Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
Am J Trop Med Hyg ; 108(2): 363-365, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36572007

RESUMEN

Chikungunya virus, a mosquito-borne alphavirus, causes acute febrile illness with polyarthralgia. Groups at risk for severe disease include neonates, people with underlying medical conditions, and those aged ≥ 65 years. Several chikungunya vaccines are in late clinical development with licensure expected in the United States during 2023. We administered a questionnaire to randomly selected households in the U.S. Virgin Islands (USVI) to assess interest in a hypothetical chikungunya vaccine. Estimates were calibrated to age and sex of USVI population, and univariate and multivariable analyses were performed. Of 966 participants, 520 (adjusted 56%, 95% CI = 51-60%) were interested in receiving the vaccine. Of 446 participants not interested in vaccination, 203 (adjusted 47%, 95% CI = 41-52%) cited safety concerns as the reason. Educational efforts addressing vaccine safety concerns and risk factors for severe disease would likely improve vaccine acceptability and uptake among those most at risk.


Asunto(s)
Fiebre Chikungunya , Virus Chikungunya , Culicidae , Vacunas , Animales , Recién Nacido , Humanos , Estados Unidos/epidemiología , Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/prevención & control , Islas Virgenes de los Estados Unidos/epidemiología
2.
PLoS Negl Trop Dis ; 13(7): e0007563, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31323020

RESUMEN

Chikungunya virus (CHIKV), an alphavirus that causes fever and severe polyarthralgia, swept through the Americas in 2014 with almost 2 million suspected or confirmed cases reported by April 2016. In this study, we estimate the direct medical costs, cost of lost wages due to absenteeism, and years lived with disability (YLD) associated with the 2014-2015 CHIKV outbreak in the U.S. Virgin Islands (USVI). For this analysis, we used surveillance data from the USVI Department of Health, medical cost data from three public hospitals in USVI, and data from two studies of laboratory-positive cases up to 12 months post illness. On average, employed case-patients missed 9 days of work in the 12 months following their disease onset, which resulted in an estimated cost of $15.5 million. Estimated direct healthcare costs were $2.9 million for the first 2 months and $0.6 million for 3-12 months following the outbreak. The total estimated cost associated with the outbreak ranged from $14.8 to $33.4 million (approximately 1% of gross domestic product), depending on the proportion of the population infected with symptomatic disease, degree of underreporting, and proportion of cases who were employed. The estimated YLDs associated with long-term sequelae from the CHIKV outbreak in the USVI ranged from 599-1,322. These findings highlight the significant economic burden of the recent CHIKV outbreak in the USVI and will aid policy-makers in making informed decisions about prevention and control measures for inevitable, future CHIKV outbreaks.


Asunto(s)
Fiebre Chikungunya/economía , Brotes de Enfermedades/economía , Adulto , Fiebre Chikungunya/epidemiología , Niño , Costo de Enfermedad , Monitoreo Epidemiológico , Humanos , Islas Virgenes de los Estados Unidos
3.
Am J Trop Med Hyg ; 99(5): 1321-1326, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30226143

RESUMEN

When introduced into a naïve population, chikungunya virus generally spreads rapidly, causing large outbreaks of fever and severe polyarthralgia. We randomly selected households in the U.S. Virgin Islands (USVI) to estimate seroprevalence and symptomatic attack rate for chikungunya virus infection at approximately 1 year following the introduction of the virus. Eligible household members were administered a questionnaire and tested for chikungunya virus antibodies. Estimated proportions were calibrated to age and gender of the population. We enrolled 509 participants. The weighted infection rate was 31% (95% confidence interval [CI]: 26-36%). Among those with evidence of chikungunya virus infection, 72% (95% CI: 65-80%) reported symptomatic illness and 31% (95% CI: 23-38%) reported joint pain at least once per week approximately 1 year following the introduction of the virus to USVI. Comparing rates from infected and noninfected study participants, 70% (95% CI: 62-79%) of fever and polyarthralgia and 23% (95% CI: 9-37%) of continuing joint pain in patients infected with chikungunya virus were due to their infection. Overall, an estimated 43% (95% CI: 33-52%) of the febrile illness and polyarthralgia in the USVI population during the outbreak was attributable to chikungunya virus and only 12% (95% CI: 7-17%) of longer term joint pains were attributed to chikungunya virus. Although the rates of infection, symptomatic disease, and longer term joint symptoms identified in USVI are similar to other outbreaks of the disease, a lower proportion of acute fever and joint pain was found to be attributable to chikungunya virus.


