41 research outputs found
Short communication: Monogenean species from freshwater fishes of Zanjan province, Iran
This parasitological research was conducted from September 2002 to August 2003 on the freshwater fishes in Zanjan province. Totally 155 fishes including Capoeta capoeta idellaI (91), Carassius auratus (8), Leuciscus cephalus (18), Ctenopharyngodon idella (10), Barbus lacerta (8), Allburnoides bipunctatus (10) and Alburnus filippi (10), were seined from five different stations. The fishes were transferred to Laboratory of Aquatic Organisms Research in Science Faculty of Shahid Beheshti University. The skin and gills of fishes were studied under light and stereomicroscope. The identified monogenean parasites included seven Dactylogyrus species as: D. chramuli, D. gracilis, D. Lenkorani and D. pulcher from Capoeta capoeta gracilis; D. lamellatus from Ctenopharyngodon idella; D. goktschaicus from Barbus lacerta and D. vistulae from Albunoides bipunctatus and Alburnus filippi. Various Gyrodactylus spp. from skin and gills of different fish specimens and one Paradiplozoon sp. from gill of Alburnoides bipunctatus were observed. This is the first parasitological investigation that has been done on the freshwater fishes of Zanjan province
Gonads tissue changes of Chalcalburnus mossulensis (Heckel, 1843) infected by Ligula intestinalis (Cestoda)
Chalcalburnus mossulensis from the cyprinidae family is one of the indigenous fish in Gheshlagh Lake of Kordestan, Iran. Ligula intestinalis is one of the infective parasites among various species of fish and causes gonads atrophy. In this study, after detection of species and age of samples, the effects of this parasite on gonads tissues and sexual maturation of Chalcalburnus mossulensis were investigated. By seasonal sampling 144 samples were collected. After investigatiing gonad tissue samples, it was clear that, there is a significant difference between the means of male and female gonads maturation rate in infected and non infected samples (p< 0.05). Infection by Ligula intestinalis can be the reason for lack of gonads maturation. In addition, the abnormal degenerative changes like, absorption follicle, hemorrhage and infiltration of inflammation cells in ovary tissues of infected fish were seen. In testicle tissue, dispersed hemorrhage, atrophy and MMC (melano-macrophage center) were seen as pathological signs. So the spread of this parasite in different water sources is important as the point the maintenance of native species and cultivated fish
Detection and identification of white spot syndrome virus (WSSV) and infectious hypodermal and hematopoietic necrosis virus (IHHNV) of Litopenaus vannamei from Bushehr and Sistan and Baloochestan provinces (Iran), during 2009-2010
The first time the white spot disease (WSD) and IHHNV were reported in Iran was in 2004 and 2008, respectively in Bushehr Province. In Sistan and Balochestan province only the WSD was reported in 2008.The aim of this study was detecting these two viral diseases in these provinces, during December 2009 to April 2010. A total of 364 samples were collected according to suspected gross signs from hatcheries and shrimp farms in Bushehr and Sistan and Blochestan provinces (I.R. Iran) respectively, including larvae (72, 43 samples), post larvae (48, 37 samples), juveniles (57, 32 samples), sub adults (39, 22 samples) and broodstock (29, 13 samples) of Litopenaus vannamei . WSD was detected from juveniles (23 samples), sub adults (14 samples), and broodstock (14 samples), and IHHNV was also detected from juveniles (16 samples), sub adults (9 samples) and broodstock (5 samples) based on gross signs, PCR and histopathological changes from Bushehr province but from Sistan and Blochestan province only WSD was detected from juveniles (26 samples), sub adults (18 samples) and broodstock (7 samples). Histopathological observations of WSSV showed basophilic Cowdry type A inclusion bodies in all tissues such as gills, haematopoietic tissue, cuticle epithelium, lymphoid organ and connective tissue. However histologically, the hepatopancreas tissue showed vacuolization of B cells , without inclusion bodies, but histopatholgical changes caused IHHNV including eosinophilic Cowdry type A inclusion bodies which were ectodermal, mesodermal and rarely endodermal
Survey on fungal, parasites and epibionts infestation on the Astacus leptodactylus (Eschscholtz, 1823), in Aras Reservoir West Azarbaijan, Iran
A total of 394 (255 males, 139 females) live freshwater crayfish Astacus leptodactylus from four stations of Aras reservoir in West Azarbaijan Province (North-Western Iran) were studied during the winter until early autumn of 2009 for the presence of parasites, epibionts and fungal agents. Parasitological surveys were carried out on gills, exoskeleton and internal organs, mycological examinations on the exoskeleton (the legs, abdominal cuticle and the eggs). 9 epibionts and parasites peritrich protozoans including: Cothurnia sieboldii (68.5%), Zoothamnium spp. (56.6%), Vorticella similis (45.6%), Chilodonella spp. (0.5%), Podophrya fixa (7.8%), Epistylis chrysemidis (53.2%), Pyxicola annulata (66%), Opercularia articulata (19.8%), Tetrahymena pyriformis (0.5%) were recorded. From Metazoan parasites group, Branchiobdella kozarovi (71%) as the first observation was the only parasite recorded from exoskeleton with prevalence (100%) during spring and summer of the study year. Infected gills were heavily damaged with Aeolosoma hemprichi (Annelid) in winter with 90% prevalence. Other epibiont fouling organisms such as Rotatoria, free living Nematods were observed in this survey. Furthermore, on the mycotic agents identified Penicillium expansum, Aspergillus flavus, Alternaria sp., Fusarium sp. and Saprolegnia sp. were isolated in IM media and identified with slides cultured from cuticular melanized lesions and eggs of infected specimens. This is the first investigation on epibionts, parasites and fungal organisms of the endemic crayfish in Aras reservoir, Iran
Mapping geographical inequalities in childhood diarrhoeal morbidity and mortality in low-income and middle-income countries, 2000–17 : analysis for the Global Burden of Disease Study 2017
Background
Across low-income and middle-income countries (LMICs), one in ten deaths in children younger than 5 years is attributable to diarrhoea. The substantial between-country variation in both diarrhoea incidence and mortality is attributable to interventions that protect children, prevent infection, and treat disease. Identifying subnational regions with the highest burden and mapping associated risk factors can aid in reducing preventable childhood diarrhoea.
