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1.
Recurso na Internet em Inglês, Espanhol, Português | LIS - Localizador de Informação em Saúde | ID: lis-LISBR1.1-47094

RESUMO

À medida que a pandemia de COVID-19 continua evoluindo, muitas pessoas costumam comparar a enfermidade causada pelo novo coronavírus com a gripe. Ambas causam doenças respiratórias, mas existem diferenças importantes entre os dois vírus e a forma como eles se propagam. Isso tem implicações importantes para as medidas de saúde pública que devem ser implementadas para responder a cada um dos patógenos


Assuntos
Betacoronavirus , Influenza Humana/transmissão , Infecções por Coronavirus/transmissão
2.
Euro Surveill ; 25(4)2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-32019669

RESUMO

Since December 2019, China has been experiencing a large outbreak of a novel coronavirus (2019-nCoV) which can cause respiratory disease and severe pneumonia. We estimated the basic reproduction number R0 of 2019-nCoV to be around 2.2 (90% high density interval: 1.4-3.8), indicating the potential for sustained human-to-human transmission. Transmission characteristics appear to be of similar magnitude to severe acute respiratory syndrome-related coronavirus (SARS-CoV) and pandemic influenza, indicating a risk of global spread.


Assuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/transmissão , Surtos de Doenças/estatística & dados numéricos , Pneumonia Viral/transmissão , Síndrome Respiratória Aguda Grave/transmissão , Replicação Viral , China/epidemiologia , Infecções por Coronavirus/epidemiologia , Saúde Global , Humanos , Controle de Infecções , Vírus da Influenza A/patogenicidade , Influenza Humana/transmissão , Pandemias , Pneumonia Viral/epidemiologia , Risco , Vírus da SARS/patogenicidade
3.
Sports Health ; 12(1): 51-57, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31660785

RESUMO

BACKGROUND: Athletic training rooms have a high prevalence of bacteria, including multidrug-resistant organisms, increasing the risk for both local and systematic infections in athletes. There are limited data outlining formal protocols or standardized programs to reduce bacterial and viral burden in training rooms as a means of decreasing infection rate at the collegiate and high school levels. HYPOTHESIS: Adaptation of a hygiene protocol would lead to a reduction in bacterial and viral pathogen counts in athletic training rooms. STUDY DESIGN: Cohort study. LEVEL OF EVIDENCE: Level 3. METHODS: Two high school and 2 collegiate athletic training rooms were studied over the course of the 2017-2018 academic year. A 3-phase protocol, including introduction of disinfectant products followed by student-athlete and athletic trainer education, was implemented at the 4 schools. Multiple surfaces in the athletic training rooms were swabbed at 4 time points throughout the investigation. Bacterial and viral burden from swabs were analyzed for overall bacterial aerobic plate count (APC), bacterial adenosine triphosphate activity, influenza viral load, and multidrug-resistant organisms such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE). RESULTS: Overall bacterial load, as measured by APC, was reduced by 94.7% (95% CI, 72.6-99.0; P = 0.003) over the course of the investigation after protocol implementation. MRSA and VRE were found on 24% of surfaces prior to intervention and were reduced to 0% by the end of the study. Influenza was initially detected on 25% of surfaces, with no detection after intervention. No cases of athletic training room-acquired infections were reported during the study period. CONCLUSION: A uniform infection control protocol was effective in reducing bacterial and viral burden, including multidrug-resistant organisms, when implemented in the athletic training rooms of 2 high schools and 2 colleges. CLINICAL RELEVANCE: A standardized infection control protocol can be utilized in athletic training rooms to reduce bacterial and viral burden.


Assuntos
Infecções Comunitárias Adquiridas/prevenção & controle , Reservatórios de Doenças/microbiologia , Controle de Infecções/métodos , Instituições Acadêmicas , Infecções Comunitárias Adquiridas/transmissão , Desinfetantes/administração & dosagem , Infecções por Bactérias Gram-Positivas/prevenção & controle , Infecções por Bactérias Gram-Positivas/transmissão , Desinfecção das Mãos , Educação em Saúde , Humanos , Influenza Humana/prevenção & controle , Influenza Humana/transmissão , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Orthomyxoviridae/isolamento & purificação , Comportamento de Redução do Risco , Infecções Estafilocócicas/prevenção & controle , Infecções Estafilocócicas/transmissão , Enterococos Resistentes à Vancomicina/isolamento & purificação
4.
Sci Total Environ ; 701: 134607, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31710904