Asunto(s)
Anticuerpos Antivirales/sangre , Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/inmunología , Virus Chikungunya/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Artralgia/epidemiología , Artralgia/virología , Virus Chikungunya/aislamiento & purificación , Niño , Preescolar , Brotes de Enfermedades , Composición Familiar , Femenino , Fiebre/epidemiología , Fiebre/virología , Humanos , Incidencia , Lactante , Masculino , Persona de Mediana Edad , Estudios Seroepidemiológicos , Encuestas y Cuestionarios , Islas Virgenes de los Estados Unidos/epidemiología , Adulto Joven
4.
J Anim Sci ; 96(5): 1590-1599, 2018 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-29635633

RESUMEN

Reliance on anthelmintic drugs to control internal parasites in sheep is no longer sustainable because of the development of resistance to these drugs in parasite populations. Genetic selection may offer an alternative long-term solution, as differences in parasite resistance exist both within and among sheep breeds. However, selection for parasite resistance may have correlated effects on other production traits. The objectives of this study were to estimate genetic parameters for weaning (WFEC) and postweaning (PWFEC) fecal egg counts (FEC) and assess their relationship with birth (BWT), weaning (WWT), and postweaning (PWWT) BW in Katahdin lambs. The study used WFEC (n = 2,537), PWFEC (n = 3.421), BWT (n = 12,869), WWT (n = 10,961), and PWWT (n = 7,812) from 12,869 lambs measured between 2003 and 2015 in 13 flocks enrolled in the U.S. National Sheep Improvement Program. Animal and sire models were fitted to the data using the ASReml statistical package. Records were corrected for fixed effects of dam age, joint effect of type of birth and rearing, and management group (defined by joint effects of flock, sex, and birth year and season); lamb age in days at each measurement time was fitted as a covariate. Maternal additive and maternal permanent environmental effects were not significant (P > 0.05), but litter effects influenced (P < 0.01) both WFEC and PWFEC. Heritability estimates ranged from 0.18 to 0.26 for WFEC and 0.23 to 0.46 for PWFEC, depending on the model used. Heritability estimates from sire models were higher than estimates from animal models. Direct additive, litter, residual, and phenotypic correlations between WFEC and PWFEC were 0.82, 0.25, 0.15, and 0.29, respectively. Bivariate analyses revealed low to moderate correlations between BW and FEC. Moderate heritabilities for FEC in this study indicated that genetic progress for this trait can be achieved in Katahdin lambs and that selection for low FEC should have little or no effect on BW.


Asunto(s)
Antihelmínticos/uso terapéutico , Heces/parasitología , Helmintiasis Animal/parasitología , Helmintos/aislamiento & purificación , Recuento de Huevos de Parásitos/veterinaria , Enfermedades de las Ovejas/parasitología , Animales , Peso Corporal/genética , Cruzamiento , Clima , Femenino , Masculino , Fenotipo , Estaciones del Año , Ovinos , Destete
5.
Theor Biol Med Model ; 14(1): 7, 2017 03 27.
Artículo en Inglés | MEDLINE | ID: mdl-28347332

