30 research outputs found
Severe Dengue Virus Infection in Travelers: Risk Factors and Laboratory Indicators
Background. Dengue fever is the most common arboviral disease in travelers. In countries where dengue virus is endemic, sequential (secondary) infections with different dengue virus serotypes are associated with disease severity. Data on severity and secondary infection rates in a population of travelers are lacking. Methods. Intensified surveillance of dengue fever in travelers was performed within the European Network on Surveillance of Imported Infectious Diseases. Data were collected at 14 European clinical referral centers between 2003 and 2005. Results. A total of 219 dengue virus infections imported from various regions of endemicity were reported. Serological analysis revealed a secondary immune response in 17%. Spontaneous bleeding was observed in 17 (8%) patients and was associated with increased serum alanine and aspartate aminotransferase levels and lower median platelet counts. Two (0.9%) patients fulfilled the World Health Organization (WHO) case definition for dengue hemorrhagic fever. However, 23 (11%) travelers had severe clinical manifestations (internal hemorrhage, plasma leakage, shock, or marked thrombocytopenia). A secondary immune response was significantly associated with both spontaneous bleeding and other severe clinical manifestations. Conclusions. In travelers, severe dengue virus infections are not uncommon but may be missed if the WHO classification is strictly applied. High liver enzyme levels and low platelet counts could serve as indicators of disease severit
Schistosomiasis in european travelers and migrants: Analysis of 14 years tropnet surveillance data
Filariosis por onchocerca volvulus , loa loa y mansonella pers tans. Analisis epidemiológico, clínico, anal ítico y parasitológico
[ES] Esta tesis tiene como objetivo conocer las caracteristicas epidemiologicas, clinicas, analiticas y parasitologicas de las
tres especies de filariosis diagnosticadas mas frecuentemente en nuestro medio.
Los objetivos más especiífcos:
1. Identificar la frecuencia de casos asintomaticos en pacientes con filariosis.
2. Definir la frecuencia de aparicion de los diferentes sintomas en las tres especies de
filariosis analizadas: Onchocerca volvulus, Loa loa y Mansonella perstans.
3. Estudiar las diferencias clinicas y analiticas entre nativos de zona endemica y viajeros
a zonas endemicas.
4. Determinar los criterios diagnosticos mas frecuentes en cada una de las especies y sus
diferencias entre las poblaciones estudiadas.
5. Delimitar el tiempo de residencia necesario en zona endemica de filariosis para adquirir
la enfermedad, asi como delimitar cuanto tiempo despues de haber salido de zona
endemica se pueden diagnosticar las filariosis.[EN] This thesis aims to know the epidemiological, clinical, and parasitological the analytical three species of filariasis diagnosed more frequently in our environment.
Specifc objectives:
1. Identify the frequency of asymptomatic cases in patients with filariasis.
2. Define the frequency of occurrence of different symptoms in the three species of filariasis analyzed: Onchocerca volvulus, Loa loa and perstans Mansonella.
3. To study the clinical and analytical differences between natives and travelers endemic area to endemic areas.
4. Determine the most frequent diagnostic criteria in each of the species and their differences between the populations studied.