RESUMO

Most previous studies focused on the association between climate variables and seasonal influenza activity in tropical or temperate zones, little is known about the associations in different influenza types in subtropical China. The study aimed to explore the associations of multiple climate variables with influenza A (Flu-A) and B virus (Flu-B) transmissions in Shanghai, China. Weekly influenza virus and climate data (mean temperature (MeanT), diurnal temperature range (DTR), relative humidity (RH) and wind velocity (Wv)) were collected between June 2012 and December 2018. Generalized linear models (GLMs), distributed lag non-linear models (DLNMs) and regression tree models were developed to assess such associations. MeanT exerted the peaking risk of Flu-A at 1.4 °C (2-weeks' cumulative relative risk (RR): 14.88, 95% confidence interval (CI): 8.67-23.31) and 25.8 °C (RR: 12.21, 95%CI: 6.64-19.83), Flu-B had the peak at 1.4 °C (RR: 26.44, 95%CI: 11.52-51.86). The highest RR of Flu-A was 23.05 (95%CI: 5.12-88.45) at DTR of 15.8 °C, that of Flu-B was 38.25 (95%CI: 15.82-87.61) at 3.2 °C. RH of 51.5% had the highest RR of Flu-A (9.98, 95%CI: 4.03-26.28) and Flu-B (4.63, 95%CI: 1.95-11.27). Wv of 3.5 m/s exerted the peaking RR of Flu-A (7.48, 95%CI: 2.73-30.04) and Flu-B (7.87, 95%CI: 5.53-11.91). DTR ≥ 12 °C and MeanT <22 °C were the key drivers for Flu-A and Flu-B, separately. The study found complex non-linear relationships between climate variability and different influenza types in Shanghai. We suggest the careful use of meteorological variables in influenza prediction in subtropical regions, considering such complex associations, which may facilitate government and health authorities to better minimize the impacts of seasonal influenza.


Assuntos
Clima , Exposição Ambiental/estatística & dados numéricos , Influenza Humana/epidemiologia , China/epidemiologia , Humanos , Umidade , Influenza Humana/transmissão
5.
J Environ Public Health ; 2019: 6741202, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31871470

RESUMO

The external environment directly influences human health. However, what happens inside? This work deals with the effect that the interior thermal variables have on the propagation of respiratory diseases and focused on the relation of the temperature and relative humidity inside social housing in the 1040 parishes of Ecuador and the transmission of influenza. On the one hand, historical weather-related variables were used to simulate and estimate the interior conditions, and thresholds on temperature and humidity were determined. On the other hand, the health-related variable was determined by analyzing the statistics corresponding to the influenza and viral pneumonia in 2009 since that year was critical for these diseases; the data were divided by month for each parish. Finally, the correlation of these variables determines the relative importance of the interior conditions on the respiratory health of its inhabitants. The preliminary results indicate that the places with the lowest temperatures and relative humidity could favor the virus transmission. Also, the analysis indicated that respiratory diseases increase in August and October. In this way, it is clear that social housing projects in Ecuador require a study which guarantees not only energy efficiency and sustainability related issues but also the well-being of their inhabitants.


Assuntos
Habitação/estatística & dados numéricos , Influenza Humana/epidemiologia , Equador/epidemiologia , Humanos , Umidade , Influenza Humana/transmissão , Morbidade , Pneumonia Viral/epidemiologia , Pneumonia Viral/transmissão , Estações do Ano , Análise Espaço-Temporal , Temperatura Ambiente
6.
PLoS Comput Biol ; 15(12): e1007589, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31877122

RESUMO

Households are important settings for the transmission of seasonal influenza. Previous studies found that the per-person risk of within-household transmission decreases with household size. However, more detailed heterogeneities driven by household composition and contact patterns have not been studied. We employed a mathematical model that accounts for infections both from outside and within the household. The model was applied to citywide primary school seasonal influenza surveillance and household surveys from 10,486 students during the 2014/15 season in Matsumoto city, Japan. We compared a range of models to estimate the structure of household transmission and found that familial relationship and household composition strongly influenced the transmission patterns of seasonal influenza in households. Children had a substantially high risk of infection from outside the household (up to 20%) compared with adults (1-3%). Intense transmission was observed within-generation (between children/parents/grandparents) and also between mother and child, with transmission risks typically ranging from 5-20% depending on the transmission route and household composition. Children were identified as the largest source of secondary transmission, with family structure influencing infection risk.


