60 research outputs found

    Molecular Diagnosis of Strongyloides stercoralis Infection by PCR Detection of Specific DNA in Human Stool Samples

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    Background: Strongyloidiasis is mostly an asymptomatic infection and diagnosis of latent infec­tions is difficult due to limitations of current parasitological and serological methods. This study was conducted to set up a PCR-based method for molecular diagnosis of Strongyloides stercor­alis infection by detection of copro-DNA in stool samples.Methods: A total of 782 fresh stool samples were collected and examined by agar plate culture. Among those sixteen stool samples, which confirmed to be infected with S. stercoralis were exam­ined as positive control to set up each single and nested PCR, using two primer sets design­ing to amplify partial ribosomal DNA of S. stercoralis genome. Since, single PCR method yielded higher efficacy in detecting positive samples, in the second step, 30 stool samples, which found negative for S. stercoralis by agar plate culture of single stool sample, were examined by sin­gle PCR. Data analysis was performed using McNemar's χ2 test, with consideration of a P-value of <0.05 as indication of significant difference.Results: In amplification of DNA extracted from stool samples, single PCR detected S. stercor­alis DNA target in all 16 positive samples, while nested PCR amplified DNA in only 75% of sam­ples. In the second step, single PCR amplified S. stercoralis extracted DNA in 5 out of 30 sam­ples which were negative by coproculture.Conclusion: Single PCR method amplifying a short (100bp) target represented more efficacies for detection of S. stercoralis in faecal examination compared to agar plate culture and nested PCR, which amplified longer target

    Morphological and Morphometrical Description of Trichostrongylus Species Isolated from Domestic Ruminants in Khuzestan Province, Southwest Iran

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    Backgrounds: Genus Trichostrongylus (Nematoda: Trichostrongylidae) is one of the most impor­tant zoonotic nematodes with wide geographic distribution in the world. The purpose of the present study was to describe morphological and morphometrical characteristics of male Trichostrongylus species, currently prevalent in domestic ruminants of Khuzestan Province, south­west Iran.Methods: Gastro-intestinal organs of 1600 sheep, goats, cattle, and buffalos, slaughtered in Khuzestan Province, southwest Iran, were examined for infectivity with Trichostrongylus spe­cies. For examination and measurements of helminthes, Azo-carmine staining was per­formed, followed by camera lucida drawings of morphological characters and measurements of morphometrical criteria with a calibrated microscope. Using valid nematodes systematic keys, almost all the parasites were identified at the level of species.Results: Overall, 114 animals were found infected with at least one species of Trichostrongy­lus. Considering morphological characteristics of male Trichostrongylus, six species were identi­fied including T. colubriformis, T. vitrinus, T. probolorus, T. capricola, T. longispicu­laris and Trichostrongylus sp. Conclusion: Although, compared to the previous decades, currently Trichostrongylus is much less prevalent in the domestic ruminants of the study area, but still different species occur in these animals

    Seroepidemiological Study of Human Hydatidosis in Meshkinshahr District, Ardabil Province, Iran

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    Background: The aim of this study was to conduct a sero-epidemiological survey in Meshkinshahr, Arda­bil Province, northwestern Iran to detect the rate of hydatidosis in the city and nearby villages. Literature shows that no such study has been conducted so far.Methods: Overall, 670 serum samples were collected from 194 males and 476 females from patients re­ferred to different health centers of the region. All patients filled out a questionnaire and an informed con­sent. Sera were analyzed using indirect-ELISA test. Ten Όg /ml antigens (Antigen B derived from hydatid cyst fluid), serum dilutions of 1:500 and conjugate anti-human coombs with 1:10000 dilutions were util­ized to perform the test. Data analysis was conducted using SPSS software ver. 11.5. Results: The seroprevalence of human hydatidosis was 1.79% by ELISA test in the region. This rate for fe­males was 1.68% and males 2.6%, respectively. There was no significant difference as regards all fac­tors studied and the seropositivity. According to job, farmers and ranchmen had the highest rate of infec­tion as 3.17%. The sero-prevalence of infection was 2.6%% in illiterate people which showed the highest rate. As regards residency, urban life showed no significant difference with rural life (1.1% vs. 2.58%). Age group of 69-90 yr old, with 4.62% as prevalence had the highest rate of positivity.Conclusion: Obtained sero-prevalence of hydatidosis shows more or less a resemblance to other cities of Iran, although due to the specific condition of the city we expected more rate of sero-positivity

    Endoparasites of Rodents and Their Zoonotic Importance in Germi, Dashte–Mogan, Ardabil Province, Iran

