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1.
NMR Biomed ; 35(5): e4667, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34964179

RESUMEN

Cardiac electrophysiology and cardiac mechanics both depend on the average cardiomyocyte long-axis orientation. In the realm of personalized medicine, knowledge of the patient-specific changes in cardiac microstructure plays a crucial role. Patient-specific computational modelling has emerged as a tool to better understand disease progression. In vivo cardiac diffusion tensor imaging (cDTI) is a vital tool to non-destructively measure the average cardiomyocyte long-axis orientation in the heart. However, cDTI suffers from long scan times, rendering volumetric, high-resolution acquisitions challenging. Consequently, interpolation techniques are needed to populate bio-mechanical models with patient-specific average cardiomyocyte long-axis orientations. In this work, we compare five interpolation techniques applied to in vivo and ex vivo porcine input data. We compare two tensor interpolation approaches, one rule-based approximation, and two data-driven, low-rank models. We demonstrate the advantage of tensor interpolation techniques, resulting in lower interpolation errors than do low-rank models and rule-based methods adapted to cDTI data. In an ex vivo comparison, we study the influence of three imaging parameters that can be traded off against acquisition time: in-plane resolution, signal to noise ratio, and number of acquired short-axis imaging slices.


Asunto(s)
Imagen de Difusión Tensora , Miocitos Cardíacos , Animales , Imagen de Difusión Tensora/métodos , Humanos , Relación Señal-Ruido , Porcinos
2.
Magn Reson Med ; 86(1): 277-292, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33619807

RESUMEN

PURPOSE: Myofiber strain, Eff , is a mechanistically relevant metric of cardiac cell shortening and is expected to be spatially uniform in healthy populations, making it a prime candidate for the evaluation of local cardiomyocyte contractility. In this study, a new, efficient pipeline was proposed to combine microstructural cDTI and functional DENSE data in order to estimate Eff in vivo. METHODS: Thirty healthy volunteers were scanned with three long-axis (LA) and three short-axis (SA) DENSE slices using 2D displacement encoding and one SA slice of cDTI. The total acquisition time was 11 minutes ± 3 minutes across volunteers. The pipeline first generates 3D SA displacements from all DENSE slices which are then combined with cDTI data to generate a cine of myofiber orientations and compute Eff . The precision of the post-processing pipeline was assessed using a computational phantom study. Transmural myofiber strain was compared to circumferential strain, Ecc , in healthy volunteers using a Wilcoxon sign rank test. RESULTS: In vivo, computed Eff was found uniform transmurally compared to Ecc (-0.14[-0.15, -0.12] vs -0.18 [-0.20, -0.16], P < .001, -0.14 [-0.16, -0.12] vs -0.16 [-0.17, -0.13], P < .001 and -0.14 [-0.16, -0.12] vs Ecc_C = -0.14 [-0.15, -0.11], P = .002, Eff_C vs Ecc_C in the endo, mid, and epi layers, respectively). CONCLUSION: We demonstrate that it is possible to measure in vivo myofiber strain in a healthy human population in 10 minutes per subject. Myofiber strain was observed to be spatially uniform in healthy volunteers making it a potential biomarker for the evaluation of local cardiomyocyte contractility in assessing cardiovascular dysfunction.


Asunto(s)
Imagen por Resonancia Cinemagnética , Miocitos Cardíacos , Voluntarios Sanos , Humanos , Fantasmas de Imagen
3.
BMC Public Health ; 20(1): 1233, 2020 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-32787813