Assuntos
Características da Família , Influenza Humana/transmissão , Adulto , Criança , Cidades , Biologia Computacional , Suscetibilidade a Doenças/epidemiologia , Feminino , Humanos , Influenza Humana/epidemiologia , Japão/epidemiologia , Masculino , Modelos Biológicos , Modelos Estatísticos , Fatores de Risco , Instituições Acadêmicas , Estações do Ano , Estudantes/estatística & dados numéricos , Inquéritos e Questionários
8.
PLoS Comput Biol ; 15(10): e1007096, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31658250

RESUMO

Seasonal influenza poses serious problems for global public health, being a significant contributor to morbidity and mortality. In England, there has been a long-standing national vaccination programme, with vaccination of at-risk groups and children offering partial protection against infection. Transmission models have been a fundamental component of analysis, informing the efficient use of limited resources. However, these models generally treat each season and each strain circulating within that season in isolation. Here, we amalgamate multiple data sources to calibrate a susceptible-latent-infected-recovered type transmission model for seasonal influenza, incorporating the four main strains and mechanisms linking prior season epidemiological outcomes to immunity at the beginning of the following season. Data pertaining to nine influenza seasons, starting with the 2009/10 season, informed our estimates for epidemiological processes, virological sample positivity, vaccine uptake and efficacy attributes, and general practitioner influenza-like-illness consultations as reported by the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC). We performed parameter inference via approximate Bayesian computation to assess strain transmissibility, dependence of present season influenza immunity on prior protection, and variability in the influenza case ascertainment across seasons. This produced reasonable agreement between model and data on the annual strain composition. Parameter fits indicated that the propagation of immunity from one season to the next is weaker if vaccine derived, compared to natural immunity from infection. Projecting the dynamics forward in time suggests that while historic immunity plays an important role in determining annual strain composition, the variability in vaccine efficacy hampers our ability to make long-term predictions.


Assuntos
Influenza Humana/epidemiologia , Influenza Humana/transmissão , Modelos Teóricos , Vacinação/tendências , Teorema de Bayes , Inglaterra/epidemiologia , Humanos , Vacinas contra Influenza/imunologia , Prática de Saúde Pública , Estações do Ano
9.
Food Environ Virol ; 11(4): 427-439, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31549297

RESUMO

The 2017-2018 flu season is considered to be one of the most severe, with numerous influenza outbreaks worldwide. In an infectious disease hospital of Qinhuangdao, air samples were collected daily from outpatient hall, clinical laboratory, fever clinic, children's ward (Children's Ward I/Children's Ward II), and adult ward during 23-29 January 2018 (peak flu activity) and 9-15 April 2018 (low flu activity). The air samples were collected with SLC-SiOH magnetic beads using impingement samplers. Real-time PCR assay was used to detect the RNA of airborne influenza (IFVA and IFVB) in the 91 collected aerosol samples. The results indicated that the air samples collected from the children's wards, adult ward and fever clinic were detected with airborne influenza viruses. However, the samples collected from outpatient hall and clinical laboratory were absence of influenza viruses. In addition, the subtypes of pH1N1/IFVA, H3N2/IFVA, yamagata/IFVB, and victoria/IFVB were detected among the samples with positive IFVA and IFVB. Notably, a new developed subtype of pH1N1 (an epidemic in 2018) was detected in the aerosol samples. In summary, this study profiled the distribution of airborne influenza in an infectious hospital in Qinhuangdao during 2017-2018 flu season. Patients infected with influenza could release airborne particles containing the virus into their environment. Healthcare workers and visitors in those places might have frequent exposure to airborne influenza virus. Therefore, we recommend some protective measures such as air disinfection and mask wearing to prevent and control the transmission of airborne influenza in hospital.


Assuntos
Microbiologia do Ar , Influenza Humana/transmissão , Orthomyxoviridae/isolamento & purificação , Aerossóis/química , China/epidemiologia , Hospitais/estatística & dados numéricos , Humanos , Influenza Humana/epidemiologia , Influenza Humana/virologia , Orthomyxoviridae/classificação , Orthomyxoviridae/genética , Orthomyxoviridae/fisiologia , Estações do Ano
10.
BMC Res Notes ; 12(1): 628, 2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31551085

RESUMO

OBJECTIVE: We conducted four cross-sectional studies over 1 year among humans and pigs in three slaughterhouses in Central and Western Kenya (> 350 km apart) to determine infection and exposure to influenza A viruses. Nasopharyngeal (NP) and oropharyngeal (OP) swabs were collected from participants who reported acute respiratory illness (ARI) defined as fever, cough or running nose. Nasal swabs and blood samples were collected from pigs. Human NP/OP and pig nasal swabs were tested for influenza A virus by real-time reverse transcriptase polymerase chain reaction (PCR) and pig serum was tested for anti-influenza A antibodies by ELISA. RESULTS: A total of 288 participants were sampled, 91.3% of them being male. Fifteen (5.2%) participants had ARI but the nine swabs collected from them were negative for influenza A virus by PCR. Of the 1128 pigs sampled, five (0.4%) nasal swabs tested positive for influenza A/H1N1/pdm09 by PCR whereas 214 of 1082 (19.8%) serum samples tested for Influenza A virus antibodies. There was higher seroprevalence in colder months and among pigs reared as free-range. These findings indicate circulation of influenza A/H1N1/pdm09 among pigs perhaps associated with good adaptation of the virus to the pig population after initial transmission from humans to pigs.