RESUMEN

BACKGROUND: A deterministic model is developed for the spatial spread of an epidemic disease in a geographical setting. The disease is borne by vectors to susceptible hosts through criss-cross dynamics. The model is focused on an outbreak that arises from a small number of infected hosts imported into a subregion of the geographical setting. The goal is to understand how spatial heterogeneity of the vector and host populations influences the dynamics of the outbreak, in both the geographical spread and the final size of the epidemic. METHODS: Partial differential equations are formulated to describe the spatial interaction of the hosts and vectors. The partial differential equations have reaction-diffusion terms to describe the criss-cross interactions of hosts and vectors. The partial differential equations of the model are analyzed and proven to be well-posed. A local basic reproduction number for the epidemic is analyzed. RESULTS: The epidemic outcomes of the model are correlated to the spatially dependent parameters and initial conditions of the model. The partial differential equations of the model are adapted to seasonality of the vector population, and applied to the 2015-2016 Zika seasonal outbreak in Rio de Janeiro Municipality in Brazil. CONCLUSIONS: The results for the model simulations of the 2015-2016 Zika seasonal outbreak in Rio de Janeiro Municipality indicate that the spatial distribution and final size of the epidemic at the end of the season are strongly dependent on the location and magnitude of local outbreaks at the beginning of the season. The application of the model to the Rio de Janeiro Municipality Zika 2015-2016 outbreak is limited by incompleteness of the epidemic data and by uncertainties in the parametric assumptions of the model.


Asunto(s)
Brotes de Enfermedades , Vectores de Enfermedades , Interacciones Huésped-Patógeno , Modelos Teóricos , Infección por el Virus Zika/epidemiología , Virus Zika , Animales , Brasil/epidemiología , Brotes de Enfermedades/estadística & datos numéricos , Interacciones Huésped-Patógeno/fisiología , Humanos , Estaciones del Año , Virus Zika/fisiología , Infección por el Virus Zika/diagnóstico
6.
In. Caribbean Public Health Agency. Caribbean Public Health Agency: 60th Annual Scientific Meeting. Kingston, The University of the West Indies. Faculty of Medical Sciences, 2015. p.[1-75]. (West Indian Medical Journal Supplement).
Monografía en Inglés | MedCarib | ID: med-17989

RESUMEN

OBJECTIVE: Medical tourism is a practice that involves patients’ intentional travel to privately obtain medical services in another country. Our objective was to consult with diverse lawyers from across Barbados to explore their views on the prospective legal and regulatory implications of the country’s developing medical tourism industry. DESIGN AND METHODS: After recruiting participants through local legal societies and local networks, we held a focus group in February 2014 in Bridgetown with nine lawyers with diverse legal backgrounds. Focus group moderators summarized the study objective and engaged participants in identifying the local implications of medical tourism and the anticipated legal and regulatory concerns. The focus group discussion was transcribed verbatim and analyzed thematically. RESULTS: Five dominant legal and regulatory themes were identified: (1) liability; (2) immigration law; (3) physician licensing; (4) corporate ownership; and (5) reputational protection. Two predominant ethico-legal concerns raised by participants are also heavily reflected in the existing literature: the ability of medical tourists to recover medical malpractice from physicians practicing in Barbados for adverse events; and the effects of medical tourism on local citizens’ access to health care in the destination country. CONCLUSIONS: Overall this analysis reveals that lawyers in Barbados have an important role to play in the medical tourism sector beyond litigation – particularly in transactional and gatekeeper capacities. It remains to be seen whether these findings are specific to Barbados or can be extrapolated to other medical tourism destination countries in the Anglophone Caribbean and beyond.


Asunto(s)
Viaje , Viaje/legislación & jurisprudencia , Atención Médica , Barbados
7.
Zootaxa ; 3754: 381-419, 2014 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-24869697

RESUMEN

Reproductive timing, fecundity, and average egg sizes were examined for galatheoid and chirostyloid squat lobster collections from the Gulf of Mexico. While congeners did not always significantly differ in egg size or timing, each genus had a unique average egg diameter size which may indicate whether the developing embryos will be lecithotrophic or planktotrophic larvae. The eggs of Eumunididae, Galatheidae, and Munididae were more numerous and smaller than the larger and less abundant eggs of Chirostylidae and Munidopsidae. With the exception of members of the Munididae, members of genera within the same family had distinct egg diameters. Ovigerous females were significantly larger than non-ovigerous females in some species (i.e., Uroptychus nitidus, Munida forceps, Galacantha spinosa, Munidopsis abbreviata, M. alaminos, M., erinacea, M. robusta, M. sigsbei, and M. simplex). Munidopsis erinacea and Munida affinis males were significantly larger than females; the reverse was true for Munidopsis robusta and Munidopsis simplex. All other species studied did not have a significant difference between males and females. The spatial and bathymetric ranges for many species are extended in this study from prior reports. Seasonality of reproduction was evident in few species, but this may be a result of limited sample sizes.


