46 research outputs found

    Status of onchocerciasis in Teppi area, Southwestern Ethiopia, after four years of annual community-directed treatment with ivermectin

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    Background: Information on the impact of annual community-directed treatment with ivermectin (CDTI) on the prevalence and intensity of onchocerciasis as well as its transmission following years of repeated ivermectin distribution is vital to monitor the impact of the control efforts.Objective: To determine the status of the prevalence and intensity of onchocerciasis after four years of ivermectin distribution in Teppi area.Methods: Skin snips were obtained from 390 study participants and kept in physiological saline at room temperature for 24 hours. The emerged microfilariae were counted under 10x microscope objective. The skin snips were weighed and the microfilarial load was expressed as the arithmetic mean of two skin snips per mg of skin snip.Results: Out of the total 390 examined subjects, 87 (22.3%) were found to be positive for microfilaridermia. Significant differences in the prevalence and microfilarial load of the disease were not found among untreated and treated subjects (p > 0.05). Significant reductions of the prevalence (25.5%) and intensity of infection (0.08 – 8mf, mean 1.3) were found compared to prevalence (81%) and intensity of infection ( 0-855, mean 33 ± 5.6) reported before the initiation of the CDTI programme in the study area.Conclusion: The overall results of the study showed a high reduction both in the prevalence and intensity of infection compared to prevalence and intensity of the disease before the initiation of the CDTI programme in the study area. Nevertheless, continued assessment of the long-term impact of repeated annual CDTI programme on onchocerciasis and identification of factors that could affect the sustainability of the programme in various CDTI areas of Ethiopia, could contribute towards the effective control of the programme. [Ethiop. J. Health Dev. 2010;24(1):51-56

    Cellular and Cytokine Responses in the Granulomas of Asymptomatic Cattle naturally infected with Mycobacterium bovis in Ethiopia

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    Cells (CD3+ T cell and CD68+ macrophages), cytokines (IFN-γ+ and TNF-α+) and effector molecule (iNOS+) responses were evaluated in the lymph nodes and tissue of cattle naturally infected with Detailed post mortem and immunohistochemical examinations of lesions were performed on 16 cows positive for single intradermal cervical comparative tuberculin (SICCT) test which were identified from dairy farms located around the Addis Ababa City. The severity of the gross lesion was significantly higher (p=0.003) in culture positive (n=12) cows than in culture negative (n=4). Immunohistochemical techniques showed that in culture positive cows, the mean immunolabeling fraction of CD3+ T cells decreased as the stage of granuloma increased from stage I to stage IV (p<0.001). In contrast, the immunolabelling fraction of CD68+ macrophages, IFN-γ+, TNF-α+ and iNOS+ increased from stage I to stage IV (p< 0.001). In culture negative cows, early stages showed a significantly higher fraction of CD68+ macrophages (p=0.03) and iNOS+ (p=0.007) when compared to culture positive cows. Similarly, at advanced granuloma stages, culture negative cows demonstrated significantly higher mean proportions of CD3+ T cells (p< 0.001) compared to culture positive cows. Thus, this study demonstrates that following natural infection of cows with , as the stage of granuloma increases from stage I to stage IV, the immunolabelling fraction of CD3+ cells decreases while the immunolabeling fraction of CD68+ macrophages, IFN-γ+, TNF-α+ and iNOS+ increases. [Abstract copyright: Copyright © 2020 Tulu et al.

    Impact of co-adsorbed oxygen on crotonaldehyde adsorption over gold nanoclusters : a computational study

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    Crotonaldehyde (2-butenal) adsorption over gold sub-nanometer particles, and the influence of co-adsorbed oxygen, has been systematically investigated by computational methods. Using density functional theory, the adsorption energetics of crotonaldehyde on bare and oxidised gold clusters (Au13, d = 0.8 nm) were determined as a function of oxygen coverage and coordination geometry. At low oxygen coverage, sites are available for which crotonaldehyde adsorption is enhanced relative to bare Au clusters by 10 kJ mol−1. At higher oxygen coverage, crotonaldehyde is forced to adsorb in close proximity to oxygen weakening adsorption by up to 60 kJ mol−1 relative to bare Au. Bonding geometries, density of states plots and Bader analysis, are used to elucidate crotonaldehyde bonding to gold nanoparticles in terms of partial electron transfer from Au to crotonaldehyde, and note that donation to gold from crotonaldehyde also becomes significant following metal oxidation. At high oxygen coverage we find that all molecular adsorption sites have a neighbouring, destabilising, oxygen adatom so that despite enhanced donation, crotonaldehyde adsorption is always weakened by steric interactions. For a larger cluster (Au38, d = 1.1 nm) crotonaldehyde adsorption is destabilized in this way even at a low oxygen coverage. These findings provide a quantitative framework to underpin the experimentally observed influence of oxygen on the selective oxidation of crotyl alcohol to crotonaldehyde over gold and gold–palladium alloys

    Impact of co-adsorbed oxygen on crotonaldehyde adsorption over gold nanoclusters : a computational study