Assuntos
Matadouros , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/diagnóstico , Infecções por Orthomyxoviridae/diagnóstico , Doenças dos Suínos/diagnóstico , Adulto , Animais , Anticorpos Antivirais/sangue , Estudos Transversais , Feminino , Geografia , Humanos , Vírus da Influenza A Subtipo H1N1/fisiologia , Influenza Humana/transmissão , Influenza Humana/virologia , Quênia/epidemiologia , Masculino , Pessoa de Meia-Idade , Nasofaringe/virologia , Orofaringe/virologia , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/virologia , Pandemias , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/virologia , Adulto Jovem
11.
mSphere ; 4(5)2019 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-31533996

RESUMO

Both antiseptic hand rubbing (AHR) using ethanol-based disinfectants (EBDs) and antiseptic hand washing (AHW) are important means of infection control to prevent seasonal influenza A virus (IAV) outbreaks. However, previous reports suggest a reduced efficacy of ethanol disinfection against pathogens in mucus. We aimed to elucidate the situations and mechanisms underlying the reduced efficacy of EBDs against IAV in infectious mucus. We evaluated IAV inactivation and ethanol concentration change using IAV-infected patients' mucus (sputum). Additionally, AHR and AHW effectiveness against infectious mucus adhering to the hands and fingers was evaluated in 10 volunteers. Our clinical study showed that EBD effectiveness against IAV in mucus was extremely reduced compared to IAV in saline. IAV in mucus remained active despite 120 s of AHR; however, IAV in saline was completely inactivated within 30 s. Due to the low rate of diffusion/convection because of the physical properties of mucus as a hydrogel, the time required for the ethanol concentration to reach an IAV inactivation level and thus for EBDs to completely inactivate IAV was approximately eight times longer in mucus than in saline. On the other hand, AHR inactivated IAV in mucus within 30 s when the mucus dried completely because the hydrogel characteristics were lost. Additionally, AHW rapidly inactivated IAV. Until infectious mucus has completely dried, infectious IAV can remain on the hands and fingers, even after appropriate AHR using EBD, thereby increasing the risk of IAV transmission. We clarified the ineffectiveness of EBD use against IAV in infectious mucus.IMPORTANCE Antiseptic hand rubbing (AHR) and antiseptic hand washing (AHW) are important to prevent the spread of influenza A virus (IAV). This study elucidated the situations/mechanisms underlying the reduced efficacy of AHR against infectious mucus derived from IAV-infected individuals and indicated the weaknesses of the current hand hygiene regimens. Due to the low rate of diffusion/convection because of the physical properties of mucus as a hydrogel, the efficacy of AHR using ethanol-based disinfectant against mucus is greatly reduced until infectious mucus adhering to the hands/fingers has completely dried. If there is insufficient time before treating the next patient (i.e., if the infectious mucus is not completely dry), medical staff should be aware that effectiveness of AHR is reduced. Since AHW is effective against both dry and nondry infectious mucus, AHW should be adopted to compensate for these weaknesses of AHR.


Assuntos
Desinfetantes/farmacologia , Desinfecção das Mãos/normas , Vírus da Influenza A/efeitos dos fármacos , Influenza Humana/prevenção & controle , Muco/virologia , Etanol/farmacologia , Desinfecção das Mãos/métodos , Humanos , Controle de Infecções/métodos , Controle de Infecções/normas , Vírus da Influenza A/fisiologia , Influenza Humana/transmissão , Viabilidade Microbiana , Muco/efeitos dos fármacos , Infecções Respiratórias/prevenção & controle , Infecções Respiratórias/virologia
12.
PLoS Comput Biol ; 15(9): e1007111, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31525184

