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2.
Int J Infect Dis ; 141: 106943, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38266976

RESUMEN

OBJECTIVES: NTDs historically receive less attention than other diseases in the same regions. Recent gap analyses revealed notable shortcomings despite NTD elimination progress. This systematic scoping review was conducted to understand NTD control, elimination, and eradication efforts in the WHO African region over the last 30 years. METHODS: Peer-reviewed publications from PubMed, Web of Science, and Cochrane databases related to NTD control, elimination, and eradication in the WHO African Region from 1990 to 2022 were reviewed. Included articles were categorized based on NTD; study location, type, and period; and topic areas. Technical and guidance documents from WHO, UN, partner, and academic/research institutions were reviewed. Country-specific multi-year NTD master plans were documented. RESULTS: Four hundred eighty peer-reviewed articles, six Cochrane reviews, and 134 technical reports were included. MDA and non-interventional/survey-related studies were common topics. Lymphatic filariasis, trachoma, schistosomiasis, and onchocerciasis were the most frequently studied NTDs. Tanzania, Ethiopia, and Nigeria were the most represented countries; multi-country studies were limited. CONCLUSION: The review highlights progress made in NTD control, elimination, and eradication efforts in the WHO African Region and can inform national/regional strategies. Disease and geographical disparities were evident, warranting focus and research in certain countries. A standardized approach to NTD control programs is needed for sustained progress. FUNDING: There was no funding source for this study.


Asunto(s)
Oncocercosis , Esquistosomiasis , Medicina Tropical , Humanos , Enfermedades Desatendidas/epidemiología , Enfermedades Desatendidas/prevención & control , Organización Mundial de la Salud , Etiopía , Oncocercosis/epidemiología , Oncocercosis/prevención & control
3.
CJEM ; 25(10): 796-798, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37737538
4.
Nature ; 619(7971): 782-787, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37438520

RESUMEN

Many communities in low- and middle-income countries globally lack sustainable, cost-effective and mutually beneficial solutions for infectious disease, food, water and poverty challenges, despite their inherent interdependence1-7. Here we provide support for the hypothesis that agricultural development and fertilizer use in West Africa increase the burden of the parasitic disease schistosomiasis by fuelling the growth of submerged aquatic vegetation that chokes out water access points and serves as habitat for freshwater snails that transmit Schistosoma parasites to more than 200 million people globally8-10. In a cluster randomized controlled trial (ClinicalTrials.gov: NCT03187366) in which we removed invasive submerged vegetation from water points at 8 of 16 villages (that is, clusters), control sites had 1.46 times higher intestinal Schistosoma infection rates in schoolchildren and lower open water access than removal sites. Vegetation removal did not have any detectable long-term adverse effects on local water quality or freshwater biodiversity. In feeding trials, the removed vegetation was as effective as traditional livestock feed but 41 to 179 times cheaper and converting the vegetation to compost provided private crop production and total (public health plus crop production benefits) benefit-to-cost ratios as high as 4.0 and 8.8, respectively. Thus, the approach yielded an economic incentive-with important public health co-benefits-to maintain cleared waterways and return nutrients captured in aquatic plants back to agriculture with promise of breaking poverty-disease traps. To facilitate targeting and scaling of the intervention, we lay the foundation for using remote sensing technology to detect snail habitats. By offering a rare, profitable, win-win approach to addressing food and water access, poverty alleviation, infectious disease control and environmental sustainability, we hope to inspire the interdisciplinary search for planetary health solutions11 to the many and formidable, co-dependent global grand challenges of the twenty-first century.


Asunto(s)
Agricultura , Ecosistema , Salud Rural , Esquistosomiasis , Caracoles , Animales , Niño , Humanos , Esquistosomiasis/epidemiología , Esquistosomiasis/prevención & control , Esquistosomiasis/transmisión , Caracoles/parasitología , África Occidental , Fertilizantes , Especies Introducidas , Intestinos/parasitología , Agua Dulce , Plantas/metabolismo , Biodiversidad , Alimentación Animal , Calidad del Agua , Producción de Cultivos/métodos , Salud Pública , Pobreza/prevención & control , Organismos Acuáticos/metabolismo , Tecnología de Sensores Remotos
5.
Arch Toxicol ; 96(11): 2935-2945, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35962200