Methods
We used Bayesian model-based geostatistics and a geolocated dataset comprising 15 072 746 children younger than 5 years from 466 surveys in 94 LMICs, in combination with findings of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, to estimate posterior distributions of diarrhoea prevalence, incidence, and mortality from 2000 to 2017. From these data, we estimated the burden of diarrhoea at varying subnational levels (termed units) by spatially aggregating draws, and we investigated the drivers of subnational patterns by creating aggregated risk factor estimates.
Findings
The greatest declines in diarrhoeal mortality were seen in south and southeast Asia and South America, where 54·0% (95% uncertainty interval [UI] 38·1–65·8), 17·4% (7·7–28·4), and 59·5% (34·2–86·9) of units, respectively, recorded decreases in deaths from diarrhoea greater than 10%. Although children in much of Africa remain at high risk of death due to diarrhoea, regions with the most deaths were outside Africa, with the highest mortality units located in Pakistan. Indonesia showed the greatest within-country geographical inequality; some regions had mortality rates nearly four times the average country rate. Reductions in mortality were correlated to improvements in water, sanitation, and hygiene (WASH) or reductions in child growth failure (CGF). Similarly, most high-risk areas had poor WASH, high CGF, or low oral rehydration therapy coverage.
Interpretation
By co-analysing geospatial trends in diarrhoeal burden and its key risk factors, we could assess candidate drivers of subnational death reduction. Further, by doing a counterfactual analysis of the remaining disease burden using key risk factors, we identified potential intervention strategies for vulnerable populations. In view of the demands for limited resources in LMICs, accurately quantifying the burden of diarrhoea and its drivers is important for precision public health
Five insights from the Global Burden of Disease Study 2019
The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 provides a rules-based synthesis of the available evidence on levels and trends in health outcomes, a diverse set of risk factors, and health system responses. GBD 2019 covered 204 countries and territories, as well as first administrative level disaggregations for 22 countries, from 1990 to 2019. Because GBD is highly standardised and comprehensive, spanning both fatal and non-fatal outcomes, and uses a mutually exclusive and collectively exhaustive list of hierarchical disease and injury causes, the study provides a powerful basis for detailed and broad insights on global health trends and emerging challenges. GBD 2019 incorporates data from 281 586 sources and provides more than 3.5 billion estimates of health outcome and health system measures of interest for global, national, and subnational policy dialogue. All GBD estimates are publicly available and adhere to the Guidelines on Accurate and Transparent Health Estimate Reporting. From this vast amount of information, five key insights that are important for health, social, and economic development strategies have been distilled. These insights are subject to the many limitations outlined in each of the component GBD capstone papers.Peer reviewe
Mapping 123 million neonatal, infant and child deaths between 2000 and 2017
Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations
Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950-2019 : a comprehensive demographic analysis for the Global Burden of Disease Study 2019
Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019.
Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2·72 (95% uncertainty interval [UI] 2·66–2·79) in 2000 to 2·31 (2·17–2·46) in 2019. Global annual livebirths increased from 134·5 million (131·5–137·8) in 2000 to a peak of 139·6 million (133·0–146·9) in 2016. Global livebirths then declined to 135·3 million (127·2–144·1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2·1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27·1% (95% UI 26·4–27·8) of global livebirths. Global life expectancy at birth increased from 67·2 years (95% UI 66·8–67·6) in 2000 to 73·5 years (72·8–74·3) in 2019. The total number of deaths increased from 50·7 million (49·5–51·9) in 2000 to 56·5 million (53·7–59·2) in 2019. Under-5 deaths declined from 9·6 million (9·1–10·3) in 2000 to 5·0 million (4·3–6·0) in 2019. Global population increased by 25·7%, from 6·2 billion (6·0–6·3) in 2000 to 7·7 billion (7·5–8·0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58·6 years (56·1–60·8) in 2000 to 63·5 years (60·8–66·1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019
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