RESUMO

Prophylactic interventions such as vaccine allocation are some of the most effective public health policy planning tools. The supply of vaccines, however, is limited and an important challenge is to optimally allocate the vaccines to minimize epidemic impact. This resource allocation question (which we refer to as VaccIntDesign) has multiple dimensions: when, where, to whom, etc. Most of the existing literature in this topic deals with the latter (to whom), proposing policies that prioritize individuals by age and disease risk. However, since seasonal influenza spread has a typical spatial trend, and due to the temporal constraints enforced by the availability schedule, the when and where problems become equally, if not more, relevant. In this paper, we study the VaccIntDesign problem in the context of seasonal influenza spread in the United States. We develop a national scale metapopulation model for influenza that integrates both short and long distance human mobility, along with realistic data on vaccine uptake. We also design GreedyAlloc, a greedy algorithm for allocating the vaccine supply at the state level under temporal constraints and show that such a strategy improves over the current baseline of pro-rata allocation, and the improvement is more pronounced for higher vaccine efficacy and moderate flu season intensity. Further, the resulting strategy resembles a ring vaccination applied spatiallyacross the US.


Assuntos
Biologia Computacional/métodos , Vacinas contra Influenza/administração & dosagem , Influenza Humana , Alocação de Recursos/métodos , Análise Espaço-Temporal , Algoritmos , Bases de Dados Factuais , Humanos , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Influenza Humana/transmissão , Estações do Ano , Fatores de Tempo , Viagem/estatística & dados numéricos , Estados Unidos
13.
JAMA ; 322(9): 824-833, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31479137

RESUMO

Importance: Clinical studies have been inconclusive about the effectiveness of N95 respirators and medical masks in preventing health care personnel (HCP) from acquiring workplace viral respiratory infections. Objective: To compare the effect of N95 respirators vs medical masks for prevention of influenza and other viral respiratory infections among HCP. Design, Setting, and Participants: A cluster randomized pragmatic effectiveness study conducted at 137 outpatient study sites at 7 US medical centers between September 2011 and May 2015, with final follow-up in June 2016. Each year for 4 years, during the 12-week period of peak viral respiratory illness, pairs of outpatient sites (clusters) within each center were matched and randomly assigned to the N95 respirator or medical mask groups. Interventions: Overall, 1993 participants in 189 clusters were randomly assigned to wear N95 respirators (2512 HCP-seasons of observation) and 2058 in 191 clusters were randomly assigned to wear medical masks (2668 HCP-seasons) when near patients with respiratory illness. Main Outcomes and Measures: The primary outcome was the incidence of laboratory-confirmed influenza. Secondary outcomes included incidence of acute respiratory illness, laboratory-detected respiratory infections, laboratory-confirmed respiratory illness, and influenzalike illness. Adherence to interventions was assessed. Results: Among 2862 randomized participants (mean [SD] age, 43 [11.5] years; 2369 [82.8%]) women), 2371 completed the study and accounted for 5180 HCP-seasons. There were 207 laboratory-confirmed influenza infection events (8.2% of HCP-seasons) in the N95 respirator group and 193 (7.2% of HCP-seasons) in the medical mask group (difference, 1.0%, [95% CI, -0.5% to 2.5%]; P = .18) (adjusted odds ratio [OR], 1.18 [95% CI, 0.95-1.45]). There were 1556 acute respiratory illness events in the respirator group vs 1711 in the mask group (difference, -21.9 per 1000 HCP-seasons [95% CI, -48.2 to 4.4]; P = .10); 679 laboratory-detected respiratory infections in the respirator group vs 745 in the mask group (difference, -8.9 per 1000 HCP-seasons, [95% CI, -33.3 to 15.4]; P = .47); 371 laboratory-confirmed respiratory illness events in the respirator group vs 417 in the mask group (difference, -8.6 per 1000 HCP-seasons [95% CI, -28.2 to 10.9]; P = .39); and 128 influenzalike illness events in the respirator group vs 166 in the mask group (difference, -11.3 per 1000 HCP-seasons [95% CI, -23.8 to 1.3]; P = .08). In the respirator group, 89.4% of participants reported "always" or "sometimes" wearing their assigned devices vs 90.2% in the mask group. Conclusions and Relevance: Among outpatient health care personnel, N95 respirators vs medical masks as worn by participants in this trial resulted in no significant difference in the incidence of laboratory-confirmed influenza. Trial Registration: ClinicalTrials.gov Identifier: NCT01249625.