RESUMEN

Synthetic cannabinoid receptor agonists (SCRAs) pose a danger to public health. This study focused on individuals experiencing recreational drug toxicity who had used 5F-MDMB-PICA.Patient records were evaluated regarding vital signs, Glasgow Coma Scale (GCS) and clinical features. Liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) confirmed and quantified the presence of 5F-MDMB-PICA (and/or metabolites) as the only SCRA present in the serum of 71 patients. Cannabinoid activity was evaluated by a cannabinoid receptor (CB1) bioassay, to assess the relationship between serum concentrations and ex vivo human CB1 activation potential. Furthermore, a link with the clinical presentation was appraised.5F-MDMB-PICA and five metabolites were pharmacologically profiled in vitro, revealing theoretically possible contributions of two active in vivo metabolites to overall cannabinoid activity. Serum concentrations of 5F-MDMB-PICA were correlated to the ex vivo cannabinoid activity, revealing a sigmoidal relationship. The latter could also be predicted based on pharmacological characterization of 5F-MDMB-PICA and its metabolites and an in-depth investigation of the bioassay outcome. Clinically, the GCS showed a significant trend (decrease) with increasing ex vivo cannabinoid activity.This is the first study to evaluate possible toxic effects of 5F-MDMB-PICA in a unique large patient cohort. It allows a better understanding of 5F-MDMB-PICA and metabolites in humans, suggesting a negligible contribution by 5F-MDMB-PICA metabolites to the overall cannabinoid activity in serum. Additionally, this work shows that in vitro pharmacological characterization allows close prediction of an individual's ex vivo CB1 activity, the latter showing a relationship with the level of consciousness.


Asunto(s)
Cannabinoides , Drogas Ilícitas , Agonistas de Receptores de Cannabinoides/farmacología , Cannabinoides/metabolismo , Humanos , Drogas Ilícitas/química , Receptor Cannabinoide CB1 , Receptores de Cannabinoides
6.
Clin Chem ; 68(7): 906-916, 2022 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-35266984

RESUMEN

BACKGROUND: Synthetic cannabinoid receptor agonists (SCRAs) are amongst the largest groups of new psychoactive substances (NPS). Their often high activity at the CB1 cannabinoid receptor frequently results in intoxication, imposing serious health risks. Hence, continuous monitoring of these compounds is important, but challenged by the rapid emergence of novel analogues that are missed by traditional targeted detection strategies. We addressed this need by performing an activity-based, universal screening on a large set (n = 968) of serum samples from patients presenting to the emergency department with acute recreational drug or NPS toxicity. METHODS: We assessed the performance of an activity-based method in detecting newly circulating SCRAs compared with liquid chromatography coupled to high-resolution mass spectrometry. Additionally, we developed and evaluated machine learning models to reduce the screening workload by automating interpretation of the activity-based screening output. RESULTS: Activity-based screening delivered outstanding performance, with a sensitivity of 94.6% and a specificity of 98.5%. Furthermore, the developed machine learning models allowed accurate distinction between positive and negative patient samples in an automatic manner, closely matching the manual scoring of samples. The performance of the model depended on the predefined threshold, e.g., at a threshold of 0.055, sensitivity and specificity were both 94.0%. CONCLUSION: The activity-based bioassay is an ideal candidate for untargeted screening of novel SCRAs. The combination of this universal screening assay and a machine learning approach for automated sample scoring is a promising complement to conventional analytical methods in clinical practice.


Asunto(s)
Cannabinoides , Drogas Ilícitas , Agonistas de Receptores de Cannabinoides/farmacología , Cromatografía Liquida/métodos , Humanos , Aprendizaje Automático
8.
Epidemiol Infect ; 149: e263, 2021 11 04.
Artículo en Inglés | MEDLINE | ID: mdl-34732270

