RESUMO
The emergence of the novel Middle East (ME) respiratory syndrome coronavirus (MERS-CoV) has raised global public health concerns regarding the current situation and its future evolution. Here we propose an integrative maximum likelihood analysis of both cluster data in the ME and importations in a set of European countries to assess the transmission scenario and incidence of sporadic infections. Our approach is based on a spatial-transmission model integrating mobility data worldwide and allows for variations in the zoonotic/environmental transmission and under-ascertainment. Maximum likelihood estimates for the ME, considering outbreak data up to 31 August 2013, indicate the occurrence of a subcritical epidemic with a reproductive number R of 0.50 (95% confidence interval (CI): 0.30-0.77) associated with a daily rate of sporadic introductions psp of 0.28 (95% CI: 0.12-0.85). Infections in the ME appear to be mainly dominated by zoonotic/environmental transmissions, with possible under-ascertainment (ratio of estimated to observed (0.116) sporadic cases equal to 2.41, 95% CI: 1.03-7.32). No time evolution of the situation emerges. Analyses of flight passenger data from ME countries indicate areas at high risk of importation. While dismissing an immediate threat for global health security, this analysis provides a baseline scenario for future reference and updates, suggests reinforced surveillance to limit under-ascertainment, and calls for alertness in high importation risk areas worldwide.
Assuntos
Infecções por Coronavirus/transmissão , Coronavirus/isolamento & purificação , Epidemias/estatística & dados numéricos , Infecções Respiratórias/transmissão , Infecções por Coronavirus/epidemiologia , Reservatórios de Doenças/virologia , Saúde Global , Humanos , Funções Verossimilhança , Oriente Médio/epidemiologia , Infecções Respiratórias/epidemiologia , Medição de RiscoRESUMO
Chikungunya fever (CHIKV), a viral disease transmitted by mosquitoes, is currently affecting several areas in the Caribbean. The vector is found in the Americas from southern Florida to Brazil, and the Caribbean is a highly connected region in terms of population movements. There is therefore a significant risk for the epidemic to quickly expand to a wide area in the Americas. Here, we describe the spread of CHIKV in the first three areas to report cases and between areas in the region. Local transmission of CHIKV in the Caribbean is very effective, the mean number of cases generated by a human case ranging from two to four. There is a strong spatial signature in the regional epidemic, with the risk of transmission between areas estimated to be inversely proportional to the distance rather than driven by air transportation. So far, this simple distance-based model has successfully predicted observed patterns of spread. The spatial structure allows ranking areas according to their risk of invasion. This characterisation may help national and international agencies to optimise resource allocation for monitoring and control and encourage areas with elevated risks to act.
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Infecções por Alphavirus/transmissão , Infecções por Alphavirus/virologia , Vírus Chikungunya/isolamento & purificação , Aedes/virologia , Infecções por Alphavirus/diagnóstico , Animais , Região do Caribe , Febre de Chikungunya , Vírus Chikungunya/genética , Atrofia Geográfica , Humanos , Insetos Vetores/virologia , Cadeias de Markov , Método de Monte Carlo , ViagemRESUMO
The quick spread of an Ebola outbreak in West Africa has led a number of countries and airline companies to issue travel bans to the affected areas. Considering data up to 31 Aug 2014, we assess the impact of the resulting traffic reductions with detailed numerical simulations of the international spread of the epidemic. Traffic reductions are shown to delay by only a few weeks the risk that the outbreak extends to new countries.
Assuntos
Aeronaves , Surtos de Doenças , Doença pelo Vírus Ebola/prevenção & controle , Viagem , África Ocidental/epidemiologia , Saúde Global , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/transmissão , HumanosRESUMO
BACKGROUND: The knowledge of risk perceptions in primary care could help health authorities to manage epidemics. METHODS: A European multi-center cross-sectional study was conducted in France, Belgium and Spain to describe the perceptions, the level of anxiety and the feeling of preparedness of primary healthcare physicians towards the COVID-19 infection at the beginning of the pandemic. The factors associated with the feeling of preparedness were studied using multivariate logistic regressions. RESULTS: A total of 511 physicians participated to the study (response rate: 35.2%). Among them, only 16.3% (n=82) were highly anxious about the pandemic, 50.6% (n=254) had the feeling to have a high level of information, 80.5% (n=409) found the measures taken by the health authorities suitable to limit the spread of COVID-19, and 45.2% (n=229) felt prepared to face the epidemic. Factors associated with feeling prepared were: being a Spanish practitioner (adjusted OR=4.34; 95%CI [2.47; 7.80]), being a man (aOR=2.57, 95%CI [1.69; 3.96]), finding the measures taken by authorities appropriate (aOR=1.72, 95%CI [1.01; 3.00]) and being highly informed (aOR=4.82, 95%CI [2.62; 9.19]). CONCLUSIONS: Regarding the dramatic evolution of the pandemic in Europe in the weeks following the study, it appears that information available at this time and transmitted to the physicians could have given a wrong assessment of the spread and the severity of the disease. It seems essential to better integrate the primary care physicians into the information, training and protection channels. A comparison between countries could help to select the most effective measures in terms of information and communication.
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COVID-19 , Médicos de Atenção Primária , Bélgica/epidemiologia , Estudos Transversais , França/epidemiologia , Humanos , Masculino , Pandemias/prevenção & controle , Percepção , SARS-CoV-2 , Espanha/epidemiologiaRESUMO
To overcome the limitations of the state-of-the-art influenza surveillance systems in Europe, we established in 2008 a European-wide consortium aimed at introducing an innovative information and communication technology approach for a web-based surveillance system across different European countries, called Influenzanet. The system, based on earlier efforts in The Netherlands and Portugal, works with the participation of the population in each country to collect real-time information on the distribution of influenza-like illness cases through web surveys administered to volunteers reporting their symptoms (or lack of symptoms) every week during the influenza season. Such a large European-wide web-based monitoring infrastructure is intended to rapidly identify public health emergencies, contribute to understanding global trends, inform data-driven forecast models to assess the impact on the population, optimize the allocation of resources, and help in devising mitigation and containment measures. In this article, we describe the scientific and technological issues faced during the development and deployment of a flexible and readily deployable web tool capable of coping with the requirements of different countries for data collection, during either a public health emergency or an ordinary influenza season. Even though the system is based on previous successful experience, the implementation in each new country represented a separate scientific challenge. Only after more than 5 years of development are the existing platforms based on a plug-and-play tool that can be promptly deployed in any country wishing to be part of the Influenzanet network, now composed of The Netherlands, Belgium, Portugal, Italy, the UK, France, Sweden, Spain, Ireland, and Denmark.
Assuntos
Monitoramento Epidemiológico , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Internet , Vigilância em Saúde Pública , Pesquisa Participativa Baseada na Comunidade , Surtos de Doenças/estatística & dados numéricos , Europa (Continente)/epidemiologia , Inquéritos Epidemiológicos , HumanosRESUMO
The unfolding of pandemic influenza A(H1N1) for Fall 2009 in the Northern Hemisphere is still uncertain. Plans for vaccination campaigns and vaccine trials are underway, with the first batches expected to be available early October. Several studies point to the possibility of an anticipated pandemic peak that could undermine the effectiveness of vaccination strategies. Here, we use a structured global epidemic and mobility metapopulation model to assess the effectiveness of massive vaccination campaigns for the Fall/Winter 2009. Mitigation effects are explored depending on the interplay between the predicted pandemic evolution and the expected delivery of vaccines. The model is calibrated using recent estimates on the transmissibility of the new A(H1N1) influenza. Results show that if additional intervention strategies were not used to delay the time of pandemic peak, vaccination may not be able to considerably reduce the cumulative number of cases, even when the mass vaccination campaign is started as early as mid-October. Prioritized vaccination would be crucial in slowing down the pandemic evolution and reducing its burden.
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The global spread of emergent diseases is inevitably entangled with the structure of the population flows among different geographical regions. The airline transportation network in particular shrinks the geographical space by reducing travel time between the world's most populated areas and defines the main channels along which emergent diseases will spread. In this paper, we investigate the role of the large-scale properties of the airline transportation network in determining the global propagation pattern of emerging diseases. We put forward a stochastic computational framework for the modeling of the global spreading of infectious diseases that takes advantage of the complete International Air Transport Association 2002 database complemented with census population data. The model is analyzed by using for the first time an information theory approach that allows the quantitative characterization of the heterogeneity level and the predictability of the spreading pattern in presence of stochastic fluctuations. In particular we are able to assess the reliability of numerical forecast with respect to the intrinsic stochastic nature of the disease transmission and travel flows. The epidemic pattern predictability is quantitatively determined and traced back to the occurrence of epidemic pathways defining a backbone of dominant connections for the disease spreading. The presented results provide a general computational framework for the analysis of containment policies and risk forecast of global epidemic outbreaks.