RESUMEN

BACKGROUND: Control and elimination of onchocerciasis requires regular follow-up and evaluation of community directed treatment with ivermectin (CDTi) program implementation. This research was aimed to assess the epidemiological status of onchocerciasis in disease endemic communities of Asosa and Yeki districts of Ethiopia after 5 and 15 years of successive CDTi respectively, and to evaluate the decline in infection and morbidity burden. METHODS: A community-based cross-sectional study was conducted from August 2017 to January 2018 (i.e. within 2-7 months since the last treatment) using interview, physical and parasitological examinations. Pre-CDTi epidemiological data were obtained from studies conducted prior to the launch of CDTi. RESULTS: A total of 3002 individuals (1567 from Asosa and 1435 from Yeki) were included. No infection was detected from Yeki. In Asosa, the prevalence of infection was 1.6%. The geometric mean intensity of infection was 0.02 mf/mg of skin snip. The prevalence rates of dermatitis, depigmentation, nodule, and atrophy in Yeki were 33(2.3%), 57(4%), 37(2.6%) and 11(0.7%), respectively. The prevalence rates of papular dermatitis, depigmentation, palpable nodule, atrophy, and blindness in Asosa were 94(6%), 38(2.4%), 30(1.9%), 28(1.8%) and 2(0.1%), respectively. Five years of CDTi had significantly reduced prevalence and intensity of infection by 91.8% (p < 0.001) and 99.7% (p < 0.001), respectively. Moreover, CDTi reduced prevalence of papular dermatitis by 95.9% (p < 0.001), palpable nodule by 90.5% (p < 0.001), and atrophy by 30% (p = 0.6) in Yeki. Similarly, CDTi reduced prevalence of papular dermatitis by 88.6% (p < 0.001), depigmentation by 90.3% (p < 0.001), atrophy by 89.5% (p < 0.001), and blindness by 90% (p < 0.001) in Asosa. CONCLUSIONS: Fifteen years of successive CDTi had brought the infection from high to zero in Yeki. However, thorough entomological and serological data need to be generated to ascertain whether complete interruption of parasite transmission has been attained, and for considerations of an evidence-based CDTi cessation. Five years of CDTi in Asosa has significantly reduced the infection and morbidity of onchocerciasis to very low level. We, hereby, recommend biannual CDTi to continue in Asosa and its surroundings until the infection transmission is fully interrupted.


Asunto(s)
Enfermedades Endémicas/prevención & control , Ivermectina/uso terapéutico , Administración Masiva de Medicamentos , Oncocercosis/tratamiento farmacológico , Oncocercosis/epidemiología , Adolescente , Adulto , Estudios Transversales , Etiopía/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Morbilidad , Prevalencia , Evaluación de Programas y Proyectos de Salud , Adulto Joven
4.
Sensors (Basel) ; 20(1)2020 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-31947913

RESUMEN

A new methodology is presented using well known electrical characterization techniques on dedicated single devices in order to investigate backside interface contribution to the measured pixel dark current in BSI CMOS image sensors technologies. Extractions of interface states and charges within the dielectric densities are achieved. The results show that, in our case, the density of state is not directly the source of dark current excursions. The quality of the passivation of the backside interface appears to be the key factor. Thanks to the presented new test structures, it has been demonstrated that the backside interface contribution to dark current can be investigated separately from other sources of dark current, such as the frontside interface, DTI (deep trench isolation), etc.

5.
Parasite Epidemiol Control ; 25: e00343, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38405181

RESUMEN

Background: Loiasis is an endemic filarial infection in the rainforest zone of West and Central Africa. Repeated annual community-directed treatment with ivermectin (CDTI) delivered for several years to control onchocerciasis has been shown to reduce the prevalence and intensity of Loiasis in some Loa loa-Onchocerca volvulus co-endemic areas. However, the impact of these multiple rounds of CDTI on entomological indicators of loiasis transmission is not known, and was therefore assessed in this study in areas with contrasting histories of CDTI. Methods: The study was conducted in the East, North-west and South-west 1 CDTI project sites of Cameroon. Two communities per CDTI project were selected for fly collection and dissection. Ivermectin treatment coverage was documented in these areas, and this was correlated to Chrysops infection and infective rates. A total of 7029 female Chrysops were collected from 6 communities of the 3 CDTI projects (East, North-west, and South-west 1) and from 2 communities in a non-CDTI district (East). Results: Chrysops biting densities and parous rates were significantly reduced in the North-west and South-west sites post-CDTI, while in the East, biting densities were similar in non-CDTI and CDTI sites, with higher parous rates observed in the non-CDTI site. Infection and infective rates in the East non-CDTI site were 4.4% and 1.8% respectively, as compared to 3.3% and 1.3% in the CDTI site after 10 ivermectin rounds (there were no baseline data for the latter). In the North-west site, significant reductions in Chrysops infection and infective rates from 10.2% and 4.2% respectively, to 3.5% and 1.2 (after 9 rounds of ivermectin treatment), were recorded following CDTI. In the South-west, infection rate significantly increased from 1.74% to 2.8% and infective rate remained statistically unchanged after 14 rounds of CDTI (0.45% - 0.40%). Similar trends in Mean Head L3 were observed except in the East site where this indicator was similar in both CDTI and control sites. Only in the North-west site did monthly transmission potentials decrease significantly. Conclusion: This study demonstrated that the impact of repeated annual treatment with ivermectin for the control of onchocerciasis using community directed delivery approach on the entomological indicators of loiasis varies with bioecological zones. Community directed treatment with ivermectin induced a significant reduction in the entomological indicators of loiasis in the North-West project site which lies in forest savanna area. A non-significant decrease was observed in the East project site and in contrast, a significant increase was observed in the South-West 1 project site which both lies in the rainforest zones.