RESUMEN

The World Health Organization African region recorded its first laboratory-confirmed coronavirus disease-2019 (COVID-19) cases on 25 February 2020. Two months later, all the 47 countries of the region were affected. The first anniversary of the pandemic occurred in a changed context with the emergence of new variants of concern (VOC) and growing COVID-19 fatigue. This study describes the epidemiological trajectory of COVID-19 in the region, summarises public health and social measures (PHSM) implemented and discusses their impact on the pandemic trajectory. As of 24 February 2021, the African region accounted for 2.5% of cases and 2.9% of deaths reported globally. Of the 13 countries that submitted detailed line listing of cases, the proportion of cases with at least one co-morbid condition was estimated at 3.3% of all cases. Hypertension, diabetes and human immunodeficiency virus (HIV) infection were the most common comorbid conditions, accounting for 11.1%, 7.1% and 5.0% of cases with comorbidities, respectively. Overall, the case fatality ratio (CFR) in patients with comorbid conditions was higher than in patients without comorbid conditions: 5.5% vs. 1.0% (P < 0.0001). Countries started to implement lockdown measures in early March 2020. This contributed to slow the spread of the pandemic at the early stage while the gradual ease of lockdowns from 20 April 2020 resulted in an upsurge. The second wave of the pandemic, which started in November 2020, coincided with the emergence of the new variants of concern. Only 0.08% of the population from six countries received at least one dose of the COVID-19 vaccine. It is critical to not only learn from the past 12 months to improve the effectiveness of the current response but also to start preparing the health systems for subsequent waves of the current pandemic and future pandemics.


Asunto(s)
COVID-19/epidemiología , COVID-19/mortalidad , SARS-CoV-2 , Organización Mundial de la Salud/organización & administración , África/epidemiología , Comorbilidad , Humanos , Factores de Riesgo , Factores de Tiempo
9.
Epidemiol Infect ; 149: e264, 2021 11 04.
Artículo en Inglés | MEDLINE | ID: mdl-34732273

RESUMEN

As of 03 January 2021, the WHO African region is the least affected by the coronavirus disease-2019 (COVID-19) pandemic, accounting for only 2.4% of cases and deaths reported globally. However, concerns abound about whether the number of cases and deaths reported from the region reflect the true burden of the disease and how the monitoring of the pandemic trajectory can inform response measures.We retrospectively estimated four key epidemiological parameters (the total number of cases, the number of missed cases, the detection rate and the cumulative incidence) using the COVID-19 prevalence calculator tool developed by Resolve to Save Lives. We used cumulative cases and deaths reported during the period 25 February to 31 December 2020 for each WHO Member State in the region as well as population data to estimate the four parameters of interest. The estimated number of confirmed cases in 42 countries out of 47 of the WHO African region included in this study was 13 947 631 [95% confidence interval (CI): 13 334 620-14 635 502] against 1 889 512 cases reported, representing 13.5% of overall detection rate (range: 4.2% in Chad, 43.9% in Guinea). The cumulative incidence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was estimated at 1.38% (95% CI: 1.31%-1.44%), with South Africa the highest [14.5% (95% CI: 13.9%-15.2%)] and Mauritius [0.1% (95% CI: 0.099%-0.11%)] the lowest. The low detection rate found in most countries of the WHO African region suggests the need to strengthen SARS-CoV-2 testing capacities and adjusting testing strategies.


Asunto(s)
COVID-19/diagnóstico , COVID-19/epidemiología , SARS-CoV-2 , Organización Mundial de la Salud/organización & administración , África/epidemiología , Anciano , COVID-19/mortalidad , COVID-19/virología , Humanos , Incidencia , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo
10.
Epidemiol Infect ; 149: e258, 2021 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-34493348

RESUMEN

Experience gained from responding to major outbreaks may have influenced the early coronavirus disease-2019 (COVID-19) pandemic response in several countries across Africa. We retrospectively assessed whether Guinea, Liberia and Sierra Leone, the three West African countries at the epicentre of the 2014-2016 Ebola virus disease outbreak, leveraged the lessons learned in responding to COVID-19 following the World Health Organization's (WHO) declaration of a public health emergency of international concern (PHEIC). We found relatively lower incidence rates across the three countries compared to many parts of the globe. Time to case reporting and laboratory confirmation also varied, with Guinea and Liberia reporting significant delays compared to Sierra Leone. Most of the selected readiness measures were instituted before confirmation of the first case and response measures were initiated rapidly after the outbreak confirmation. We conclude that the rapid readiness and response measures instituted by the three countries can be attributed to their lessons learned from the devastating Ebola outbreak, although persistent health systems weaknesses and the unique nature of COVID-19 continue to challenge control efforts.