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    Crotonaldehyde (2-butenal) adsorption over gold sub-nanometer particles, and the influence of co-adsorbed oxygen, has been systematically investigated by computational methods. Using density functional theory, the adsorption energetics of crotonaldehyde on bare and oxidised gold clusters (Au13, d = 0.8 nm) were determined as a function of oxygen coverage and coordination geometry. At low oxygen coverage, sites are available for which crotonaldehyde adsorption is enhanced relative to bare Au clusters by 10 kJ mol−1. At higher oxygen coverage, crotonaldehyde is forced to adsorb in close proximity to oxygen weakening adsorption by up to 60 kJ mol−1 relative to bare Au. Bonding geometries, density of states plots and Bader analysis, are used to elucidate crotonaldehyde bonding to gold nanoparticles in terms of partial electron transfer from Au to crotonaldehyde, and note that donation to gold from crotonaldehyde also becomes significant following metal oxidation. At high oxygen coverage we find that all molecular adsorption sites have a neighbouring, destabilising, oxygen adatom so that despite enhanced donation, crotonaldehyde adsorption is always weakened by steric interactions. For a larger cluster (Au38, d = 1.1 nm) crotonaldehyde adsorption is destabilized in this way even at a low oxygen coverage. These findings provide a quantitative framework to underpin the experimentally observed influence of oxygen on the selective oxidation of crotyl alcohol to crotonaldehyde over gold and gold–palladium alloys

    Tuberculosis screening among ambulatory people living with HIV: a systematic review and individual participant data meta-analysis

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    BACKGROUND: The WHO-recommended tuberculosis screening and diagnostic algorithm in ambulatory people living with HIV is a four-symptom screen (known as the WHO-recommended four symptom screen [W4SS]) followed by a WHO-recommended molecular rapid diagnostic test (eg Xpert MTB/RIF [hereafter referred to as Xpert]) if W4SS is positive. To inform updated WHO guidelines, we aimed to assess the diagnostic accuracy of alternative screening tests and strategies for tuberculosis in this population. METHODS: In this systematic review and individual participant data meta-analysis, we updated a search of PubMed (MEDLINE), Embase, the Cochrane Library, and conference abstracts for publications from Jan 1, 2011, to March 12, 2018, done in a previous systematic review to include the period up to Aug 2, 2019. We screened the reference lists of identified pieces and contacted experts in the field. We included prospective cross-sectional, observational studies and randomised trials among adult and adolescent (age ≥10 years) ambulatory people living with HIV, irrespective of signs and symptoms of tuberculosis. We extracted study-level data using a standardised data extraction form, and we requested individual participant data from study authors. We aimed to compare the W4SS with alternative screening tests and strategies and the WHO-recommended algorithm (ie, W4SS followed by Xpert) with Xpert for all in terms of diagnostic accuracy (sensitivity and specificity), overall and in key subgroups (eg, by antiretroviral therapy [ART] status). The reference standard was culture. This study is registered with PROSPERO, CRD42020155895. FINDINGS: We identified 25 studies, and obtained data from 22 studies (including 15 666 participants; 4347 [27·7%] of 15 663 participants with data were on ART). W4SS sensitivity was 82% (95% CI 72-89) and specificity was 42% (29-57). C-reactive protein (≥10 mg/L) had similar sensitivity to (77% [61-88]), but higher specificity (74% [61-83]; n=3571) than, W4SS. Cough (lasting ≥2 weeks), haemoglobin (<10 g/dL), body-mass index (<18·5 kg/m2), and lymphadenopathy had high specificities (80-90%) but low sensitivities (29-43%). The WHO-recommended algorithm had a sensitivity of 58% (50-66) and a specificity of 99% (98-100); Xpert for all had a sensitivity of 68% (57-76) and a specificity of 99% (98-99). In the one study that assessed both, the sensitivity of sputum Xpert Ultra was higher than sputum Xpert (73% [62-81] vs 57% [47-67]) and specificities were similar (98% [96-98] vs 99% [98-100]). Among outpatients on ART (4309 [99·1%] of 4347 people on ART), W4SS sensitivity was 53% (35-71) and specificity was 71% (51-85). In this population, a parallel strategy (two tests done at the same time) of W4SS with any chest x-ray abnormality had higher sensitivity (89% [70-97]) and lower specificity (33% [17-54]; n=2670) than W4SS alone; at a tuberculosis prevalence of 5%, this strategy would require 379 more rapid diagnostic tests per 1000 people living with HIV than W4SS but detect 18 more tuberculosis cases. Among outpatients not on ART (11 160 [71·8%] of 15 541 outpatients), W4SS sensitivity was 85% (76-91) and specificity was 37% (25-51). C-reactive protein (≥10 mg/L) alone had a similar sensitivity to (83% [79-86]), but higher specificity (67% [60-73]; n=3187) than, W4SS and a sequential strategy (both test positive) of W4SS then C-reactive protein (≥5 mg/L) had a similar sensitivity to (84% [75-90]), but higher specificity than (64% [57-71]; n=3187), W4SS alone; at 10% tuberculosis prevalence, these strategies would require 272 and 244 fewer rapid diagnostic tests per 1000 people living with HIV than W4SS but miss two and one more tuberculosis cases, respectively. INTERPRETATION: C-reactive protein reduces the need for further rapid diagnostic tests without compromising sensitivity and has been included in the updated WHO tuberculosis screening guidelines. However, C-reactive protein data were scarce for outpatients on ART, necessitating future research regarding the utility of C-reactive protein in this group. Chest x-ray can be useful in outpatients on ART when combined with W4SS. The WHO-recommended algorithm has suboptimal sensitivity; Xpert for all offers slight sensitivity gains and would have major resource implications. FUNDING: World Health Organization

    A reference map of the human binary protein interactome.