6.
Ann Afr Med ; 22(3): 252-258, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37417010

RESUMEN

Purpose: To assess community-directed treatment coverage with Ivermectin (CDTI) in Onchocerciasis-endemic communities in Birnin Kudu local government area (LGA) Jigawa state. Subjects and Methods: This was a community-based multistaged cross-sectional survey based on probability proportional to size. The study involved the administration of a questionnaire on 2021 respondents from 207 households. Also, 30 Community Leaders and Community Directed Distributors (CDDs) were purposively selected for interview from the communities visited. Results: Overall, 2021 respondents from the 2031 sampled population took part in the study giving a response rate of 99.6%. Slightly above half, 1130 (55.9%) were males. The geographic and therapeutic coverage of mass drug administration of Ivermectin achieved in the LGA was 100% and 79.9%, respectively. The key factors affecting coverage includes the unavailability of drugs (48.8%), absenteeism of some of the household members (31%), and inadequate incentives to the CDDs by the government and poor record keeping by the CDDs. Conclusion: This study found that the minimum geographic and therapeutic coverage of Ivermectin distribution was achieved by CDD as recommended by the World Health Organization for the control of onchocerciasis. For this to be sustained and to achieve elimination, there must be an adequate supply of ivermectin, training of CDDs, retraining of CDDs, adequate supervision in record keeping, and health education to the community.


Résumé Objectif: Évaluer la couverture du traitement sous direction communautaire à l'ivermectine (TIDC) dans les communautés endémiques de l'onchocercose de la zone d'administration locale de Birnin Kudu (LGA) dans l'État de Jigawa. Sujets et méthodes: Il s'agissait d'une enquête transversale communautaire à plusieurs degrés basée sur une probabilité proportionnelle à la taille. L'étude a impliqué l'administration d'un questionnaire sur 2021 répondants de 207 ménages. De plus, 30 leaders communautaires et distributeurs dirigés par la communauté (CDD) ont été délibérément sélectionnés pour un entretien dans les communautés visitées. Résultats: Globalement, 2021 répondants sur la population échantillonnée de 2031 ont participé à l'étude, soit un taux de réponse de 99,6 %. Un peu plus de la moitié, 1130 (55,9 %) étaient des hommes. La couverture géographique et thérapeutique de l'administration massive d'ivermectine obtenue dans la LGA était de 100 % et de 79,9 %, respectivement. Les principaux facteurs affectant la couverture comprennent l'indisponibilité des médicaments (48,8%), l'absentéisme de certains membres du ménage (31%), et les incitations inadéquates aux DC par le gouvernement et la mauvaise tenue des dossiers par les DC. Conclusion: Cette étude a révélé que la couverture géographique et thérapeutique minimale de la distribution d'ivermectine était atteinte par le CDD tel que recommandé par l'Organisation mondiale de la santé pour le contrôle de l'onchocercose. Pour que cela soit durable et pour parvenir à l'élimination, il doit y avoir un approvisionnement adéquat en ivermectine, une formation des DC, un recyclage des DC, une supervision adéquate de la tenue des dossiers et une éducation sanitaire de la communauté. Mots-clés: Distributeurs communautaires, TIDC, ivermectine, onchocercose.