Asunto(s)
COVID-19/epidemiología , Ebolavirus , Fiebre Hemorrágica Ebola/epidemiología , África Occidental/epidemiología , Atención a la Salud , Humanos , Incidencia , SARS-CoV-2 , Factores de Tiempo
11.
Epidemiol Infect ; 149: e256, 2021 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-34392872

RESUMEN

This study analysed the reported incidence of COVID-19 and associated epidemiological and socio-economic factors in the WHO African region. Data from COVID-19 confirmed cases and SARS-CoV-2 tests reported to the WHO by Member States between 25 February and 31 December 2020 and publicly available health and socio-economic data were analysed using univariate and multivariate binomial regression models. The overall cumulative incidence was 1846 cases per million population. Cape Verde (21 350 per million), South Africa (18 060 per million), Namibia (9840 per million), Eswatini (8151 per million) and Botswana (6044 per million) recorded the highest cumulative incidence, while Benin (260 per million), Democratic Republic of Congo (203 per million), Niger (141 cases per million), Chad (133 per million) and Burundi (62 per million) recorded the lowest. Increasing percentage of urban population (ß = -0.011, P = 0.04) was associated with low cumulative incidence, while increasing number of cumulative SARS-CoV-2 tests performed per 10 000 population (ß = 0.0006, P = 0.006) and the proportion of population aged 15-64 years (adjusted ß = 0.174, P < 0.0001) were associated with high COVID-19 cumulative incidence. With limited testing capacities and overwhelmed health systems, these findings highlight the need for countries to increase and decentralise testing capacities and adjust testing strategies to target most at-risk populations.


Asunto(s)
COVID-19/epidemiología , SARS-CoV-2 , Organización Mundial de la Salud , Adolescente , Adulto , África/epidemiología , Humanos , Incidencia , Modelos Logísticos , Persona de Mediana Edad , Análisis Multivariante , Estudios Retrospectivos , Factores de Tiempo , Adulto Joven
12.
Epidemiol Infect ; 149: e260, 2021 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-34036928

RESUMEN

The rapid transmissibility of the severe acute respiratory syndrome-coronavirus-2 causing coronavirus disease-2019, requires timely dissemination of information and public health responses, with all 47 countries of the WHO African Region simultaneously facing significant risk, in contrast to the usual highly localised infectious disease outbreaks. This demanded a different approach to information management and an adaptive information strategy was implemented, focusing on data collection and management, reporting and analysis at the national and regional levels. This approach used frugal innovation, building on tools and technologies that are commonly used, and well understood; as well as developing simple, practical, highly functional and agile solutions that could be rapidly and remotely implemented, and flexible enough to be recalibrated and adapted as required. While the approach was successful in its aim of allowing the WHO Regional Office for Africa (WHO AFRO) to gather surveillance and epidemiological data, several challenges were encountered that affected timeliness and quality of data captured and reported by the member states, showing that strengthening data systems and digital capacity, and encouraging openness and data sharing are an important component of health system strengthening.


Asunto(s)
COVID-19/epidemiología , Gestión de la Información , Organización Mundial de la Salud/organización & administración , África/epidemiología , Atención a la Salud , Humanos , SARS-CoV-2
13.
Epidemiol Infect ; 149: e259, 2021 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-33966683