Asunto(s)
Decápodos/fisiología , Animales , Femenino , Fertilidad , Geografía , Golfo de México , Larva , Modelos Lineales , Masculino , Óvulo , Reproducción
8.
Minerva Anestesiol ; 78(4): 426-33, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22240618

RESUMEN

BACKGROUND: Acute normovolemic hemodilution (ANH) is an alternative to blood transfusion in surgeries involving blood loss. This experimental study was designed to evaluate whether pulse pressure variation (PPV) would be an adequate tool for monitoring changes in preload during ANH, as assessed by transesophageal echocardiography. METHODS: Twenty-one anesthetized and mechanically ventilated pigs were randomized into three groups: CTL (control), HES (hemodilution with 6% hydroxyethyl starch at a 1:1 ratio) or NS (hemodilution with saline 0.9% at a 3:1 ratio). Hemodilution was performed in animals of groups NS and HES in two stages, with target hematocrits 22% and 15%, achieved at 30-minute intervals. After two hours, 50% of the blood volume withdrawn was transfused and animals were monitored for another hour. Statistical analysis was based on ANOVA for repeated measures followed by multiple comparison test (P<0.05). Pearson's correlations were performed between changes in left ventricular end-diastolic volume (LVEDV) and PPV, central venous pressure (CVP) and pulmonary artery occlusion pressure (PAOP). RESULTS: Group NS received a significantly greater amount of fluids during ANH (NS, 900 ± 168 mL vs. HES, 200 ± 50 mL, P<0.05) and presented greater urine output (NS, 2643 ± 1097 mL vs. HES, 641 ± 338 mL, P<0.001). Significant decreases in LVEDV were observed in group NS from completion of ANH until transfusion. In group HES, only increases in LVEDV were observed, at the end of ANH and at transfusion. Such changes in LVEDV (∆LVEDV) were better reflected by changes in PPV (∆PPV, R=-0.62) than changes in CVP (∆CVP, R=0.32) or in PAOP (∆PAOP, R=0.42, respectively). CONCLUSION: Changes in preload during ANH were detected by changes in PPV. ∆PPV was superior to ∆PAOP and ∆CVP to this end.


Asunto(s)
Presión Sanguínea/fisiología , Volumen Sanguíneo/fisiología , Hemodilución/métodos , Animales , Superficie Corporal , Peso Corporal/fisiología , Presión Venosa Central/fisiología , Coloides/uso terapéutico , Soluciones Cristaloides , Ecocardiografía Transesofágica , Corazón/fisiología , Hemodinámica/fisiología , Soluciones Isotónicas/uso terapéutico , Sustitutos del Plasma/uso terapéutico , Arteria Pulmonar/fisiología , Porcinos
9.
Vet Parasitol ; 160(3-4): 337-9, 2009 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-19128882

RESUMEN

Fifty apparently healthy island dogs presenting to the Ross University School of Veterinary Medicine (RUSVM), St. Kitts, West Indies for neutering were used in this prospective study. Twelve of the dogs (24%) were diagnosed with spirocercosis based on a positive fecal analysis and characteristic lesions seen during esophagoscopy. Routine thoracic survey radiographs revealed changes previously reported with spirocercosis in 10/12 (sensitivity=83%) infected dogs, but in none of the uninfected dogs (38/38; specificity=100%). The most common radiographic changes were an increased fluid density within the caudal dorsal thorax on the lateral view and a widening and/or bulging of the caudal mediastinum on the dorsoventral view. After oral administration of barium sulfate, barium retention or a tortuous esophagus was visible in all infected dogs (12/12; sensitivity 100%) and in one uninfected dog (1/38; specificity 97%). The results show spirocercosis is common on St. Kitts and that radiographs are as dependable as fecal analysis and/or endoscopy in diagnosing the condition.