Asunto(s)
Ivermectina , Oncocercosis , Masculino , Humanos , Femenino , Ivermectina/uso terapéutico , Oncocercosis/tratamiento farmacológico , Oncocercosis/epidemiología , Gobierno Local , Nigeria/epidemiología , Estudios Transversales , Servicios de Salud Comunitaria
7.
Front Physiol ; 14: 1171201, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36935739

RESUMEN

[This corrects the article DOI: 10.3389/fphys.2022.1042537.].

8.
Acta Trop ; 225: 106218, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34755644

RESUMEN

Community-Directed Treatment with Ivermectin (CDTI) is the strategy of choice to fight onchocerciasis in Africa. In areas where loiasis is endemic, onchocerciasis control and/or elimination is hindered by severe adverse events (SAEs) occurring after ivermectin mass treatments. This study aimed at (i) investigating the impact of two decades of CDTI on L. loa clinical and parasitological indicators in the Ndikinimeki Health District, and (ii) assessing the risk of SAEs after this long-term preventive chemotherapy. A cluster-based cross-sectional survey was conducted in the six Health Areas of the Ndikinimeki Health District. All volunteers underwent day-time calibrated thick blood smears to search for L. loa microfilariae, as well as an interview to assess the history of migration of eye worm and Calabar swelling. The overall prevalence of L. loa microfilaraemia was 2.2 % (95% CI: 1.3-3.7%), and the proportions of individuals who had already experienced eye worm and/or Calabar swelling were 1.0% and 0.5%, respectively. The mean microfilarial density was 63.55 (SD: 559.17; maximum: 9220.0) mf/mL. These findings indicate that (i) the long-term ivermectin-based preventive chemotherapy against onchocerciasis significantly reduced L. loa clinical and parasitological indicators, and (ii) the risk of developing neurologic and potentially fatal SAE after ivermectin mass treatment is zero in the Ndikinimeki Health District.


Asunto(s)
Loiasis , Oncocercosis , Animales , Camerún/epidemiología , Estudios Transversales , Enfermedades Endémicas/prevención & control , Humanos , Ivermectina , Loa , Loiasis/tratamiento farmacológico , Loiasis/epidemiología , Loiasis/prevención & control , Oncocercosis/tratamiento farmacológico , Oncocercosis/epidemiología , Oncocercosis/prevención & control , Prevalencia
9.
Appl Sci (Basel) ; 12(7)2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36032414

RESUMEN

In vivo cardiac diffusion tensor imaging (cDTI) data were acquired in swine subjects six to ten weeks post-myocardial infarction (MI) to identify microstructural-based biomarkers of MI. Diffusion tensor invariants, diffusion tensor eigenvalues, and radial diffusivity (RD) are evaluated in the infarct, border, and remote myocardium, and compared with extracellular volume fraction (ECV) and native T1 values. Additionally, to aid the interpretation of the experimental results, the diffusion of water molecules was numerically simulated as a function of ECV. Finally, findings based on in vivo measures were confirmed using higher-resolution and higher signal-to-noise data acquired ex vivo in the same subjects. Mean diffusivity, diffusion tensor eigenvalues, and RD increased in the infarct and border regions compared to remote myocardium, while fractional anisotropy decreased. Secondary (e2) and tertiary (e3) eigenvalues increased more significantly than the primary eigenvalue in the infarct and border regions. These findings were confirmed by the diffusion simulations. Although ECV presented the largest increase in infarct and border regions, e2, e3, and RD increased the most among non-contrast-based biomarkers. RD is of special interest as it summarizes the changes occurring in the radial direction and may be more robust than e2 or e3 alone.

