55 research outputs found
Echinococcus shiquicus and Echinococcus felidis
Currently, ten genotypes (G1-G10) of Echinococcus Sensu Lato have been explicitly identified on the basis of taxonomic criteria. These include morphometric keys, host specificity, geographical distribution, phylogenetic analysis and genome mapping. However, a few emergent species of genus Echinococcus have been indigenously confirmed in some autonomous regions of Tibet plateau and Africa where there is little known about their biological aspects and potential pathogenicity in intermediate and definitive hosts. This chapter is focused on the parasite history, life cycle, phenotypic aspects, epidemiology, zoonotic potential and phylogeny relationship of two enigmatic parasites namely: Echinococcus shiquicus and Echinococcus felidis. This aims to provide a better understanding of their taxonomic status, public health problems and biological features in the mentioned regions
Frequency of Intestinal Parasites among Zoo Animal by Morphometric Criteria and First Report of the Bivitellobilharzia nairi from Elephant (Elephasmaximus maximus) in Iran
Background: Intestinal parasitic infections are major causative agents of wildlife health complications among different parts of the world. This study aimed to investigate the gastro-intestinal parasites in feces of the zoo animals based on parasitological and morphometric criteria.
Methods: One hundred fresh fecal samples were collected from 35 species of animal lived in Eram park zoo, Tehran, Central Iran during Oct 2015 to Jun 2015. All collected samples were examined by microscopic observation following direct wet mount preparation (normal saline and Lugol's iodine), formalin-ether concentration, and permanent staining. The morphometric aspects of the recovered eggs were surveyed with the aid of Camera Lucida (×400).
Results: 65.7% (23/35) of zoo animal species were infected with intestinal parasites. The superfamily Trichostrongyloidea (6/16) and Strongylus sp. (16/4) were the most prevalent helminthic infections, while Blastocystis sp. (6/14), Entamoeba cyst (3/14) and Eimeria sp. (3/14) were the common protozoan parasites. For the first time, Bivitellobilharzia nairi egg was identified an elephant at Iran. Intestinal parasitic infections were apparently circulating among animals of the Eram park zoo.
Conclusion: Identified parasitic infections can consider as a threatening source to visitors and workers' health that have contact with animals or their feces. Therefore, the effectual preventive strategies should be addressed to determine the risk factors, mechanisms of cross-transmission of parasite, the importance of applying the hygienic practices and well adjusting deworming programs for the animals, zoo workers and visitors
IL-17 and IL-22 elicited by a DNA vaccine encoding ROP13 associated with protection against Toxoplasma gondii in BALB/c mice.
Toxoplasma gondii, an intracellular parasitic protozoan, is capable of infecting man and all warm-blooded animals. Cell-mediated immunity is vital in mounting protective responses against T. gondii infection. Recent studies have shown that T-helper (Th) 17 responses may play a key role in parasite control. In this current study, we constructed a DNA vaccine encoding T. gondii ROP13 in a pcDNA vector. Groups of BALB/c mice were immunized intramuscularly with pcROP13 or controls and challenged with the RH strain of T. gondii. The results showed that immunization with pcROP13 could elicit an antibody response against T. gondii. The expression of the canonical Th17 cytokines, interleukin (IL)-17 and IL-22, were significantly increased after immunization with pcROP13 compared with control groups ( p < 0.05). Furthermore, vaccination resulted in a significant decrease in parasite load ( p < 0.05). The induction of Th17 related cytokines, using a ROP13 DNA vaccine, against T. gondii should be considered as a potential vaccine approach for the control of toxoplasmosis
Screening and molecular characterization of Trichomonas vaginalis genotypes isolated from married women in northern Iran
. Trichomonas vaginalis is an anaerobic protozoan parasite that causes trichomonosis in human. It is one
of the most common non-viral sexually transmitted infections. It has been found to be most prevalent in patients referred
to sexually transmitted disease clinics. In recent years, molecular methods have been used to identify genotypes of this
parasite in different parts of the world and so far 6 types of T. vaginalis have identified. The aim of this study was to
investigate the prevalence and genotype identification of T. vaginalis from married women in northern Iran. A total of
450 vaginal specimens were taken from married women, referring to health centers in northern Iran. Demographic
information of women was collected through a questionnaire. The samples were first examined microscopically and
then monitored in Dorsch culture medium for up to 10 days. Actin genes of positive samples were amplified by PCR.
Finally, PCR products were used to determine the sequence and genotype of the parasite. Overall, 0.7% (3/450) samples
were positive for T. vaginalis. All of the three infected women were housewives. After sequencing, the genotype of these
parasites were type H (66.7%) (Accession no; MW414672-MW414673) and type E (33.3%) (Accession no;
MW414671). Low prevalence of T. vaginalis in north of Iran indicate high level of hygiene in sexual intercourse and
avoiding from high risk sexual behaviors, and also it seems that genotype H is dominant type of the parasite in the study
area
Molecular Identification and Phylogenetic Classification of Leishmania spp. Isolated from Human Cutaneous Leishmaniasis in Iran: A Cross-sectional Study
Background: In Iran, both forms of cutaneous (CL) and visceral leishmaniasis (VL) have been reported; so the accurate species identification of the parasite(s) and the analysis of genetic diversity are necessary.