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    Global insights into cellular organization and genome function require comprehensive understanding of the interactome networks that mediate genotype-phenotype relationships(1,2). Here we present a human 'all-by-all' reference interactome map of human binary protein interactions, or 'HuRI'. With approximately 53,000 protein-protein interactions, HuRI has approximately four times as many such interactions as there are high-quality curated interactions from small-scale studies. The integration of HuRI with genome(3), transcriptome(4) and proteome(5) data enables cellular function to be studied within most physiological or pathological cellular contexts. We demonstrate the utility of HuRI in identifying the specific subcellular roles of protein-protein interactions. Inferred tissue-specific networks reveal general principles for the formation of cellular context-specific functions and elucidate potential molecular mechanisms that might underlie tissue-specific phenotypes of Mendelian diseases. HuRI is a systematic proteome-wide reference that links genomic variation to phenotypic outcomes

    IMPACT OF CATTLE KEEPING ON HUMAN BITING RATE OF ANOPHELINE MOSQUITOES AND MALARIA TRANSMISSION AROUND ZIWAY, ETHIOPIA

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    Objective: To assess the impact of livestock keeping on the human biting rate (HBR)of anopheline mosquitoes and malaria transmission around Ziway in the middle courseof the Ethiopian Rift Valley.Design: As a passive experiment, man landing captures were done in homesteads withmixed dwelling, separate cattle shed and without livestock; and as an active experiment,captures were in experimental tukuls (huts) of cattle, goats, and without livestock.Parasite and spleen rates of children were compared among those residents undervariable living conditions mentioned for passive experiment.Subjects: For entomological study, human-baits were used for man-landing captures ofmosquitoes. Study subjects for parasitological and clinical studies were children below10 years old.Main outcome measures: Human-biting rate (HBR) of anopheline mosquitoes; and theparasite and spleen rates of the study subjects in different living conditions.Results: In the passive experiment, the mean HBR of Anopheles arabiensis in mixeddwelling, separate cattle shed and without livestock was 8.45, 4.64 and 5.97, respectively.Similarly, the HBR of An. pharoensis was 2.88, 1.79 and 1.61, respectively. In the activeexperiment, the mean HBR of An. arabiensis in tukuls with cattle, goats, and withoutlivestock was 3.50, 3.38 and 1.43 respectively; while that of An. pharoensis was 0.37,0.70 and 0.55 respectively. Parasitologically, mean parasite rates of 26.67%, 15.05% and23.85% were, respectively, recorded from children living under the above conditionsstated for passive experiment. Similarly, the mean spleen rates of 50.0%, 26.9%, and47.37% were recorded, respectively.Conclusion: These observations in the present study indicate that the presence of cattlein homesteads tends to increase the man biting rate of An. arabiensis, althoughdifferences in the mean HBR of vector mosquitoes were not statistically significant forall groups. In contrast, cattle keeping in separate cattle sheds outside of the humandwellings tends to reduce the man biting rate of An. arabiensis and malaria transmissionin the study area

    Impact of cattle keeping on human biting rate of anopheline mosquitoes and malaria transmission around Ziway, Ethiopia

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    (East African Medical Journal: 2002 79(9): 485-490

    Epidemiology of animal bites and other potential rabies exposures and anti-rabies vaccine utilization in a rural area in Southern Ethiopia

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    The presented report describes the epidemiology of potential rabies exposures and examines the utilization of anti-rabies vaccine in a rural area of Ethiopia during a period of 43 months. A total of 683 persons (51.1% females, 73% children) with animal- related bites were included in the retrospective, registry-based study. The most common site of exposure was the leg (66.8%). In children under 8 years of age the face was more often involved than in adults (9.5% vs. 4.8%; p=0.03). The main type of exposure was a bite with bleeding (66.3%) followed by contamination of mucous membranes with saliva (19.7%). The primary sources were dogs (93.4%) followed by cats (2.6%). Children under 15 years were more likely to be exposed to dogs (94.9%) than adults (88.7%) (p=0.01). The most common way of coming in contact with animals was ‘walking by’ (83.9%). Children came in contact with animals while ‘playing with’ (10.7%) more often than adults (1.1%) (p&amp;amp;lt;0.001). All the patients received an anti-rabies nervous-tissue vaccine, 99% of whom completed the vaccination course. Animal bites continue to be a problem in rural Ethiopia, mainly among children. Efforts to protect children against animal bites must be of paramount importance in preventing rabies in this population
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