10.
Front Physiol ; 13: 1042537, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36518106

RESUMEN

Simulations of cardiac electrophysiology and mechanics have been reported to be sensitive to the microstructural anisotropy of the myocardium. Consequently, a personalized representation of cardiac microstructure is a crucial component of accurate, personalized cardiac biomechanical models. In-vivo cardiac Diffusion Tensor Imaging (cDTI) is a non-invasive magnetic resonance imaging technique capable of probing the heart's microstructure. Being a rather novel technique, issues such as low resolution, signal-to noise ratio, and spatial coverage are currently limiting factors. We outline four interpolation techniques with varying degrees of data fidelity, different amounts of smoothing strength, and varying representation error to bridge the gap between the sparse in-vivo data and the model, requiring a 3D representation of microstructure across the myocardium. We provide a workflow to incorporate in-vivo myofiber orientation into a left ventricular model and demonstrate that personalized modelling based on fiber orientations from in-vivo cDTI data is feasible. The interpolation error is correlated with a trend in personalized parameters and simulated physiological parameters, strains, and ventricular twist. This trend in simulation results is consistent across material parameter settings and therefore corresponds to a bias introduced by the interpolation method. This study suggests that using a tensor interpolation approach to personalize microstructure with in-vivo cDTI data, reduces the fiber uncertainty and thereby the bias in the simulation results.

11.
Parasite Epidemiol Control ; 16: e00235, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35024476

RESUMEN

INTRODUCTION: Achieving high Mass Drug Administration (MDA) coverage and drug uptake are pivotal in the efforts to eradicate onchocerciasis. The present study investigated the extent and predictors of ivermectin MDA coverage and uptake from the individual and healthcare providers' perspectives. The extent of ivermectin distribution and uptake, and the predictors of distribution and uptake were investigated in endemic communities in the Ashanti Region of Ghana. METHODS: A cross-sectional survey was conducted from August to October 2019 in communities within the Atwima Nwabiagya North District. A total of 2008 respondents were interviewed. Data was collected with REDCap mobile App which had an electronic version of the structured questionnaire. Descriptive data was presented in frequency tables, and bivariate and multivariate logistics regression analysis were performed to measure the associations between exposure variables and outcome variables which were received and uptake of MDA drugs. RESULTS: A total of 1284 (63.9%) respondents did not receive ivermectin during the 2019 MDA programme and more than half of them were not aware of the drug distribution (53.3%). The most common reasons for not ingesting the drug were fear of side effects (47.7%) and not trusting the drug distributors (20.0%). Respondents in the age group 48-57 years (AOR = 1.37; 95%CI: 1.01-2.67), Persons in the high wealth index (AOR = 1.40; 95%CI: 1.11-1.77), Being aware of the MDA programme (AOR = 6.67: 95%CI: 4.76-9.35), MDA being beneficial (AOR = 2.12; 95%CI: 1.54-2.92) participating in previous MDA (AOR = 5.44; 95%CI: 4.25-6.98) and having stayed in the communities for 10 years and above significantly increased the odds of receiving MDA drugs. Previous uptake of MDA drugs (AOR = 10.58; 95%CI: 5.78-19.38) and perception of the MDA drug as beneficial (AOR = 5.25; 95%CI: 2.55-10.82) increased the likelihood of ingesting drugs when received. CONCLUSION: The main health system challenge was limited awareness creation regarding MDA. This seems to affect the optimal utilization of the ivermectin MDA intervention. MDA programmes against onchocerciasis eradication should be designed taking into account specific contextual factors to improve implementation outcomes.

12.
Pathogens ; 9(12)2020 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-33322724

RESUMEN

Ivermectin (IVM) is a broad spectrum endectocide whose initial indication was onchocerciasis. Although loiasis is not among its indications, IVM also exhibits antiparasitic activity against Loa loa. IVM-based preventive chemotherapies (PCs), so-called community-directed treatment with ivermectin (CDTI), have led to the interruption of transmission of onchocerciasis in some foci. A cross-sectional study was conducted in the Yabassi Health District where CDTI have been implemented since 20 years to fight onchocerciasis. All volunteers aged ≥ 5 years underwent daytime calibrated thick blood smears to search for L. loa microfilariae (mf). The prevalence of loiasis was 3.7% (95% CI: 2.2-6.2), significantly lower than its baseline prevalence (12.4%; 95% CI: 10.1-15.2; Chi-Square = 21.4; df = 1; p < 0.0001). Similarly, the microfilarial density was significantly low (mean = 1.8 mf/mL; SD = 13.6; max = 73,600) compared to baseline microfilarial density (mean = 839.3 mf/mL; SD = 6447.1; max = 130,840; Wilcoxon W = 179,904.5; p < 0.0001). This study revealed that the endemicity level of loiasis was significantly low compared to its baseline value, indicating a significant impact of IVM-based PC on this filarial disease. However, transmission is still ongoing, and heavily infected individuals are still found in communities, supporting why some individuals are still experiencing severe adverse events despite > 2 decades of CDTI in this Health District.