5. Define the required period of residence in endemic filariasis area to acquire disease, also define how long after you have left area endemic filariasis can be diagnosed
Imported submicroscopic malaria in Madrid
BACKGROUND: Submicroscopic malaria (SMM) can be defined as low-density infections of Plasmodium that are unlikely to be detected by conventional microscopy. Such submicroscopic infections only occasionally cause acute disease, but they are capable of infecting mosquitoes and contributing to transmission. This entity is frequent in endemic countries; however, little is known about imported SMM.The goals of this study were two-fold: a) to know the frequency of imported SMM, and b) to describe epidemiological, laboratorial and clinical features of imported SMM. METHODS: A retrospective study based on review of medical records was performed. The study population consisted of patients older than 15 years attended at the Tropical Medicine Unit of Hospital Carlos III, between January 1, 2002 and December 31, 2007. Routinely detection techniques for Plasmodium included Field staining and microscopic examination through thick and thin blood smear. A semi-nested multiplex malaria PCR was used to diagnose or to confirm cases with low parasitaemia. RESULTS: SMM was diagnosed in 104 cases, representing 35.5% of all malaria cases. Mean age (IC95%) was 40.38 years (37.41-43.34), and sex distribution was similar. Most cases were in immigrants, but some cases were found in travellers. Equatorial Guinea was the main country where infection was acquired (81.7%). Symptoms were present only in 28.8% of all SMM cases, mainly asthenia (73.3% of symptomatic patients), fever (60%) and arthromialgias (53.3%). The associated laboratory abnormalities were anaemia (27.9%), leukopaenia (15.4%) and thrombopaenia (15.4%). Co-morbidity was described in 75 cases (72.1%). CONCLUSIONS: Results from this study suggest that imported SMM should be considered in some patients attended at Tropical Medicine Units. Although it is usually asymptomatic, it may be responsible of fever, or laboratory abnormalities in patients coming from endemic areas. The possibility of transmission in SMM has been previously described in endemic zones, and presence of vector in Europe has also been reported. Implementation of molecular tests in all asymptomatic individuals coming from endemic area is not economically feasible. So re-emergence of malaria (Plasmodium vivax) in Europe may be speculated.This study was supported by RICET RD06/0021/0003 ISCIII-RETICS.S
Prácticas de fertilización y población optima para siembras de maíz en las regiones tropicales de Veracruz
Growth of carbon nanofilaments on coal foams
8 pages, 7 figures, 2 tables.-- Available online 19 August 2008.Nanofilamentous carbon was grown on a carbon foam by catalytic chemical vapour deposition (CVD) using the decomposition of ethylene/hydrogen mixtures over Ni. The carbon foam was obtained from a coal by a two-stage thermal process, with the first stage taking place at a temperature within the plastic region of the precursor coal. The extent of porosity and the pore size of the foam were mainly influenced by the pressure reached in the reactor during the first stage. In the CVD process, 700°C was the optimum temperature for obtaining good yields of nanofilaments. A low ethylene/hydrogen ratio (1/4) in the reactive gas gave rise to almost only short and thin carbon nanostructures. A higher proportion of C2H4 (4/1, C2H4/H2) gave better yields of nanofilaments, with good proportions of higher-length and higher-diameter (up to around 0.5 μm) structures. Among the carbon forms produced, transmission electron microscopy revealed the predominance of fishbone-type nanofibres, with some bamboo-like nanotubes being also observed.The authors thank the Fundación para el Fomento en Asturias de la Investigación Científica Aplicada y la Tecnología (FICYT, Asturias, Spain) (Project ref., PB02-132), and the Spanish Ministry of Education and Science (MEC) (project ref., NAT2005-04658) for financial support. MC acknowledges CSIC-ESF for the award of an I3P contract.Peer reviewe
Imported submicroscopic malaria in Madrid
Abstract Background Submicroscopic malaria (SMM) can be defined as low-density infections of Plasmodium that are unlikely to be detected by conventional microscopy. Such submicroscopic infections only occasionally cause acute disease, but they are capable of infecting mosquitoes and contributing to transmission. This entity is frequent in endemic countries; however, little is known about imported SMM. The goals of this study were two-fold: a) to know the frequency of imported SMM, and b) to describe epidemiological, laboratorial and clinical features of imported SMM. Methods A retrospective study based on review of medical records was performed. The study population consisted of patients older than 15 years attended at the Tropical Medicine Unit of Hospital Carlos III, between January 1, 2002 and December 31, 2007. Routinely detection techniques for Plasmodium included Field staining and microscopic examination through thick and thin blood smear. A semi-nested multiplex malaria PCR was used to diagnose or to confirm cases with low parasitaemia. Results SMM was diagnosed in 104 cases, representing 35.5% of all malaria cases. Mean age (IC95%) was 40.38 years (37.41-43.34), and sex distribution was similar. Most cases were in immigrants, but some cases were found in travellers. Equatorial Guinea was the main country where infection was acquired (81.7%). Symptoms were present only in 28.8% of all SMM cases, mainly asthenia (73.3% of symptomatic patients), fever (60%) and arthromialgias (53.3%). The associated laboratory abnormalities were anaemia (27.9%), leukopaenia (15.4%) and thrombopaenia (15.4%). Co-morbidity was described in 75 cases (72.1%). Conclusions Results from this study suggest that imported SMM should be considered in some patients attended at Tropical Medicine Units. Although it is usually asymptomatic, it may be responsible of fever, or laboratory abnormalities in patients coming from endemic areas. The possibility of transmission in SMM has been previously described in endemic zones, and presence of vector in Europe has also been reported. Implementation of molecular tests in all asymptomatic individuals coming from endemic area is not economically feasible. So re-emergence of malaria (Plasmodium vivax) in Europe may be speculated.</p