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1.
Trop Med Infect Dis ; 9(4)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38668533

RESUMO

OBJECTIVE: This study aimed to improve dengue fever predictions in Singapore using a machine learning model that incorporates meteorological data, addressing the current methodological limitations by examining the intricate relationships between weather changes and dengue transmission. METHOD: Using weekly dengue case and meteorological data from 2012 to 2022, the data was preprocessed and analyzed using various machine learning algorithms, including General Linear Model (GLM), Support Vector Machine (SVM), Gradient Boosting Machine (GBM), Decision Tree (DT), Random Forest (RF), and eXtreme Gradient Boosting (XGBoost) algorithms. Performance metrics such as Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and R-squared (R2) were employed. RESULTS: From 2012 to 2022, there was a total of 164,333 cases of dengue fever. Singapore witnessed a fluctuating number of dengue cases, peaking notably in 2020 and revealing a strong seasonality between March and July. An analysis of meteorological data points highlighted connections between certain climate variables and dengue fever outbreaks. The correlation analyses suggested significant associations between dengue cases and specific weather factors such as solar radiation, solar energy, and UV index. For disease predictions, the XGBoost model showed the best performance with an MAE = 89.12, RMSE = 156.07, and R2 = 0.83, identifying time as the primary factor, while 19 key predictors showed non-linear associations with dengue transmission. This underscores the significant role of environmental conditions, including cloud cover and rainfall, in dengue propagation. CONCLUSION: In the last decade, meteorological factors have significantly influenced dengue transmission in Singapore. This research, using the XGBoost model, highlights the key predictors like time and cloud cover in understanding dengue's complex dynamics. By employing advanced algorithms, our study offers insights into dengue predictive models and the importance of careful model selection. These results can inform public health strategies, aiming to improve dengue control in Singapore and comparable regions.

2.
Infect Dis Poverty ; 12(1): 97, 2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37845775

RESUMO

BACKGROUND: Clonorchis sinensis, one of the most important food-borne zoonotic trematodes, remains prevalent in China. Understanding its infection status in animals is crucial for controlling human clonorchiasis. Here we conducted a systematic review and meta-analysis to focus on the spatio-temporal disparities of C. sinensis infection in animals in China. METHODS: Data on C. sinensis prevalence in snails, the second intermediate hosts, or animal reservoirs in China were extracted from electronic databases including PubMed, Embase, Web of Science, Chinese Wanfang database, CNKI, VIP, and China Biomedical Literature database. A random-effects meta-analysis model was utilized to estimate the pooled prevalence in each of the above animal hosts. Subgroup analysis and multivariable meta-regression were performed to explore potential sources of heterogeneity across studies and compare the temporal disparity of infection rates between high and low epidemic areas. Scatter plots were used to depict the biogeographical characteristics of regions reporting C. sinensis infection in animals. RESULTS: The overall pooled prevalence of C. sinensis was 0.9% (95% CI: 0.6-1.2%) in snails, 14.2% (12.7-15.7%) in the second intermediate host, and 14.3% (11.4-17.6%) in animal reservoirs. Prevalence in low epidemic areas (with human prevalence < 1%) decreased from 0.6% (0.2-1.2%) before 1990 to 0.0% (0.0-3.6%) after 2010 in snails (P = 0.0499), from 20.3% (15.6-25.3%) to 8.8% (5.6-12.6%) in the second intermediate hosts (P = 0.0002), and from 18.3% (12.7-24.7%) to 4.7% (1.0-10.4%) in animal reservoirs. However, no similar decrease in prevalence was observed in high epidemic areas (with human prevalence ≥ 1.0%). C. sinensis infections were predominantly reported in areas with altitudes below 2346 m and annual cumulative precipitation above 345 mm and were mostly concentrated in eastern China. CONCLUSIONS: There are spatio-temporal disparities in the animal infections of C. sinensis in different areas of China. Animal infections are primarily concentrated in regions with low altitude and high precipitation. The results suggest that implementing One Health-based comprehensive measures targeting both humans and animals, especially in high epidemic areas, is essential for successful eradication of C. sinensis in China.