13.
Parasit Vectors ; 13(1): 519, 2020 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-33066826

RESUMEN

BACKGROUND: Ivermectin-based preventive chemotherapy (PC) is distributed annually to all at-risk populations eligible for ivermectin treatment to control and/or eliminate onchocerciasis. Information on the impact of mass ivermectin administration on onchocerciasis transmission is scanty, and it is tricky to appreciate the progress towards elimination and engage corrective measures. To fill that gap in the Centre Region in Cameroon, the current onchocerciasis endemicity level in the Ndikinimeki Health District after about two decades of mass treatments was assessed. METHODS: A cluster-based cross-sectional survey was carried out in the Ndikinimeki Health District and all volunteers aged ≥ 5 years were (i) interviewed on their compliance to ivermectin over the past five years and (ii) underwent clinical (nodule palpation and visual search for onchocercal lesions) and parasitological examinations (skin snip) for onchocerciasis. RESULTS: The overall Onchocerca volvulus prevalence was 7.0% (95% CI: 5.2-9.3%). The prevalence of the disease was significantly higher in the communities Kiboum 1 and Kiboum 2 compared to the other communities (highest prevalence in Makénéné Town Water: 8.5%; 95% CI: 2.3-20.4%) (χ2 = 51.314, df = 11, P = 0.0001). The proportion of systematic non-compliers to ivermectin was 23.3% (95% CI: 19.9-27.1%) among individuals interviewed. In the sentinel sites (Kiboum communities), onchocerciasis prevalence decreased from 95.2% (95% CI: 88.3-98.1%) to 23.7% (95% CI: 14.7-36.0%). CONCLUSIONS: This study has revealed that the Ndikinimeki Health District is hypo-endemic for onchocerciasis after about two decades of preventive chemotherapy. However, transmission is ongoing, with potential hotspots in the Kiboum 1 and Kiboum 2 communities, which are known as first-line communities (closest to the breeding sites of the vector). Alternative or complementary strategies to annual ivermectin appear compulsory to accelerate the momentum towards onchocerciasis elimination.


Asunto(s)
Antiparasitarios/administración & dosificación , Ivermectina/administración & dosificación , Onchocerca volvulus/fisiología , Oncocercosis/epidemiología , Adolescente , Adulto , Animales , Camerún/epidemiología , Niño , Preescolar , Estudios Transversales , Enfermedades Endémicas , Femenino , Humanos , Masculino , Administración Masiva de Medicamentos , Persona de Mediana Edad , Oncocercosis/parasitología , Oncocercosis/transmisión , Prevalencia , Adulto Joven
14.
Acta Trop ; 181: 50-59, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29410302