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    Background: In order to verify the infectivity of rodents with endoparasites in Germi (Dashte-Mogan, Arda­bil Province) the current study was undertaken.Methods: Using live traps, 177 rodents were trapped during 2005-2007. In field laboratory, all rodents were bled prior to autopsy, frozen at -20°C, and shipped to the School of Public Health, Tehran University of Medical Sciences, Iran. In parasitological laboratory, every rodent was dissected and its different or­gans were examined for the presence of any parasite. Blood thick and thin smears as well as impression smears of liver and spleen were stained with Geimsa and examined microscopically.Results: Two species of rodents were trapped; Meriones persicus (90.4%) and Microtus socialis (9.6%). The species of parasites found in M. persicus and their prevalences were as follows: Hymenolepis di­minuta (38.8%), Hymenolepis nana (2.5%), Trichuris sp.(40.6), Mesocestoides larva (=tetrathyridium) (3.1%), Capil­laria hepatica (6.9%), Moniliformis moniliformis (11.3%), Syphacia obvelata (2.5%), Taenia endotho­racicus larva (0.6%), Physaloptera sp. (0.6%), Dentostomella translucida (0.6%), Heligmosomum mix­tum (0.6%), Strobilocercus fasciolaris (0.6%),and Aspiculuris tetraptera (0.6%). The species of para­sites found in M. socialis and their prevalences were as follows: H. diminuta (17.6%), Trichuris sp. (5.9%), Mesocestoides larva (5.9%), S. obvelata (11.8%), S. syphacia (11.8%), H. mixtum (17.6%), and Aspiculuris tetraptera (11.8%). There were no statistical differences between male and female for infectivity with parasites in either M. persicus or M. socialis. No blood or tissue protozoan parasite was found in any of the rodents examined. Conclusion: Among different species identified, some had zoonotic importance. Therefore, the potential health hazard of these species needs to be considered to prevent infectivity of humans

    Neglected Tropical Diseases of the Middle East and North Africa: Review of Their Prevalence, Distribution, and Opportunities for Control

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    The neglected tropical diseases (NTDs) are highly endemic but patchily distributed among the 20 countries and almost 400 million people of the Middle East and North Africa (MENA) region, and disproportionately affect an estimated 65 million people living on less than US$2 per day. Egypt has the largest number of people living in poverty of any MENA nation, while Yemen has the highest prevalence of people living in poverty. These two nations stand out for having suffered the highest rates of many NTDs, including the soil-transmitted nematode infections, filarial infections, schistosomiasis, fascioliasis, leprosy, and trachoma, although they should be recognized for recent measures aimed at NTD control. Leishmaniasis, especially cutaneous leishmaniasis, is endemic in Syria, Iran, Iraq, Libya, Morocco, and elsewhere in the region. Both zoonotic (Leishmania major) and anthroponotic (Leishmania tropica) forms are endemic in MENA in rural arid regions and urban regions, respectively. Other endemic zoonotic NTDs include cystic echinococcosis, fascioliasis, and brucellosis. Dengue is endemic in Saudi Arabia, where Rift Valley fever and Alkhurma hemorrhagic fever have also emerged. Great strides have been made towards elimination of several endemic NTDs, including lymphatic filariasis in Egypt and Yemen; schistosomiasis in Iran, Morocco, and Oman; and trachoma in Morocco, Algeria, Iran, Libya, Oman, Saudi Arabia, Tunisia, and the United Arab Emirates. A particularly noteworthy achievement is the long battle waged against schistosomiasis in Egypt, where prevalence has been brought down by regular praziquantel treatment. Conflict and human and animal migrations are key social determinants in preventing the control or elimination of NTDs in the MENA, while local political will, strengthened international and intersectoral cooperative efforts for surveillance, mass drug administration, and vaccination are essential for elimination

    Large-scale unit commitment under uncertainty: an updated literature survey

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    The Unit Commitment problem in energy management aims at finding the optimal production schedule of a set of generation units, while meeting various system-wide constraints. It has always been a large-scale, non-convex, difficult problem, especially in view of the fact that, due to operational requirements, it has to be solved in an unreasonably small time for its size. Recently, growing renewable energy shares have strongly increased the level of uncertainty in the system, making the (ideal) Unit Commitment model a large-scale, non-convex and uncertain (stochastic, robust, chance-constrained) program. We provide a survey of the literature on methods for the Uncertain Unit Commitment problem, in all its variants. We start with a review of the main contributions on solution methods for the deterministic versions of the problem, focussing on those based on mathematical programming techniques that are more relevant for the uncertain versions of the problem. We then present and categorize the approaches to the latter, while providing entry points to the relevant literature on optimization under uncertainty. This is an updated version of the paper "Large-scale Unit Commitment under uncertainty: a literature survey" that appeared in 4OR 13(2), 115--171 (2015); this version has over 170 more citations, most of which appeared in the last three years, proving how fast the literature on uncertain Unit Commitment evolves, and therefore the interest in this subject

    "A Simple and Large Scale Performing Protocol for the Detection of Sarcocystis in Muscles of Some Small Mammals"

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    A simple special protocol using Semichon’s acetic carmine stain was applied for examination of muscles of some small mammals, naturally infected with Sarcocystis spp. using this method, infected muscles fibers with Sarcocystis could easily be differentiated from muscle tissues. This method can be applied for screening of infected muscles with Sarcocystis cysts on large number of samples for epidemiological studies, and in slaughterhouses on frozen samples and formalin preserved samples as well as fresh tissues
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