RESUMEN

Successive waves of COVID-19 transmission have led to exponential increases in new infections globally. In this study, we have applied a decision-making tool to assess the risk of continuing transmission to inform decisions on tailored public health and social measures (PHSM) using data on cases and deaths reported by Member States to the WHO Regional Office for Africa as of 31 December 2020. Transmission classification and health system capacity were used to assess the risk level of each country to guide implementation and adjustments to PHSM. Two countries out of 46 assessed met the criteria for sporadic transmission, one for clusters of cases, and 43 (93.5%) for community transmission (CT) including three with uncontrolled disease incidence (Eswatini, Namibia and South Africa). Health system response's capacities were assessed as adequate in two countries (4.3%), moderate in 13 countries (28.3%) and limited in 31 countries (64.4%). The risk level, calculated as a combination of transmission classification and health system response's capacities, was assessed at level 0 in one country (2.1%), level 1 in two countries (4.3%), level 2 in 11 countries (23.9%) and level 3 in 32 (69.6%) countries. The scale of severity ranged from 0 to 4, with 0 the lowest. CT coupled with limited response capacity resulted in a level 3 risk assessment in most countries. Countries at level 3 should be considered as priority focus for additional assistance, in order to prevent the risk rising to level 4, which may necessitate enforcing hard and costly lockdown measures. The large number of countries at level 3 indicates the need for an effective risk management system to be used as a basis for adjusting PHSM at national and sub-national levels.


Asunto(s)
COVID-19/epidemiología , Toma de Decisiones , SARS-CoV-2 , Organización Mundial de la Salud , África/epidemiología , Atención a la Salud , Humanos , Administración en Salud Pública , Medición de Riesgo
14.
Epidemiol Infect ; 149: e261, 2021 05 14.
Artículo en Inglés | MEDLINE | ID: mdl-33985609

RESUMEN

Epidemic intelligence activities are undertaken by the WHO Regional Office for Africa to support member states in early detection and response to outbreaks to prevent the international spread of diseases. We reviewed epidemic intelligence activities conducted by the organisation from 2017 to 2020, processes used, key results and how lessons learned can be used to strengthen preparedness, early detection and rapid response to outbreaks that may constitute a public health event of international concern. A total of 415 outbreaks were detected and notified to WHO, using both indicator-based and event-based surveillance. Media monitoring contributed to the initial detection of a quarter of all events reported. The most frequent outbreaks detected were vaccine-preventable diseases, followed by food-and-water-borne diseases, vector-borne diseases and viral haemorrhagic fevers. Rapid risk assessments generated evidence and provided the basis for WHO to trigger operational processes to provide rapid support to member states to respond to outbreaks with a potential for international spread. This is crucial in assisting member states in their obligations under the International Health Regulations (IHR) (2005). Member states in the region require scaled-up support, particularly in preventing recurrent outbreaks of infectious diseases and enhancing their event-based surveillance capacities with automated tools and processes.


Asunto(s)
Epidemias/prevención & control , Vigilancia en Salud Pública/métodos , Organización Mundial de la Salud/organización & administración , África/epidemiología , Control de Enfermedades Transmisibles , Enfermedades Transmisibles/epidemiología , Brotes de Enfermedades/prevención & control , Brotes de Enfermedades/estadística & datos numéricos , Salud Global , Humanos , Medición de Riesgo
15.
Epidemiol Infect ; 149: e98, 2021 04 14.
Artículo en Inglés | MEDLINE | ID: mdl-33849676

RESUMEN

Monitoring and evaluation (M&E) is an essential component of public health emergency response. In the WHO African region (WHO AFRO), over 100 events are detected and responded to annually. Here we discuss the development of the M&E for COVID-19 that established a set of regional and country indicators for tracking the COVID-19 pandemic and response measures. An interdisciplinary task force used the 11 pillars of strategic preparedness and response to define a set of inputs, outputs, outcomes and impact indicators that were used to closely monitor and evaluate progress in the evolving COVID-19 response, with each pillar tailored to specific country needs. M&E data were submitted electronically and informed country profiles, detailed epidemiological reports, and situation reports. Further, 10 selected key performance indicators were tracked to monitor country progress through a bi-weekly progress scoring tool used to identify priority countries in need of additional support from WHO AFRO. Investment in M&E of health emergencies should be an integral part of efforts to strengthen national, regional and global capacities for early detection and response to threats to public health security. The development of an adaptable M&E framework for health emergencies must draw from the lessons learned throughout the COVID-19 response.