Assuntos
Pessoal de Saúde , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Influenza Humana/prevenção & controle , Influenza Humana/transmissão , Máscaras , Dispositivos de Proteção Respiratória , Adulto , Assistência Ambulatorial , Feminino , Humanos , Incidência , Controle de Infecções/métodos , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional , Infecções Respiratórias/prevenção & controle , Infecções Respiratórias/transmissão
14.
Nat Commun ; 10(1): 3526, 2019 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-31387995

RESUMO

Segmentation of viral genomes into multiple RNAs creates the potential for replication of incomplete viral genomes (IVGs). Here we use a single-cell approach to quantify influenza A virus IVGs and examine their fitness implications. We find that each segment of influenza A/Panama/2007/99 (H3N2) virus has a 58% probability of being replicated in a cell infected with a single virion. Theoretical methods predict that IVGs carry high costs in a well-mixed system, as 3.6 virions are required for replication of a full genome. Spatial structure is predicted to mitigate these costs, however, and experimental manipulations of spatial structure indicate that local spread facilitates complementation. A virus entirely dependent on co-infection was used to assess relevance of IVGs in vivo. This virus grows robustly in guinea pigs, but is less infectious and does not transmit. Thus, co-infection allows IVGs to contribute to within-host spread, but complete genomes may be critical for transmission.


Assuntos
Vírus Defeituosos/patogenicidade , Genoma Viral , Vírus da Influenza A Subtipo H3N2/patogenicidade , Influenza Humana/transmissão , Replicação Viral/genética , Animais , Vírus Defeituosos/genética , Modelos Animais de Doenças , Cães , Evolução Molecular , Feminino , Cobaias , Células HEK293 , Humanos , Vírus da Influenza A Subtipo H3N2/genética , Influenza Humana/virologia , Funções Verossimilhança , Células Madin Darby de Rim Canino , Modelos Biológicos , RNA Viral/genética , Análise de Célula Única , Carga Viral , Vírion/genética , Eliminação de Partículas Virais/genética
15.
mSphere ; 4(4)2019 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-31434749

RESUMO

Highly transmissible influenza viruses (IV) must remain stable and infectious under a wide range of environmental conditions following release from the respiratory tract into the air. Understanding how expelled IV persist in the environment is critical to limiting the spread of these viruses. Little is known about how the stability of different IV in expelled aerosols is impacted by exposure to environmental stressors, such as relative humidity (RH). Given that not all IV are equally capable of efficient airborne transmission in people, we anticipated that not all IV would respond uniformly to ambient RH. Therefore, we have examined the stability of human-pathogenic seasonal and avian IV in suspended aerosols and stationary droplets under a range of RH conditions. H3N2 and influenza B virus (IBV) isolates are resistant to RH-dependent decay in aerosols in the presence of human airway surface liquid, but we observed strain-dependent variations in the longevities of H1N1, H3N2, and IBV in droplets. Surprisingly, low-pathogenicity avian influenza H6N1 and H9N2 viruses, which cause sporadic infections in humans but are unable to transmit person to person, demonstrated a trend toward increased sensitivity at midrange to high-range RH. Taken together, our observations suggest that the levels of vulnerability to decay at midrange RH differ with virus type and host origin.IMPORTANCE The rapid spread of influenza viruses (IV) from person to person during seasonal epidemics causes acute respiratory infections that can lead to hospitalizations and life-threatening illness. Atmospheric conditions such as relative humidity (RH) can impact the viability of IV released into the air. To understand how different IV are affected by their environment, we compared the levels of stability of human-pathogenic seasonal and avian IV under a range of RH conditions and found that highly transmissible seasonal IV were less sensitive to decay under midrange RH conditions in droplets. We observed that certain RH conditions can support the persistence of infectious viruses on surfaces and in the air for extended periods of time. Together, our findings will facilitate understanding of factors affecting the persistence and spread of IV in our environment.


Assuntos
Microbiologia Ambiental , Interações Hospedeiro-Patógeno , Viabilidade Microbiana , Orthomyxoviridae/fisiologia , Aerossóis , Animais , Aves , Humanos , Umidade , Vírus da Influenza A Subtipo H1N1/fisiologia , Vírus da Influenza A Subtipo H3N2/fisiologia , Vírus da Influenza A Subtipo H9N2/fisiologia , Influenza Aviária/virologia , Influenza Humana/transmissão , Influenza Humana/virologia , Orthomyxoviridae/classificação , Temperatura Ambiente
16.
Environ Health Prev Med ; 24(1): 53, 2019 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-31421676

