The open tropical medicine journal最新文献

{"title":"Does Silent Giardia Infection Need Any Attention","authors":"Supaluk Popruk, K. Thima, Ruenruetai Udonsom, Pongruj Rattaprasert, Y. Sukthana","doi":"10.2174/1874315301104010026","DOIUrl":"https://doi.org/10.2174/1874315301104010026","url":null,"abstract":"Even though treatment of symptomatic cases as well as improving hygiene and sanitation conditions decrease giardiasis in underdeveloped and/or developing countries, Giardia duodenalis infection is still frequently encountered especially in children living in crowded conditions leading to public health problems. We studied the prevalence of G. duodenalis infection in 274 asymptomatic Thai boy orphans, living in/around the Bangkok metropolitan area, by use of direct fecal smear and formalin-ethyl acetate techniques. This was done to explore our hypothesis that children with asymptomatic giardiasis, who are not likely to be treated, have a high potential for spreading this pathogen. Positive Giardia cases were further genotyped by 2 genes: small subunit ribosomal RNA (ssrRNA) and glutamate dehydrogenase (gdh) to determine the distribution of each G. duodenalis assemblage. Positive G. duodenalis infection was 11.67 % and revealed at 10.63%, 12% and 15%, in PK, TMK, and MHK orphanages, respectively. The overall parasitic infection, including Giardia, was 48.54% consisting mostly of non-pathogenic organisms i.e. Blastocystis hominis, Entamoeba coli, Endolimax nana, Entamoeba histolytica-like, Chilomastix mesnili, Trichuris trichiura, Hymenolepis nana, Strongyloides stercoralis and Hookworm. Fourteen (70 %) and 4 (20 %) out of the 20 positive Giardia samples could be amplified by ssrRNA and gdh genes, respectively; three belonged to the sub-assemblage BIV and only one indicated sub-assemblage AII. Thus children infected with sub-assemblage BIV isolate are more common in this study. In conclusion, we focused on asymptomatic giardiasis children, hitherto unrecognized, who consistently contaminate their environments with cysts. We favor not only treating these children to eradicate the source of the infection, but also to encourage an active surveillance program consisting of highly sensitive methods to identify silent giardiasis cases. In addition to these 2 strategies, a continuous fruitful health education program for all stakeholders is another crucial tool. These actions will benefit the control of human giardiasis and reduce public health problems.","PeriodicalId":88762,"journal":{"name":"The open tropical medicine journal","volume":"4 1","pages":"26-32"},"PeriodicalIF":0.0,"publicationDate":"2011-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68068397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From Asia, the Novel (and Old) Fifth Malaria Plasmodium of Human Beings","authors":"S. Sabbatani, S. Fiorino, R. Manfredi","doi":"10.2174/1874315301104010021","DOIUrl":"https://doi.org/10.2174/1874315301104010021","url":null,"abstract":"A novel form of human malaria Plasmodium knowlesi has been identified in small epidemic foci occurred during the last decade in Malaysia. Based on a review of the available literature data, the Authors underline the diagnostic importance of molecular biology examinations performed with primers which are specific of Plasmodium knowlesi, since the standard hemoscopy may fail in distinguishing Plasmodium knowlesi from Plasmodium malariae, due to their similar appearance. P. knowlesi has been reported as a causative parasite agent of life-threatening and even lethal forms of malaria. In humans, its clinical picture is more severe a compared to that of P. malariae, since the disease is characterized by a greater parasitemia, versus that is referred in the course of P. malariae disease. The most effective carrier of P. knowlesi is represented by the mosquito Anopheles leucosphyrus, which is attracted by both humans and monkeys. Among primates, the natural hosts of P. Knowlesi are known until now and have been represented by Macaca fascicularis and Macaca nemestina, while other monkeys including Saimiri scirea and Macaca mulatta, which cannot become infected. These might be useful in eventual experimental models. When facing the potentially severe evolution of human disease by P. knowlesi, we remark the key role played by a prompt disease recognition, which is expected to be more easy and obvious in patients followed in endemic countries at elevate risk, but should be carefully implemented for subjects coming back to health care services of western countries, presenting with a number of typical signs and symptoms of malaria, after travelling in South-East Asia where they were engaged in staying or making excursions in the tropical forest. In these last cases, both diagnosis and treatment should be prompt, timely, and appropriate. According to literature data, in non-severe human cases the old and trivial chloroquine remained very effective against P. knowlesi, achieving the disappearance of signs and symptoms in 96% of cases within the first day of pharmacological therapy. On the ground of the emerging epidemiological figures, P. knowlesi was added to Plasmodium vivax, Plasmodium ovale, Plasmodium malariae, and Plasmodium falciparum, as the fifth etiological agent of human malaria. During the next years, it will become mandatory to plan an adequate surveillance programme of the epidemiological evolution of this novel form of human malaria, paying also maximum attention to the clinical presentation of patients affected by P. knowlesi malaria, which are expected to suffer from a more severe clinical course, according to the time elapsed from the appearance of the early signs and symptoms. Some preliminary clinical figures suggest that a greater severity is related to an increased parasitemia, and parallels the increased interhuman infectious passages of parasites.","PeriodicalId":88762,"journal":{"name":"The open tropical medicine journal","volume":"23 1","pages":"21-25"},"PeriodicalIF":0.0,"publicationDate":"2011-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68068388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic Diversity in Dengue Mosquito, Aedes aegypti (Diptera: Culicidae) from Amazon Region: Comparative Analysis with Isozymes and RAPD Loci","authors":"J. M. Santos, E. Fraga, J. D. F. Maia, W. Tadei","doi":"10.2174/1874315301104010011","DOIUrl":"https://doi.org/10.2174/1874315301104010011","url":null,"abstract":"Four populations of Aedes aegypti from Manaus were studied, using allozymes and RAPD loci, to determine intra- and interpopulation genetic variability and differentiation and to compare genetic structure parameters assessed with both markers. Five RAPD primers produced 52 polymorphic fragments, whereas only seven of 18 isozyme loci were polymorphic. The population from Praca 14 was the most polymorphic (P= 94.23% and P= 55.6%); while those from Coroado (P= 82.69% and P= 44.40%) and from Cidade Nova (P= 84.61% and P= 44.40%) were the least polymorphic, for both RAPD and isozymes respectively. The observed heterozygosity was higher between populations (Ho= 0.33 - 0.38) as assessed by RAPD. Wright's F statistics showed an F is value higher than F st (F is = 0.164 > F st = 0.048). AMOVA indicated that 95.12% of the genetic variability is intrapopulational. Even so, both of the genetic markers evaluated showed a relatively high gene flow ((N m = 15.15), and possibly are still random couplings, although the F is value was not low. The genetic distance between populations was similarly low for both markers: RAPD (0.012 - 0.016) and Isozymes (0.003 - 0.016). These results show that as assessed by both markers, the populations are genetically similar, and that isozymes (codominant) are the most efficient to detect the population genetic structure. Although isozymes revealed less genetic diversity than RAPDs, the estimated levels of genetic distance were identical.","PeriodicalId":88762,"journal":{"name":"The open tropical medicine journal","volume":"4 1","pages":"11-14"},"PeriodicalIF":0.0,"publicationDate":"2011-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68068381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simple and Direct Characterization of Leishmania donovani Isolates Based on Cytochrome Oxidase II Gene Sequences","authors":"A. Sharief, E. Khalil, D. Barker, S. Omer, H. Abdalla, M. Ibrahim","doi":"10.2174/1874315301104010001","DOIUrl":"https://doi.org/10.2174/1874315301104010001","url":null,"abstract":"We primarily identified Leishmania donovani parasites from eastern Sudan using species-specific primers that amplify a whole length minicircle. Based on the amplification of a cytochrome oxidase II fragment (COII), heteroduplex analysis (HDA) was performed. In HDA, the appearance of the extra bands with molecular weights higher than 540 bp indicates the presence of mismatched bases in the selected samples. Such bands were detected when hybridization was between reference strains and clinical isolates, as well as between the reference strains themselves, while no heteroduplexes were detected between the clinical isolates. Moreover, an RFLP assay using the restriction enzyme Ssp1 was performed on the original 540 bp products to discern an A-G transition, which differentiates between members of the Leishmania (L) infantum and those of Leishmania (L) donovani subspecies. The proposed minicircle genes-based analysis was rapid and easy to perform method for the characterization of Leishmania donovani complex isolates and with a potential to be extended to characterization of other species of Leishmania.","PeriodicalId":88762,"journal":{"name":"The open tropical medicine journal","volume":"4 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2011-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68068317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pregnancy-Associated Malaria in Sudan: Prevalence and Possible Risk Factors","authors":"S. Omer, E. Khalil, A. Sharief, H. Ali","doi":"10.2174/1874315301104010006","DOIUrl":"https://doi.org/10.2174/1874315301104010006","url":null,"abstract":"This study aimed to investigate the malaria infection prevalence and predisposing risk factors among some pregnant women in Greater Khartoum area, Sudan. Following informed consent, eight hundred thirty six pregnant women were interviewed and thick blood films were prepared and examined for malaria parasites. Parasite densities were determined by counting parasites against 200 leukocytes assuming a white blood cells count of 6,000/µl. PCR was performed using outer and nested primers to enhance detection of parasitemia below the microscopy threshold, after DNA extraction by chelex method. Microscopy and species-specific PCR results showed that 26.2% and 56.5% of women were positive respectively. Low parity and young-aged pregnant women were significantly associated with parasitemia (p=0.001, 0.004). Second trimester pregnancy (adjusted odd ratio (aOR), 3.2 (95% CI, 2.9-5.8,)) and season of antenatal visit ((aOR), 1.7 (95% CI, (0.9-1.1)) constituted a significant risk factor for contracting malaria. In a multivariate analysis, mothers <20 years ((aOR), 2.4 (95% CI, 1.3-3.0)), first and second pregnancies ((aOR), 2.0 (95% CI, 1.1-1.9)), poverty- related factors (low-income, illiteracy) were independent predictors for P. falciparum infection. Pregnancy-associated P. falciparum malaria is prevalent among Sudanese pregnant women with evidence of close correlation to low parity, young age and socioeconomic status.","PeriodicalId":88762,"journal":{"name":"The open tropical medicine journal","volume":"4 1","pages":"6-10"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68068375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic Diversity of Plasmodium falciparum Strains in Children under Five Years of Age in Southeastern Tanzania","authors":"Deborah Sumari, K. Hosea, J. Mugasa, S. Abdulla","doi":"10.2174/1874315301003010010","DOIUrl":"https://doi.org/10.2174/1874315301003010010","url":null,"abstract":"Strain diversity may play a role in delaying development of protective immunity in endemic areas. We evaluated genetic diversity of Plasmodium falciparum infected children before being treated with Sulphadoxine Pyrimethamine (SP) and Coartem™ in Southeastern Tanzania. Allelic diversity of P. falciparum strains were determined in order to further assist in correct estimation of recrudescent and new infections. P. falciparum isolated from 300 children aged 1-59 months was used in the study, where nested PCR followed by Restriction Fragment Length Polymorphism (RFLP) of highly polymorphic Merozoite surface protein 2 (msp2) was employed to understand the genetic diversity of the parasites population. Frequency of msp2 gene alleles was calculated and further associated with multiplicity of infection of children under five years of age. A total of 71 and 83 different msp2 alleles were found in Rufiji and Ulanga districts respectively. Children infected with either FC27 or 3D7 allelic type in Rufiji were 42% single, 55.3% double and 2.7% triple, while in Ulanga, 36.7% single, 62% double and 1.3% triple infections. Mean numbers of multiplicity of infections (MOI) in Rufiji and Ulanga were 1.6 and 1.3, respectively. These findings show a high genetic diversity of P. falciparum strains in study areas and low MOI could reflect production of susceptible parasites that immune response can accommodate or can be cleared by the drugs. Furthermore, 3D7 allelic type of msp2 gene was more prevalent than FC27 in Ulanga district, indicating association between msp2 allelic type and disease severity, hence predict possible vaccine candidate in the future.","PeriodicalId":88762,"journal":{"name":"The open tropical medicine journal","volume":"3 1","pages":"10-14"},"PeriodicalIF":0.0,"publicationDate":"2010-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68068219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Co-existence of Dihydrofolate Reductase (dhfr108) Gene with Plasmodium falciparum Chloroquine Resistance Transporter Gene (Pfcrt T76) in P. falciparum Isolates from Gezira State, Central Sudan","authors":"O. Omer, A. Tahir, M. Abdelwahid, N. Gasmelseed, A. Mergani, N. Elwali","doi":"10.2174/1874315301003010015","DOIUrl":"https://doi.org/10.2174/1874315301003010015","url":null,"abstract":"Malaria parasite multi-drug resistance poses serious health problems in tropical countries. The aim of this study was to assess the Sulfadoxine-pyrimethamine (S/P) resistance of Plasmodium falciparum parasite in central Sudan, using the molecular markers. The genotying of P. falciparum parasite from forty-four patients using RFLP and PCR showed that the polymorphism of dhfr gene was in codons 51, 59 and 108. In codon 51; two strains (4.5%) were mutant type; 3 (6.8%) were found as mixed infection (both mutant and wild types) and 28 (63.6%) were found as wild type. One sample (2.2 %) was dhfr 59 mutant and 31 (70.4. %) were wild type, while 14 (31.8%) were dhfr 108 mutant; three (6.8%) were found as mixed infection and 24 (54.5%) were wild types. The Screening of dhps 540 polymorphisms of the gene revealed that 2 (4.5%) were found as mixed infection, and 42 (95.5%) as wild type. Fifteen samples were analyzed for Pfcrt T76, and Pfmdr-1 Y 86 for CQ resistant polymorphisms from the current study, the result showed that 33.3% were found to be mutant at dhfr 108 and PfcrtT76 genes reflecting the link between dhfr108 and Pfcrt76 genes. In conclusion, the polymorphism in the dhfr and dhps genes in central Sudan are increasing, but less abundant compared to the neighboring countries. However, the current studies indicate the link between dhfr108 and Pfcrt76 genes. Therefore, further study is need for using the S/P in areas that confirmed with chloroquine resistant strains.","PeriodicalId":88762,"journal":{"name":"The open tropical medicine journal","volume":"3 1","pages":"15-17"},"PeriodicalIF":0.0,"publicationDate":"2010-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68068294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applications of Nanomedicine in Antibacterial Medical Therapeutics and Diagnostics","authors":"Liam Matthews, R. Kanwar, Shun-Feng Zhou, V. Punj, J. Kanwar","doi":"10.2174/1874315301003010001","DOIUrl":"https://doi.org/10.2174/1874315301003010001","url":null,"abstract":"The need for new and effective/efficient antibacterial therapeutics and diagnostics is necessary if we want to be able to maintain and improve the protection against pathogenic bacteria. Bacteria are becoming increasingly resistant to traditionally used antibiotics and as a result are a major health concern. The number of deaths and hospitalizations due to bacteria is increasing. Current methods of bacterial diagnostics are inefficient as they lack speed and ultra sensitivity and cannot be performed on site. This is where nanomedicine is playing a vital role. The discovery of new and innovative materials through the improvement in fabrication techniques has seen the establishment of an influx of novel antibacterial therapeutics and diagnostics. The goal of this review is to highlight the research that has been done through the implementation of nanomaterials and nanotechnologies for antibacterial medical therapeutic and diagnostic.","PeriodicalId":88762,"journal":{"name":"The open tropical medicine journal","volume":"3 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2010-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68068213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization and treatment of severe malaria in hospitalized children at a Ghanaian district hospital.","authors":"R. Gyapong, M. Duwiejua, F. Bio, E. Woode, C. Ansah, F. Owusu-Daaku, K. Buabeng","doi":"10.2174/1874315300902010039","DOIUrl":"https://doi.org/10.2174/1874315300902010039","url":null,"abstract":"Objective: To document the demography of paediatric admissions due to severe malaria, presentation and determinants of clinical symptoms and treatment for the condition at the KNUST Hospital, Ghana. Methods: A prospective, non-randomized, observational study was undertaken at the Children's Ward of the KNUST Hospital, in Kumasi. During a one month period, the symptoms on admission, treatment and treatment outcome of included children were documented. Inclusion criteria were age 0-144 months, verbal informed consent and severe malaria defined by presence of asexual Plasmodium falciparum parasitaemia coupled with at least one criterion suggestive of severe malaria as defined by WHO. Results: Overall, there were 82 malaria admissions with 69 cases being enrolled. On admission, mean haemoglobin levels were consistent for both males and females. Mean body weight was higher for females. Main presentations were anaemia of moderate to severe form (56); fever (52) and convulsions (24). Prostration was observed in all cases. Children under 5 years of age were associated with anaemia (p=0.018) and neurological symptoms (p=0.003). Clinical presentation of severe malaria was found to be independent of patients' sex. Quinine was used as treatment in 17 cases; monotherapy with artemisinin derivatives in 26 cases and artemisinin-amodiaquine combinations in 19 of the cases. No deaths were recorded. Conclusions: Children under 5 years of age presented more often with severe malaria. Prostration, anaemia and neurological symptoms were the most frequent manifestations.","PeriodicalId":88762,"journal":{"name":"The open tropical medicine journal","volume":"2 1","pages":"39-44"},"PeriodicalIF":0.0,"publicationDate":"2009-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68068204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence of Exclusively Right-Sided Endomyocardial Fibrosis among Patients with Heart Failure in Equatorial Guinea","authors":"M. Gergana, Hazanov Eivgeny, Neuberger Ami, Garcia Maria Cecilia, C. Dario, Stamler Alon","doi":"10.2174/1874315300902010024","DOIUrl":"https://doi.org/10.2174/1874315300902010024","url":null,"abstract":"Endomyocardial fibrosis (EMF) is a common restrictive cardiomyopathy of unknown etiology, endemic to regions close to the equator. According to previously published reports, the disease affects only the right ventricle (RV) 10-28% of patients with endomyocardial fibrosis. The aims of this study were to determine the prevalence of EMF among patients with heart failure in Equatorial Guinea, and to describe its clinical manifestations. We used transthoracic echocardiography to determine the prevalence of EMF among 50 patients with newly diagnosed heart failure. We compared the demographic data, clinical features and eosinophilic counts in patients with EMF and patients with other forms of heart failure. During a study period of nine months ten patients were diagnosed with EMF, accounting for 20% of the patients diagnosed with heart failure. Curiously, all ten patients had exclusive right-sided disease. The average time from the onset of symptoms to diagnosis was 6.1±2.0 years (range 3-9 years), implicating a much better prognosis than previously reported. Eosinophil count was not higher in patients with EMF when compared to other patients with heart failure. The exclusive involvement of the right ventricle in ten consecutive patients, and the relatively long survival after the onset of symptoms, hint towards a specific variant of the disease in Equatorial Guinea.","PeriodicalId":88762,"journal":{"name":"The open tropical medicine journal","volume":"2 1","pages":"24-26"},"PeriodicalIF":0.0,"publicationDate":"2009-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68068138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}