Asunto(s)
COVID-19/prevención & control , Organización Mundial de la Salud/organización & administración , África/epidemiología , COVID-19/epidemiología , Urgencias Médicas , Humanos , Vigilancia en Salud Pública , Regionalización , SARS-CoV-2
16.
PLoS One ; 16(2): e0245457, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33630890

RESUMEN

BACKGROUND: The WHO African region frequently experiences outbreaks and epidemics of infectious diseases often exacerbated by weak health systems and infrastructure, late detection, and ineffective outbreak response. To address this, the WHO Regional Office for Africa developed and began implementing the Integrated Disease Surveillance and Response strategy in 1998. OBJECTIVES: This systematic review aims to document the identified successes and challenges surrounding the implementation of IDSR in the region available in published literature to highlight areas for prioritization, further research, and to inform further strengthening of IDSR implementation. METHODS: A systematic review of peer-reviewed literature published in English and French from 1 July 2012 to 13 November 2019 was conducted using PubMed and Web of Science. Included articles focused on the WHO African region and discussed the use of IDSR strategies and implementation, assessment of IDSR strategies, or surveillance of diseases covered in the IDSR framework. Data were analyzed descriptively using Microsoft Excel and Tableau Desktop 2019. RESULTS: The number of peer-reviewed articles discussing IDSR remained low, with 47 included articles focused on 17 countries and regional level systems. Most commonly discussed topics were data reporting (n = 39) and challenges with IDSR implementation (n = 38). Barriers to effective implementation were identified across all IDSR core and support functions assessed in this review: priority disease detection; data reporting, management, and analysis; information dissemination; laboratory functionality; and staff training. Successful implementation was noted where existing surveillance systems and infrastructure were utilized and streamlined with efforts to increase access to healthcare. CONCLUSIONS AND IMPLICATIONS OF FINDINGS: These findings highlighted areas where IDSR is performing well and where implementation remains weak. While challenges related to IDSR implementation since the first edition of the technical guidelines were released are not novel, adequately addressing them requires sustained investments in stronger national public health capabilities, infrastructure, and surveillance processes.


Asunto(s)
Enfermedades Transmisibles/epidemiología , Brotes de Enfermedades/prevención & control , Vigilancia en Salud Pública , África/epidemiología , Humanos
18.
PLoS Negl Trop Dis ; 14(7): e0008417, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32628666

RESUMEN

BACKGROUND: Schistosomiasis is responsible for the second highest burden of disease among neglected tropical diseases globally, with over 90 percent of cases occurring in African regions where drugs to treat the disease are only sporadically available. Additionally, human re-infection after treatment can be a problem where there are high numbers of infected snails in the environment. Recent experiments indicate that aquatic factors, including plants, nutrients, or predators, can influence snail abundance and parasite production within infected snails, both components of human risk. This study investigated how snail host abundance and release of cercariae (the free swimming stage infective to humans) varies at water access sites in an endemic region in Senegal, a setting where human schistosomiasis prevalence is among the highest globally. METHODS/PRINCIPAL FINDINGS: We collected snail intermediate hosts at 15 random points stratified by three habitat types at 36 water access sites, and counted cercarial production by each snail after transfer to the laboratory on the same day. We found that aquatic vegetation was positively associated with per-capita cercarial release by snails, probably because macrophytes harbor periphyton resources that snails feed upon, and well-fed snails tend to produce more parasites. In contrast, the abundance of aquatic macroinvertebrate snail predators was negatively associated with per-capita cercarial release by snails, probably because of several potential sublethal effects on snails or snail infection, despite a positive association between snail predators and total snail numbers at a site, possibly due to shared habitat usage or prey tracking by the predators. Thus, complex bottom-up and top-down ecological effects in this region plausibly influence the snail shedding rate and thus, total local density of schistosome cercariae. CONCLUSIONS/SIGNIFICANCE: Our study suggests that aquatic macrophytes and snail predators can influence per-capita cercarial production and total abundance of snails. Thus, snail control efforts might benefit by targeting specific snail habitats where parasite production is greatest. In conclusion, a better understanding of top-down and bottom-up ecological factors that regulate densities of cercarial release by snails, rather than solely snail densities or snail infection prevalence, might facilitate improved schistosomiasis control.