RESUMEN

The Mahenge Mountains onchocerciasis focus in south eastern Tanzania was historically one of the most heavily infected areas in the country. The vectors of Onchocerca volvulus are mainly Simulium damnosum complex blackflies, but a species of the Simulium neavei group may also contribute to transmission in some areas. The only detailed studies of parasite transmission in Mahenge were conducted in the late 1960s. The taxonomy of the S. damnosum complex has since been revised and onchocerciasis control through annual community directed treatment with ivermectin (CDTI) commenced in 1997. This study aimed to provide a cytogenetic and molecular update of the S. damnosum complex cytoforms present in Mahenge, and to evaluate the current status of O. volvulus transmission by blackflies following 19 years of annual CDTI. Rivers were surveyed to identify sites of S. damnosum s.l. breeding among the eastern slopes of the mountains, and human landing collections of adult female blackflies were made close to breeding sites. Identification of S. damnosum complex cytoforms was by cytotaxonomy of late-instar larvae and ITS1 amplicon size polymorphisms of larvae and adults. Adult blackflies were pool screened for O. volvulus infection using a triplex real-time PCR. The cytoforms 'Nkusi', Simulium kilibanum and 'Turiani' were found breeding in perennial rivers. 'Nkusi' and S. kilibanum were collected on human bait at 7/7 catch sites and possessed ITS1 profiles most closely resembling the molecular forms 'Nkusi J' and S. kilibanum 'T'. Whereas 'Turiani' was present in rivers, it was not collected on human bait and appears to be zoophilic. Simulium nyasalandicum was collected in low numbers on human bait at 3/7 catch sites. In total, 12,452 S. damnosum s.l. were pool screened and O. volvulus infection was detected in 97/104 pools of bodies and 51/104 pools of heads. The estimated percentage of S. damnosum s.l. carrying infective L3 stage parasites was 0.57% (95% CI 0.43%-0.74%). Onchocerca volvulus transmission by S. damnosum s.l. is continuing in the Mahenge Mountains after 19 years of annual CDTI. Infection rates appear similar to those reported in the 1960s, but a more detailed study is required to fully understand the epidemiological significance of the ongoing transmission. These results provide further evidence that annual CDTI may be insufficient to eliminate the parasite in formerly hyperendemic foci.


Asunto(s)
Insectos Vectores/parasitología , Onchocerca volvulus/aislamiento & purificación , Oncocercosis/transmisión , Simuliidae/parasitología , Adulto , Animales , Cruzamiento , Femenino , Humanos , Ivermectina/uso terapéutico , Onchocerca volvulus/genética , Oncocercosis/tratamiento farmacológico , Ríos , Tanzanía
15.
Jpn J Infect Dis ; 70(3): 252-257, 2017 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-27580579

RESUMEN

Here, we report a bacterium-isolated as the sole pathogen from a child with diarrhea-harboring eae and 2 different cytolethal distending toxin genes (cdt) that are homologous to Escherichia coli cdt-I and cdt-II. The bacterium was originally identified as atypical E. coli by conventional biochemical testing, but was finally identified as E. albertii by multilocus sequence analysis, which is the only method that can currently differentiate E. albertii from E. coli. The Shiga toxin 2f (stx2f) genes were also detected in the strain. Production of these 3 toxins was confirmed by western blotting and/or a cytotoxicity assay using eukaryotic cell lines. This is the first report showing the biological activity of CDT-I, CDT-II, and Stx2f in E. albertii.


Asunto(s)
Toxinas Bacterianas/análisis , Diarrea/microbiología , Diarrea/patología , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/patología , Escherichia coli/patogenicidad , Factores de Virulencia/análisis , Toxinas Bacterianas/clasificación , Toxinas Bacterianas/genética , Western Blotting , Escherichia coli/clasificación , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Humanos , Lactante , Tipificación de Secuencias Multilocus , Factores de Virulencia/clasificación , Factores de Virulencia/genética
16.
Prog Cardiovasc Dis ; 56(3): 344-55, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24267442

RESUMEN

Recent population studies demonstrate an increasing burden of cardiovascular disease (CVD) and related risk factors in sub-Saharan Africa (SSA). The mitigation or reversal of this trend calls for effective health promotion and preventive interventions. In this article, we review the core principles, challenges, and progress in promoting cardiovascular health with special emphasis on interventions to address physical inactivity, poor diet, tobacco use, and adverse cardiometabolic risk factor trends in SSA. We focus on the five essential strategies of the Ottawa Charter for Health Promotion. Successes highlighted include community-based interventions in Ghana, Nigeria, South Africa, and Mauritius and school-based programs in Kenya, Namibia, and Swaziland. We address the major challenge of developing integrated interventions, and showcase partnerships opportunities. We conclude by calling for intersectoral partnerships for effective and sustainable intervention strategies to advance cardiovascular health promotion and close the implementation gap in accordance with the 2009 Nairobi Call to Action on Health Promotion.


Asunto(s)
Enfermedades Cardiovasculares/prevención & control , Atención a la Salud/organización & administración , Países en Desarrollo , Promoción de la Salud , África del Sur del Sahara/epidemiología , Enfermedades Cardiovasculares/epidemiología , Humanos , Factores de Riesgo
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