Search results for " Tropical"
showing 10 items of 389 documents
Taste, a new incentive to switch to (R)-praziquantel in schistosomiasis treatment.
2009
Background Praziquantel (PZQ) is the drug compound of choice in the control and treatment of schistosomiasis. PZQ is administered as a racemate, i. e. 1∶1 mixture of enantiomers. The schistosomicidal activity arises from one PZQ-enantiomer, whereas the other enantiomer does not contribute to the activity. The WHO's Special Programme for Research and Training in Tropical Diseases (TDR) has assigned the low-cost preparation of pure schistosomicidal (−)-PZQ a key priority for future R&D on PZQ, but so far this transition has not happened. PZQ has two major administration drawbacks, the first being the high dose needed, and its well documented bitter and disgusting taste. Attempts of taste-mask…
A Simple Fusion Method for Image Time Series Based on the Estimation of Image Temporal Validity
2015
High-spatial-resolution satellites usually have the constraint of a low temporal frequency, which leads to long periods without information in cloudy areas. Furthermore, low-spatial-resolution satellites have higher revisit cycles. Combining information from high- and low- spatial-resolution satellites is thought a key factor for studies that require dense time series of high-resolution images, e.g., crop monitoring. There are several fusion methods in the bibliography, but they are time-consuming and complicated to implement. Moreover, the local evaluation of the fused images is rarely analyzed. In this paper, we present a simple and fast fusion method based on a weighted average of two in…
A mid-term estimate of 2018/2019 vaccine effectiveness to prevent laboratory confirmed A(H1N1)pdm09 and A(H3N2) influenza cases in Sicily (Italy)
2019
Abstract Influenza season started in Italy during the month of October 2018, approaching the epidemic peak in January 2019. This report aim to explore the mid-term virologic surveillance data of the 2018–2019 influenza season in Sicily and to estimate the effectiveness of seasonal influenza vaccine (VE) against A(H1N1)pdm09 and A(H3N2) influenza viruses. A test-negative design was used to evaluate influenza VE. In Sicily, almost all influenza infections were sustained by influenza type A viruses, of which 62.3% were A(H3N2) and 36.3% A(H1N1)pdm09. A reduction of laboratory confirmed influenza cases in Sicilian population immunized against influenza were observed. In particular, an overall s…
S. haematobium as a Common Cause of Genital Morbidity in Girls: A Cross-sectional Study of Children in South Africa
2013
Background Schistosoma (S.) haematobium infection is a common cause of genital morbidity in adult women. Ova in the genital mucosal lining may cause lesions, bleeding, pain, discharge, and the damaged surfaces may pose a risk for HIV. In a heterogeneous schistosomiasis endemic area in South Africa, we sought to investigate if young girls had genital symptoms and if this was associated with urinary S. haematobium. Methodology In a cross-sectional study of 18 randomly chosen primary schools, we included 1057 schoolgirls between the age of 10 and 12 years. We interviewed assenting girls, whose parents had consented to their participation and examined three urines from each of them for schistos…
Identifying and validating the presence of guanine-quadruplexes (G4) within the blood fluke parasite schistosoma mansoni
2021
Schistosomiasis is a neglected tropical disease that currently affects over 250 million individuals worldwide. In the absence of an immunoprophylactic vaccine and the recognition that mono-chemotherapeutic control of schistosomiasis by praziquantel has limitations, new strategies for managing disease burden are urgently needed. A better understanding of schistosome biology could identify previously undocumented areas suitable for the development of novel interventions. Here, for the first time, we detail the presence of G-quadruplexes (G4) and putative quadruplex forming sequences (PQS) within the Schistosoma mansoni genome. We find that G4 are present in both intragenic and intergenic regi…
From the Field to the Laboratory: Quantifying Outdoor Mosquito Landing Rate to Better Evaluate Topical Repellents.
2021
Abstract Vector-borne diseases are a worldwide threat to human health. Often, no vaccines or treatments exist. Thus, personal protection products play an essential role in limiting transmission. The World Health Organization (WHO) arm-in-cage (AIC) test is the most common method for evaluating the efficacy of topical repellents, but it remains unclear whether AIC testing conditions recreate the mosquito landing rates in the field. This study aimed to estimate the landing rate outdoors, in an area of Europe highly infested with the Asian tiger mosquito (Aedes albopictus (Skuse, 1894, Diptera: Culididae)), and to determine how to replicate this rate in the laboratory. To assess the landing ra…
Ecological, morphological and genetic characterization of sympatric Haemonchus spp. parasites of domestic ruminants in Mauritania
1995
SUMMARYThe 4 species of ruminants (dromedary, zebu cattle, sheep and goat) in arid areas of Mauritania harboured Haemonchus spp. as the most frequent internal parasite. This was a rare situation where the 3 putative species, H. longistipes (dromedary), H. placet (zebu cattle) and H. contortus (sheep and goat) occurred sympatrically. The study was undertaken on hosts slaughtered at the Nouakchott abattoir, on the basis of monthly collection of worms. The environment was very unfavourable to H. placei and unfavourable to H. contortus, as intensity of infection remained low throughout the year, whereas infection in the dromedary was 10 to 20-fold higher. The survival strategies during the long…
Evidence for Transmission of Taenia solium Taeniasis/Cysticercosis in a Rural Area of Northern Rwanda
2021
Cysticercosis is a parasitic infection caused by the metacestode larval stage (cysticercus) of Taenia solium. In humans, cysticercosis may infect the central nervous system and cause neurocysticercosis, which is responsible for over 50,000 deaths per year worldwide and is the major cause of preventable epilepsy cases, especially in low-income countries. Cysticercosis infection is endemic in many less developed countries where poor hygiene conditions and free-range pig management favor their transmission. A cross-sectional study was conducted in 680 children from a rural primary school in Gakenke district (Northern province of Rwanda). Stool samples were collected from participants and analy…
Who can go back to work when the COVID-19 pandemic remits?
2020
AbstractThis paper seeks to determine which workers affected by lockdown measures can return to work when a government decides to apply lockdown exit strategies. This system, which we call Sequential Selective Multidimensional Decision (SSMD), involves deciding sequentially, by geographical areas, sectors of activity, age groups and immunity, which workers can return to work at a given time according to the epidemiological criteria of the country as well as that of a group of reference countries, used as a benchmark, that have suffered a lower level of lockdown de-escalation strategies. We apply SSMD to Spain, based on affiliation to the Social Security system prior to the COVID-19 pandemic…
Analysis of climatic data and forecast indices for human fascioliasis at very high altitude
1999
Human infection with Fasciola hepatica has recently been recognized as an important health problem worldwide, and particularly at very high altitudes in South America. The highest prevalences and intensities of human fascioliasis known are those of the northern Bolivian Altiplano, where infected Lymnaea truncatula occur at altitudes of 3800-4100 m. In the present study, the climatic data for this area of the Altiplano, which differ markedly from those of endemic areas in the lowlands, were analysed. There is no marked seasonality in temperature but there are large variations in temperature within a daily, 24-h period. Rainfall is seasonal, with a long dry season, coinciding with the lowest …