Assuntos
Clonorquíase , Clonorchis sinensis , Animais , Humanos , Clonorquíase/epidemiologia , Clonorquíase/veterinária , China/epidemiologia , Prevalência , Caramujos
3.
Trop Med Infect Dis ; 8(3)2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36977133

RESUMO

Background: Zoonotic Babesia infections are an emerging public health threat globally. The geographical distribution, animal reservoirs and tick vectors vary greatly across Babesia species, and estimations of prevalence reported in works within the literature are also quite different. Better prevalence estimates and identification of moderators are needed to understand the global transmission risk of different zoonotic Babesia species, and to provide crucial background information for the diagnosis, treatment and control of zoonotic babesiosis. Methods: We conducted a systematic review and meta-analysis to determine the global nucleic acid prevalence of different zoonotic Babesia species in humans, animals and ticks. Relevant publications were obtained from several electronic databases and grey literature up to December 2021. Articles were included if they were published in English or Chinese and reported the nucleic acid prevalence of zoonotic Babesia species in humans, animals or ticks. The pooled estimates of prevalence were determined using a random effect model. Heterogeneity was investigated using subgroup analyses and random effect meta-regression models. Results: Of 3205 unique studies, 28 were included by the systematic review of zoonotic Babesia for humans, 79 for animals and 104 for ticks. The results showed overall pooled estimates of nucleic acid prevalence for the following: B. microti-1.93% (0.32-4.69%) in humans; B. microti-7.80% (5.25-10.77%), B. divergens-2.12% (0.73-4.08%) and B. venatorum-1.42% (0.30-3.16%) in animals; and B. microti-2.30% (1.59-3.13%), B. divergens-0.16% (0.05-0.32%), and B. venatorum-0.39% (0.26-0.54%) in questing ticks. The type of population, animal reservoir or tick vector, detecting method and continent were moderators possibly associated with heterogeneity, yet the remaining heterogeneity that was not explained was still substantial (all QE p values < 0.05). Conclusions:B. microti is the most prevalent and widely distributed zoonotic Babesia species globally. The wide range of suitable animal reservoirs and potential transmission vectors and high prevalence in animals and ticks may contribute to the worldwide distribution of B. microti. Other zoonotic Babesia species were relatively less prevalent and were reported in quite limited areas.

4.
Parasit Vectors ; 15(1): 363, 2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36221118

RESUMO

BACKGROUND: Snail control is critical to schistosomiasis control efforts in China. However, re-emergence of Oncomelania hupensis is challenging the achievements of schistosomiasis control. The present study aimed to test whether the amphibious snails can spread across watersheds using a combination of population genetics and geographic statistics. METHODS: The digital maps and attributes of snail habitats were obtained from the national survey on O. hupensis. Snail sampling was performed in 45 counties of Sichuan Province. The cox1 gene of specimens was characterized by sequencing. Unique haplotypes were found for phylogenetic inference and mapped in a geographical information system (GIS). Barriers of gene flow were identified by Monmonier's maximum difference algorithm. The watercourses and watersheds in the study area were determined based on a digital elevation model (DEM). Plain areas were defined by a threshold of slope. The slope of snail habitats was characterized and the nearest distance to watercourses was calculated using a GIS platform. Spatial dynamics of high-density distributions were observed by density analysis of snail habitats. RESULTS: A total of 422 cox1 sequences of O. hupensis specimens from 45 sampling sites were obtained and collapsed into 128 unique haplotypes or 10 clades. Higher haplotype diversity in the north of the study area was observed. Four barriers to gene flow, leading to five sub-regions, were found across the study area. Four sub-regions ran across major watersheds, while high-density distributions were confined within watersheds. The result indicated that snails were able to disperse across low-density areas. A total of 63.48% habitats or 43.29% accumulated infested areas were distributed in the plain areas where the overall slope was < 0.94°. Approximately 90% of snail habitats were closer to smaller watercourses. Historically, high-density areas were mainly located in the plains, but now more were distributed in hilly region. CONCLUSIONS: Our study showed the cross-watershed distribution of Oncomelania snails at a large scale. Natural cross-watershed spread in plains and long-distance dispersal by humans and animals might be the main driver of the observed patterns. We recommend cross-watershed joint control strategies for snail and schistosomiasis control.