Asunto(s)
Enfermedades de los Perros/diagnóstico por imagen , Radiografía Torácica/veterinaria , Infecciones por Spirurida/veterinaria , Thelazioidea/aislamiento & purificación , Animales , Diagnóstico Diferencial , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/epidemiología , Perros , Heces/parasitología , Femenino , Masculino , Estudios Prospectivos , Radiografía Torácica/normas , San Kitts y Nevis/epidemiología , Sensibilidad y Especificidad , Infecciones por Spirurida/diagnóstico , Infecciones por Spirurida/diagnóstico por imagen , Infecciones por Spirurida/epidemiología
10.
Science ; 321(5893): 1214-7, 2008 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-18755979

RESUMEN

The archaeology of pre-Columbian polities in the Amazon River basin forces a reconsideration of early urbanism and long-term change in tropical forest landscapes. We describe settlement and land-use patterns of complex societies on the eve of European contact (after 1492) in the Upper Xingu region of the Brazilian Amazon. These societies were organized in articulated clusters, representing small independent polities, within a regional peer polity. These patterns constitute a "galactic" form of prehistoric urbanism, sharing features with small-scale urban polities in other areas. Understanding long-term change in coupled human-environment systems relating to these societies has implications for conservation and sustainable development, notably to control ecological degradation and maintain regional biodiversity.


Asunto(s)
Arqueología , Ciudades/historia , Cultura , Árboles , Agricultura/historia , Biodiversidad , Brasil , Ecosistema , Planificación Ambiental , Historia Antigua , Humanos , Características de la Residencia , Ríos
11.
Burns ; 33(5): 613-20, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17418954

RESUMEN

UNLABELLED: Experimental models showed the ability of Pseudomonas aeruginosa to interact with epidermal keratinocytes [Green H, Kehinde O, Thomas J. Growth of cultured human epidermal cells into multiple epithelia suitable for grafting. Proc Natl Acad Sci USA 1979;76(11):5665-8], stimulating these cells to produce specific peptides that start an immunological chain reaction in the epidermis [O'Connor NE, Mulliken JB, Banks-Schlegel S, Kehinde O, Green H. Grafting of burns with cultured epithelium prepared from autologous epidermal cells. Lancet 1981;(1):75-8]. The immune reaction causes the release of cytokines and growth factors. The objective of this study was to test whether the presence of keratinocyte growth factor (KGF) alters P. aeruginosa proliferation in an experimental burn model. METHODS: Human keratinocytes derived from neonatal foreskins were isolated and cultured following standard methods [Gallico III, GG, O'Connor NE, Compton CC, Kehinde O, Green H. Permanent coverage of large burn wounds with autologous cultured human epithelium. N Engl J Med 1984;311(7):448-51]. Some of these cells were genetically modified to produce KGF, and the other cells were supplemented with different KGF concentrations in the culture media. Both groups of keratinocytes were seeded in collagen matrices and cultured to form stratified epithelia. A hot plate was used to produce burn defects. Each matrix was inoculated with luminescent P. aeruginosa strain. Experiments were made using keratinocytes without KGF, keratinocytes supplemented with different concentrations of KGF, and keratinocytes genetically modified to produce KGF. Statistical analyses were made using Wilcoxon paired test. RESULTS: When KGF was added to P. aeruginosa in the presence of keratinocytes, bacterial growth was inhibited, and the same was observed when genetically modified keratinocytes were used. CONCLUSION: Many studies have been done on KGF, where its known properties were defined as a mitogen for keratinocytes [Munster AM. Cultured skin for massive burns: a prospective, controlled trial. Ann Surg 1996;224(3):372-7]. This method allows for a qualitative and quantitative evaluation in real time of the bacterial growth in wound sites after bacterial inoculation. KGF was involved in the reduction of bacterial viability. However, as KGF alone did not produce any effect on P. aeruginosa, it seems to modulate the skin innate immune response.