RESUMO

BACKGROUND: Influenza A viruses pose a significant risk to human health because of their wide host range and ability to reassort into novel viruses that can cause serious disease and pandemics. Since transmission of these viruses between humans and pigs can be associated with occupational and environmental exposures, we investigated the association between occupational exposure to pigs, occurrence of acute respiratory illness (ARI), and influenza A virus infection. METHODS: The study was conducted in Kiambu County, the county with the highest level of intensive small-scale pig farming in Kenya. Up to 3 participants (> 2 years old) per household from pig-keeping and non-pig-keeping households were randomly recruited and followed up in 2013 (Sept-Dec) and 2014 (Apr-Aug). Oropharyngeal (OP) and nasopharyngeal (NP) swabs were collected from participants with ARI at the time of study visit. For the animal study, nasal and oropharyngeal swabs, and serum samples were collected from pigs and poultry present in enrolled households. The human and animal swab samples were tested for viral nucleic acid by RT-PCR and sera by ELISA for antibodies. A Poisson generalized linear mixed-effects model was developed to assess the association between pig exposure and occurrence of ARI. RESULTS: Of 1137 human participants enrolled, 625 (55%) completed follow-up visits including 172 (27.5%) pig workers and 453 (72.5%) non-pig workers. Of 130 human NP/OP swabs tested, four (3.1%) were positive for influenza A virus, one pig worker, and three among non-pig workers. Whereas none of the 4462 swabs collected from pig and poultry tested positive for influenza A virus by RT-PCR, 265 of 4273 (6.2%) of the sera tested positive for virus antibodies by ELISA, including 11.6% (230/1990) of the pigs and 1.5% (35/2,283) of poultry. The cumulative incidence of ARI was 16.9% among pig workers and 26.9% among the non-pig workers. The adjusted risk ratio for the association between being a pig worker and experiencing an episode of ARI was 0.56 (95% CI [0.33, 0.93]), after adjusting for potential confounders. CONCLUSIONS: Our findings demonstrate moderate seropositivity for influenza A virus among pigs, suggesting the circulation of swine influenza virus and a potential for interspecies transmission.


Assuntos
Vírus da Influenza A/fisiologia , Influenza Humana/epidemiologia , Infecções por Orthomyxoviridae/epidemiologia , Zoonoses/epidemiologia , Adolescente , Adulto , Animais , Anticorpos Antivirais/sangue , Criança , Feminino , Humanos , Incidência , Vírus da Influenza A/genética , Vírus da Influenza A/imunologia , Influenza Humana/transmissão , Influenza Humana/virologia , Quênia/epidemiologia , Masculino , Pessoa de Meia-Idade , Infecções por Orthomyxoviridae/transmissão , Faringe/virologia , Aves Domésticas/virologia , RNA Viral/genética , Fatores de Risco , Estudos Soroepidemiológicos , Suínos/virologia , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/transmissão , Adulto Jovem , Zoonoses/transmissão
17.
Int J Infect Dis ; 88: 113-119, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31401200

RESUMO

Here we review evidence for influenza A viruses (IAVs) moving from swine, avian, feline, equine, and canine species to infect humans. We review case reports, sero-epidemiological, archeo-epidemiological, environmental, and historical studies and consider trends in livestock farming. Although this focused review is not systematic, the aggregated data point to industrialized swine farming as the most likely source of future pandemic viruses, yet IAV surveillance on such farms is remarkably sparse. We recommend increased biosafety and biosecurity training for farm administrators and swine workers with One Health-oriented virus surveillance throughout industrialized farming and meat production lines. Collaborative partnerships with human medical researchers could aid in efforts to mitigate emerging virus threats by offering new surveillance and diagnostic technologies to livestock farming industries.


Assuntos
Vírus da Influenza A/fisiologia , Influenza Humana/virologia , Infecções por Orthomyxoviridae/veterinária , Animais , Aves , Gatos , Cães , Cavalos , Humanos , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Humana/transmissão , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/virologia , Suínos
18.
BMC Infect Dis ; 19(1): 446, 2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-31113375

RESUMO

BACKGROUND: Detailed knowledge about viral respiratory disease transmission dynamics within healthcare institutions is essential for effective infection control policy and practice. In the quest to study viral transmission pathways, we aimed to investigate recruitment rates and adherence of healthcare workers (HCWs) and hospital inpatients with a study protocol that involves prospective surveillance based on daily mid-turbinate nasal swabs and illness diaries. METHODS: Single center prospective surveillance of patients and HCWs in three different hospital departments of a tertiary care center during an entire influenza season in Switzerland. Inpatients and acute care HCWs were asked to provide mid-turbinate nasal swabs and illness diaries on a daily basis. Study protocol adherence and recruitment rates were the primary outcomes of interest. RESULTS: A total 251 participants (59 (23.5%) health care workers and 192 (76.5%) inpatients) were recruited from three different hospital wards. Recruitment rates differed between HCWs (62.1% of eligible HCWs) and inpatients (32.5%; P < 0.001), but not within HCWs (P = 0.185) or inpatients (P = 0.301) of the three departments. The total number of study-days was 7874; 2321 (29.5%) for inpatients and 5553 (70.5%) for HCWs. HCWs were followed for a median of 96 days (range, 71-96 days) and inpatients for 8 days (range, 3-77 days). HCWs provided swabs on 73% (range, 0-100%) of study days, and diaries on 77% (range 0-100%). Inpatients provided swabs and diaries for 83% (range, 0-100%) of days in hospital. In HCWs, increasing age, working in internal medicine and longer duration of total study participation were positively associated with the proportion of swabs and diaries collected. Adherence to the study protocol was significantly lower in physicians as compared to nurses for both swabs (P = 0.042) and diaries (P = 0.033). In inpatients, no association between demographic factors and adherence was detected. Conclusions Prospective surveillance of respiratory viral disease was feasible in a cohort of inpatients and HCWs over an entire influenza season, both in terms of recruitment rates and adherence to a study protocol that included daily specimen collection and illness diaries. TRIAL REGISTRATION: clinicaltrials.gov NCT02478905 . Date of registration June 23, 2015.