Asunto(s)
Plantas , Schistosoma/fisiología , Esquistosomiasis/epidemiología , Caracoles/parasitología , Animales , Cercarias/fisiología , Ecosistema , Humanos , Perifiton , Esquistosomiasis/transmisión , Senegal
19.
J R Soc Interface ; 16(159): 20190383, 2019 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-31640501

RESUMEN

The bay scallop Argopecten irradians (Mollusca: Bivalvia) has dozens of iridescent blue eyes that focus light using mirror-based optics. Here, we test the hypothesis that these eyes appear blue because of photonic nanostructures that preferentially scatter short-wavelength light. Using transmission electron microscopy, we found that the epithelial cells covering the eyes of A. irradians have three distinct layers: an outer layer of microvilli, a middle layer of random close-packed nanospheres and an inner layer of pigment granules. The nanospheres are approximately 180 nm in diameter and consist of electron-dense cores approximately 140 nm in diameter surrounded by less electron-dense shells 20 nm thick. They are packed at a volume density of approximately 60% and energy-dispersive X-ray spectroscopy indicates that they are not mineralized. Optical modelling revealed that the nanospheres are an ideal size for producing angle-weighted scattering that is bright and blue. A comparative perspective supports our hypothesis: epithelial cells from the black eyes of the sea scallop Placopecten magellanicus have an outer layer of microvilli and an inner layer of pigment granules but lack a layer of nanospheres between them. We speculate that light-scattering nanospheres help to prevent UV wavelengths from damaging the internal structures of the eyes of A. irradians and other blue-eyed scallops.


Asunto(s)
Células Epiteliales , Ojo , Nanosferas , Pectinidae , Pigmentación/fisiología , Animales , Células Epiteliales/metabolismo , Células Epiteliales/ultraestructura , Ojo/metabolismo , Ojo/ultraestructura , Nanosferas/metabolismo , Nanosferas/ultraestructura , Pectinidae/metabolismo , Pectinidae/ultraestructura
20.
Neurotoxicology ; 73: 183-187, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30974132

RESUMEN

Seizures are a recognized and potentially serious complication of recreational drug use. This study examined a large international data set of presentations to Emergency Departments with acute recreational drug toxicity, the European Drug Emergencies Plus (Euro-DEN Plus) Network, to compare presentations with and without seizures and estimate incidence and associated drugs. Amongst 23,947 presentations between January 2014 and December 2017, there were 1013 (4.2%) with reported seizures. Clinical and demographic features were similar between individuals who had a seizure and those who did not, although rates of coma, cardiac arrest, intubation, intensive care admission, and death were significantly higher in those with seizures. There was a significant association between specific drugs and a higher seizure incidence, including fentanyl (odds ratio 2.63, 95% confidence interval 1.20-5.80), and synthetic cannabinoids (OR 2.90, 95% CI 2.19-3.84). Other drugs were associated with a lower seizure incidence, including heroin (OR 0.46, 95% CI 0.35-0.61), clonazepam (OR 0.22, 95% CI 0.06-0.91), and cannabis (OR 0.65, 95% CI 0.50-0.86). This substantiates observations that the synthetic cannabinoids as a group of novel psychoactive substances are clinically different in consequence of intoxication than cannabis, and that individuals who suffer a seizure in the context of recreational drug intoxication are likely to have worse outcomes overall. Utilising this information of what substances have a greater risk of seizures, could provide tailored harm reduction and education strategies to users to reduce the risk of seizures and their associated complications.


Asunto(s)
Drogas Ilícitas/efectos adversos , Psicotrópicos/efectos adversos , Convulsiones/inducido químicamente , Convulsiones/epidemiología , Trastornos Relacionados con Sustancias/epidemiología , Adulto , Temperatura Corporal/efectos de los fármacos , Cannabinoides/efectos adversos , Cannabinoides/síntesis química , Europa (Continente)/epidemiología , Femenino , Hemodinámica/efectos de los fármacos , Humanos , Drogas Ilícitas/síntesis química , Incidencia , Masculino , Antagonistas de Narcóticos/efectos adversos , Trastornos Relacionados con Opioides/epidemiología , Pronóstico , Psicotrópicos/síntesis química , Respiración/efectos de los fármacos , Medición de Riesgo , Factores de Riesgo , Convulsiones/diagnóstico , Convulsiones/fisiopatología , Trastornos Relacionados con Sustancias/diagnóstico , Trastornos Relacionados con Sustancias/fisiopatología
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