Asunto(s)
Quemaduras/patología , Proliferación Celular/efectos de los fármacos , Factor 7 de Crecimiento de Fibroblastos/farmacología , Pseudomonas aeruginosa/crecimiento & desarrollo , Animales , Quemaduras/microbiología , Relación Dosis-Respuesta a Droga , Humanos , Queratinocitos/citología , Ratones , Modelos Biológicos , Células 3T3 NIH
12.
Philos Trans R Soc Lond B Biol Sci ; 362(1478): 197-208, 2007 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-17255029

RESUMEN

For centuries Amazonia has held the Western scientific and popular imagination as a primordial forest, only minimally impacted by small, simple and dispersed groups that inhabit the region. Studies in historical ecology refute this view. Rather than pristine tropical forest, some areas are better viewed as constructed or 'domesticated' landscapes, dramatically altered by indigenous groups in the past. This paper reviews recent archaeological research in several areas along the Amazon River with evidence of large pre-European (ca 400-500 calendar years before the present) occupations and large-scale transformations of forest and wetland environments. Research from the southern margins of closed tropical forest, in the headwaters of the Xingu River, are highlighted as an example of constructed nature in the Amazon. In all cases, human influences dramatically altered the distribution, frequency and configurations of biological communities and ecological settings. Findings of historical change and cultural variability, including diverse small to medium-sized complex societies, have clear implications for questions of conservation and sustainability and, specifically, what constitutes 'hotspots' of bio-historical diversity in the Amazon region.


Asunto(s)
Arqueología/historia , Biodiversidad , Características Culturales , Evolución Cultural , Ríos , Brasil , Historia Medieval , Humanos
14.
J Burn Care Rehabil ; 23(2): 126-31, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-11882802

RESUMEN

The differentiation and barrier formation of cultured composite skin grafts (CSGs) were assessed by histology and measurements of surface electrical capacitance (SEC) in vitro and in vivo. Keratinocytes cultured on the surface of acellular dermis were lifted to the air-liquid interface and analyzed for 30 days in vitro. Initially, SEC measurements of CSGs (n = 11) were high but quickly dropped between days 4 and 6 and remained steady for 30 days, indicating barrier formation by the epidermis. Histology of the CSGs (n = 6) demonstrated stratification of the epidermal cells and partial formation of the stratum corneum by day 3 that was complete by day 7. CSGs (n = 5) were transplanted to athymic mice, where they formed a stratified and differentiated epidermis. SEC measurements of CSGs remained low after transplant, suggesting that exposure to the air-liquid interface improved the maturation of CSGs in vitro prior to transplant.


Asunto(s)
Queratinocitos/fisiología , Trasplante de Piel , Animales , Diferenciación Celular , Técnicas Citológicas , Capacidad Eléctrica , Humanos , Ratones , Ratones Desnudos , Factores de Tiempo
17.
Parasitol Res ; 87(10): 840-8, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11688891

RESUMEN

Echinostoma paraensei Lie and Basch, 1967 (Echinostomatidae:Platyhelminthes), a 37 collar spine echinostome of the "revolutum group", has been used extensively as a model organism to study the interactions of digenetic trematodes with both their snail and vertebrate hosts. This worm was first isolated from the snail Biomphalaria glabrata from Belo Horizonte (BH isolate), Minas Gerais State, Brazil, by Lie and Basch [J Parasitol (1967) 53:1192-1199]. The natural definitive host for the BH isolate was never determined, and it has been maintained in the laboratory since 1967 in B. glabrata and hamsters. In this study, using light and scanning electron microscopy and molecular analysis, we describe an echinostome recently obtained from its natural vertebrate host, the wild rodent Nectomys squamipes (Rodentia: Sigmodontinae) from Sumidouro, Rio de Janeiro State, Brazil (RJ isolate). This echinostome was also compared to the laboratory-maintained BH isolate of E. paraensei. We observed that adult worms of both BH and RJ isolates could be differentiated from other echinostome species by the relatively small size of the dorsal collar spines relative to lateral and corner collar spines. SEM confirmed the similarity of this morphological character between the two isolates. As additional diagnostic features, the tegumentary spines are scale-like and the region between the genital pore and the acetabulum lacks scales. There is a folded protuberance with a pore just posterior to the genital pore. The tegument of the acetabulum is unspined and radially wrinkled, and there are numerous randomly distributed small, domed, ciliated papillae. The sequences of the internal transcribed spacers of the nuclear rDNA complex of the RJ and BH isolates are identical. Together these shared features provide strong evidence that both isolates are the same and can be referred to as E. paraensei. In conclusion, we have identified, for the first time, one of the natural definitive hosts for E. paraensei, the rodent N. squamipes, and have extended the known geographical distribution of this species to include Sumidouro in Rio de Janeiro State, Brazil.