Methods: The smears were collected from lesions samples of 654 patients with CL, who attended local health centers in 12 provinces of Iran during 2013-2015. The smears were checked for the presence of amastigotes by light microscopy. DNA of 648 Leishmania isolates, amplified by targeting a partial sequence of ITS (18S rRNA–ITS1–5.8S rRNA–ITS2) gene. Twenty-five of all the amplicons were sequenced and analyzed with restriction fragment length polymorphism (RFLP) using the Taq1 enzyme.
Results: All the smears were positive microscopically. The PCR-RFLP analysis revealed that 176 (27%) CL patients were infected with L. tropica and, 478 (73%) with L. major. The dominant species in all over Iran is L. major. The sequencing results of all CL patients and RFLP analysis confirmed each other. Based on our phylogenetic tree, 25 ITS DNA sequences were grouped into two clusters representing L. major and L. tropica species. Phylogenetic tree derived from the ITS sequences supports a clear divergence between L. major from the other species.
Conclusion: Discrimination of Iranian Leishmania isolates using ITS gene gives us this opportunity to detect, identify, and construct the phylogenetic relationship of Iranian isolates
The existence of only one haplotype of Leishmania major in the main and potential reservoir hosts of zoonotic cutaneous leishmaniasis using different molecular markers in a focal area in Iran
Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017
A double burden of malnutrition occurs when individuals, household members or communities experience both undernutrition and overweight. Here, we show geospatial estimates of overweight and wasting prevalence among children under 5 years of age in 105 low- and middle-income countries (LMICs) from 2000 to 2017 and aggregate these to policy-relevant administrative units. Wasting decreased overall across LMICs between 2000 and 2017, from 8.4% (62.3 (55.1–70.8) million) to 6.4% (58.3 (47.6–70.7) million), but is predicted to remain above the World Health Organization’s Global Nutrition Target of <5% in over half of LMICs by 2025. Prevalence of overweight increased from 5.2% (30 (22.8–38.5) million) in 2000 to 6.0% (55.5 (44.8–67.9) million) children aged under 5 years in 2017. Areas most affected by double burden of malnutrition were located in Indonesia, Thailand, southeastern China, Botswana, Cameroon and central Nigeria. Our estimates provide a new perspective to researchers, policy makers and public health agencies in their efforts to address this global childhood syndemic
Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019
Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens
Cryptosporidium infections in terrestrial ungulates with focus on livestock: a systematic review and meta-analysis
BACKGROUND: Cryptosporidium spp. are causative agents of gastrointestinal diseases in a wide variety of vertebrate hosts. Mortality resulting from the disease is low in livestock, although severe cryptosporidiosis has been associated with fatality in young animals. METHODS: The goal of this systematic review and meta-analysis was to review the prevalence and molecular data on Cryptosporidium infections in selected terrestrial domestic and wild ungulates of the families Bovidae (bison, buffalo, cattle, goat, impala, mouflon sheep, sheep, yak), Cervidae (red deer, roe deer, white-tailed deer), Camelidae (alpaca, camel), Suidae (boar, pig), Giraffidae (giraffes) and Equidae (horses). Data collection was carried out using PubMed, Scopus, Science Direct and Cochran databases, with 429 papers being included in this systematic analysis. RESULTS: The results show that overall 18.9% of ungulates from the investigated species were infected with Cryptosporidium spp. Considering livestock species (cattle, sheep, goats, pigs, horses and buffaloes), analysis revealed higher Cryptosporidium infection prevalence in ungulates of the Cetartiodactyla than in those of the Perissodactyla, with cattle (29%) being the most commonly infected farm animal. CONCLUSIONS: Overall, the investigated domestic ungulates are considered potential sources of Cryptosporidium contamination in the environment. Control measures should be developed to reduce the occurrence of Cryptosporidium infection in these animals. Furthermore, literature on wild populations of the named ungulate species revealed a widespread presence and potential reservoir function of wildlife.S
A Review of effectual factors in the Pathogenesis of Leishmania Parasites
Leishmania parasites as the causative agent of leishmaniasis belong to Trypanosomatidae family. Parasite, vector, vertebrate host and environment are major factors in pathogenesis of Leishmania.
Parasite dependent factors are virulence factors which exist in Leishmania species such as LPG, GP63. In recent years, the importance of these factors in the field of vaccine and drug has been considered by researchers. Sand fly biting behavior and salivary gland proteins are vector dependent factors which are effective in the Leishmania pathogenesis. Age, gender, nutrition, immune system, infectious diseases, genetic, occupation, socio-economic characteristics, and habitat are vertebrate host mediated factors. Temperature, rainfall, wind and its speed, soil, and continuous changes in climate are also environmental factors. Therefore the aim of this study was to evaluate the pathogenesis of Leishmania parasites
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