Assuntos
Pessoal de Saúde/psicologia , Pessoal de Saúde/estatística & dados numéricos , Influenza Humana/transmissão , Pacientes Internados/psicologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Fidelidade a Diretrizes , Humanos , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Pacientes Internados/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Suíça , Centros de Atenção Terciária/estatística & dados numéricos , Adulto Jovem
19.
PLoS One ; 14(5): e0216478, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31067261

RESUMO

Infectious virus-laden aerosols generated during poultry processing may mediate airborne transmissions of avian influenza at live poultry markets. To develop effective control measures to reduce aerosol dispersion, we characterised the aerosol flow pattern of the mechanical defeatherers, a major source of aerosol dispersion during poultry processing at live poultry markets in China. Mechanical defeatherers create a strong air circulation during operation with inflow and outflow velocities over 1 m/s. A partial lid was designed to suppress the outflow and reduce aerosol dispersion. Computational fluid dynamics simulations confirmed that the partial lid prototype reduced the aerosol escape rate by over 65%. To validate the effectiveness of the partial lid in reducing aerosol dispersion, a field study was conducted at a retail poultry shop in Guangzhou and the concentrations of influenza viral RNA and avian 18S rRNA dispersed in air were monitored during poultry processing, with and without the use of the partial lid. At the breathing zone of the poultry worker, the use of the partial lid effectively suppressed the upward airflow and reduced the concentration of avian 18S rRNA in the air by 57%. The economic and practical partial lid can be easily implemented to reduce generation of influenza virus-laden aerosols at live poultry markets.


Assuntos
Indústria de Processamento de Alimentos , Vírus da Influenza A , Influenza Aviária/transmissão , Influenza Humana/transmissão , Modelos Biológicos , Doenças das Aves Domésticas/transmissão , Aves Domésticas , Aerossóis , Animais , China , Humanos
20.
Artigo em Inglês | MEDLINE | ID: mdl-30959783

RESUMO

The 2009 pandemic influenza virus caused the majority of the influenza A virus infections in China in 2009. It arrived in several Chinese cities from imported cases and then spread as people travelled domestically by all means of transportation, among which road traffic was the most commonly used for daily commuting. Spatial variation in socioeconomic status not only accelerates migration across regions but also partly induces the differences in epidemic processes and in responses to epidemics across regions. However, the roles of both road travel and socioeconomic factors have not received the attention they deserve. Here, we constructed a national highway network for and between 333 cities in mainland China and extracted epidemiological variables and socioeconomic factors for each city. We calculated classic centrality measures for each city in the network and proposed two new measures (SumRatio and Multicenter Distance). We evaluated the correlation between the centrality measures and epidemiological features and conducted a spatial autoregression to quantify the impacts of road network and socioeconomic factors during the outbreak. The results showed that epidemics had more significant relationships with both our new measures than the classic ones. Higher population density, higher per person income, larger SumRatio and Multicenter Distance, more hospitals and college students, and lower per person GDP were associated with higher cumulative incidence. Higher population density and number of slaughtered pigs were found to advance epidemic arrival time. Higher population density, more colleges and slaughtered pigs, and lower Multicenter Distance were associated with longer epidemic duration. In conclusion, road transport and socioeconomic status had significant impacts and should be considered for the prevention and control of future pandemics.


Assuntos
Surtos de Doenças/estatística & dados numéricos , Epidemias/estatística & dados numéricos , Influenza Humana/epidemiologia , Influenza Humana/transmissão , Transportes/estatística & dados numéricos , Viagem/estatística & dados numéricos , China/epidemiologia , Humanos , Incidência , Classe Social , Fatores Socioeconômicos
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