Asunto(s)
Echinostoma/clasificación , Equinostomiasis/parasitología , Roedores/parasitología , Animales , ADN de Helmintos/análisis , ADN Ribosómico/análisis , Echinostoma/anatomía & histología , Echinostoma/genética , Echinostoma/aislamiento & purificación , Echinostoma/ultraestructura , Microscopía Electrónica de Rastreo , Datos de Secuencia Molecular , Análisis de Secuencia de ADN
18.
Parasitology ; 123 Suppl: S211-28, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11769285

RESUMEN

Schistosoma mansoni is one of the most abundant infectious agents of humankind. Its widespread distribution is permitted by the broad geographic range of susceptible species of the freshwater snail genus Biomphalaria that serve as obligatory hosts for its larval stages. Molecular phylogenetic studies suggest that Schistosoma originated in Asia, and that a pulmonate-transmitted progenitor colonized Africa and gave rise to both terminal-spined and lateral-spined egg species groups, the latter containing S. mansoni. Schistosoma mansoni likely appeared only after the trans-Atlantic dispersal of Biomphalaria from the Neotropics to Africa, an event that, based on the present African fossil record, occurred only 2-5 million years ago. This parasite became abundant in tropical Africa and then entered the New World with the slave trade. It prospered in the Neotropics because a remarkably susceptible and productive host, B. glabrata, was widely distributed there. Indeed, a snail similar to B. glabrata may have given rise to the African species of Biomphalaria. Schistosoma mansoni has since spread into other Neotropical Biomphalaria species and mammalian hosts. The distribution of S. mansoni is in a state of flux. In Egypt, S. mansoni has nearly completely replaced S. haematobium in the Nile Delta, and has spread to other regions of the country. A susceptible host snail, B. straminea, has been introduced into Asia and there is evidence of S. mansoni transmission in Nepal. Dam and barrage construction has lead to an epidemic of S. mansoni in Senegal, and the parasite continues its spread in Brazil. Because of competition with introduced aquatic species and environmental changes, B. glabrata and consequently S. mansoni have become less abundant on the Caribbean islands. Control of S. mansoni using praziquantel and oxamniquine has reduced global prevalence but control is difficult to sustain, and S. mansoni can develop tolerance/resistance to praziquantel, raising concerns about its future efficacy. Because of legitimate environmental concerns, snail control is unlikely to be an option in future control efforts. Global warming will impact the distribution of Biomphalaria and S. mansoni, but the magnitude and nature of the effects are poorly understood.


Asunto(s)
Biomphalaria/parasitología , Schistosoma mansoni/crecimiento & desarrollo , Esquistosomiasis/epidemiología , África/epidemiología , Animales , Asia/epidemiología , Biomphalaria/crecimiento & desarrollo , ADN de Helmintos/química , ADN de Helmintos/genética , Fósiles , Humanos , Filogenia , Esquistosomiasis/prevención & control , América del Sur/epidemiología , Agua/parasitología , Indias Occidentales/epidemiología
19.
Ing. sanit. ambient ; (25): 63-70, 1996.
Artículo en Español | BINACIS | ID: biblio-1162585

RESUMEN

Se evalua el tiempo de contacto agua-desinfectante, uno de los factores clave para determinar el cumplimiento de la Regla de Tratamiento de Agua Superficial de la USEPA, para determinados objetivos


Asunto(s)
Desinfección del Agua , Purificación del Agua
20.
Artículo en Español | BINACIS | ID: bin-138401

RESUMEN

Se evalua el tiempo de contacto agua-desinfectante, uno de los factores clave para determinar el cumplimiento de la Regla de Tratamiento de Agua Superficial de la USEPA, para determinados objetivos


Asunto(s)
Purificación del Agua , Desinfección del Agua
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA