no evidence that influenza C was a significant respiratory pathogen during the winter of 2014-2015 in Lancaster, we confirm previous observations of seropositivity in the majority of the population. (170 words).


Assuntos
Gammainfluenzavirus , Influenza Humana , Filogenia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Influenza Humana/epidemiologia , Influenza Humana/genética , Influenza Humana/imunologia , Gammainfluenzavirus/genética , Gammainfluenzavirus/imunologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Reino Unido/epidemiologia
19.
PLoS Negl Trop Dis ; 10(12): e0004840, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27977670

RESUMO

A cross sectional serological survey of arboviral infections in humans was conducted on the three islands of the Union of Comoros, Indian Ocean, in order to test a previously suggested contrasted exposure of the three neighboring islands to arthropod-borne epidemics. Four hundred human sera were collected on Ngazidja (Grande Comore), Mwali (Mohéli) and Ndzouani (Anjouan), and were tested by ELISA for IgM and/or IgG antibodies to Dengue (DENV), Chikungunya (CHIKV), Rift Valley fever (RVFV), West Nile (WNV), Tick borne encephalitis (TBEV) and Yellow fever (YFV) viruses and for neutralizing antibodies to DENV serotypes 1-4. Very few sera were positive for IgM antibodies to the tested viruses indicating that the sero-survey was performed during an inter epidemic phase for the investigated arbovirus infections, except for RVF which showed evidence of recent infections on all three islands. IgG reactivity with at least one arbovirus was observed in almost 85% of tested sera, with seropositivity rates increasing with age, indicative of an intense and long lasting exposure of the Comorian population to arboviral risk. Interestingly, the positivity rates for IgG antibodies to DENV and CHIKV were significantly higher on Ngazidja, confirming the previously suggested prominent exposure of this island to these arboviruses, while serological traces of WNV infection were detected most frequently on Mwali suggesting some transmission specificities associated with this island only. The study provides the first evidence for circulation of RVFV in human populations from the Union of Comoros and further suggests that the virus is currently circulating on the three islands in an inconspicuous manner. This study supports contrasted exposure of the islands of the Comoros archipelago to arboviral infections. The observation is discussed in terms of ecological factors that may affect the abundance and distribution of vector populations on the three islands as well as concurring anthropogenic factors that may impact arbovirus transmission in this diverse island ecosystem.


Assuntos
Infecções por Arbovirus/epidemiologia , Adolescente , Adulto , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Infecções por Arbovirus/transmissão , Infecções por Arbovirus/virologia , Arbovírus/imunologia , Febre de Chikungunya/epidemiologia , Febre de Chikungunya/imunologia , Febre de Chikungunya/transmissão , Febre de Chikungunya/virologia , Comores/epidemiologia , Estudos Transversais , Dengue/epidemiologia , Dengue/imunologia , Dengue/transmissão , Dengue/virologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Mosquitos Vetores/virologia , Febre do Vale de Rift/epidemiologia , Febre do Vale de Rift/imunologia , Febre do Vale de Rift/transmissão , Febre do Vale de Rift/virologia , Estudos Soroepidemiológicos , Sorogrupo , Febre Amarela/epidemiologia , Febre Amarela/imunologia , Febre Amarela/transmissão , Febre Amarela/virologia , Adulto Jovem
20.
Vaccine ; 33(49): 7015-21, 2015 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-26387434

RESUMO

INTRODUCTION: Haemagglutination-inhibition (HI) antibody titer is a correlate of protection against influenza; its persistence after infection or vaccination is important to determining susceptibility to subsequent infection. Few studies, however, have reported longitudinal data regarding the magnitude and duration of HI protection following natural seasonal influenza A infection. METHODS: Using French influenza cohort study data collected from 2008 to 2010, we investigated persistence of serological protection among subjects according to influenza-like illness (ILI) and laboratory-confirmed seasonal 2007 influenza A(H1N1) infection status at inclusion in 2008 (ILI-A(H1N1) positive, ILI-A(H1N1) negative, or no-ILI). Antibody titers against seasonal 2007 A(H1N1) were determined using the HI technique for sera. Regression models for interval-censored data were used to estimate geometric mean titers (GMT) for HI assays. A logistic regression model adjusted for age group (subjects <30, 30-50 and >50 years old) was used to quantify the association between HI titer and protection against infection. RESULTS: Based on 310 total subjects, influenza A(H1N1) infection was confirmed in 39 of 115 ILI subjects at inclusion. GMT associated with 50% probability of protection among ILI subjects decreased with age group (subjects <30 yo: GMT of 40.8 was associated with 50% [95CI: 29.3%; 70.7%] probability of protection, subjects 30-50 yo: 26.8 [95CI: 34.4%; 65.6%] and subjects >50 yo: 8.9 [95CI: 15.3%; 84.7%]). GMT declined after the first annual study visit among ILI-A(H1N1) positive subjects but remained higher compared to inclusion at the 2010 study visit (41.5 [95CI: 34.8; 49.5], p=0.0157). GMT remained stable among ILI-A(H1N1) negative subjects (p=0.7502), but decreased among no-ILI subjects (p<0.0001). CONCLUSION: Our results confirm the positive relationship between HI titer and probability of protection among naturally infected subjects, and provides evidence that protection associated with HI titer varies with age. This longitudinal analysis suggests the rise in HI titers following seasonal 2007 influenza A(H1N1) infection may persist into subsequent influenza seasons.


Assuntos
Anticorpos Antivirais/sangue , Proteção Cruzada , Vírus da Influenza A Subtipo H1N1 , Influenza Humana/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , França , Testes de Inibição da Hemaglutinação , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
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