Assuntos
Gastrópodes , Esquistossomose , Animais , China/epidemiologia , Ecossistema , Humanos , Filogenia , Schistosoma , Esquistossomose/epidemiologia
5.
Trop Med Infect Dis ; 7(8)2022 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-36006272

RESUMO

BACKGROUND: Dengue has become one of the major vector-borne diseases, which has been an important public health concern. We aimed to estimate the disease burden of dengue in major endemic regions from 1990 to 2019, and explore the impact pattern of the socioeconomic factors on the burden of dengue based on the global burden of diseases, injuries, and risk factors study 2019 (GBD 2019). METHODS: Using the analytical strategies and data from the GBD 2019, we described the incidence and disability-adjusted life years (DALYs) of dengue in major endemic regions from 1990 to 2019. Furthermore, we estimated the correlation between dengue burden and socioeconomic factors, and then established an autoregressive integrated moving average (ARIMA) model to predict the epidemic trends of dengue in endemic regions. All estimates were proposed as numbers and age-standardized rates (ASR) per 100,000 population, with uncertainty intervals (UIs). The ASRs of dengue incidence were compared geographically and five regions were stratified by a sociodemographic index (SDI). RESULTS: A significant rise was observed on a global scale between 1990 and 2019, with the overall age-standardized rate (ASR) increasing from 557.15 (95% UI 243.32-1212.53) per 100,000 in 1990 to 740.4 (95% UI 478.2-1323.1) per 100,000 in 2019. In 2019, the Oceania region had the highest age-standardized incidence rates per 100,000 population (3173.48 (95% UI 762.33-6161.18)), followed by the South Asia region (1740.79 (95% UI 660.93-4287.12)), and then the Southeast Asia region (1153.57 (95% UI 1049.49-1281.59)). In Oceania, South Asia, and Southeast Asia, increase trends were found in the burden of dengue fever measured by ASRs of DALY which were consistent with ASRs of dengue incidence at the national level. Most of the countries with the heaviest burden of dengue fever occurred in areas with low and medium SDI regions. However, the burden in high-middle and high-SDI countries is relatively low, especially the Solomon Islands and Tonga in Oceania, the Maldives in South Asia and Indonesia in Southeast Asia. The age distribution results of the incidence rate and disease burden of dengue fever of major endemic regions showed that the higher risk and disease burden are mainly concentrated in people under 14 or over 70 years old. The prediction by ARIMA showed that the risk of dengue fever in South and Southeast Asia is on the rise, and further prevention and control is warranted. CONCLUSIONS: In view of the rapid population growth and urbanization in many dengue-endemic countries, our research results are of great significance for presenting the future trend in dengue fever. It is recommended to policy makers that specific attention needs to be paid to the negative impact of urbanization on dengue incidence and allocate more resources to the low-SDI areas and people under 14 or over 70 years old to reduce the burden of dengue fever.

6.
Korean J Parasitol ; 59(6): 615-623, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34974668

RESUMO

Human sparganosis is a food-borne parasitic disease caused by the plerocercoids of Spirometra species. Clinical diagnosis of sparganosis is crucial for effective treatment, thus it is important to identify sensitive and specific antigens of plerocercoids. The aim of the current study was to identify and characterize the immunogenic proteins of Spirometra erinaceieuropaei plerocercoids that were recognized by patient sera. Crude soluble extract of the plerocercoids were separated using 2-dimensional gel electrophoresis coupled with immunoblot and mass spectrometry analysis. Based on immunoblotting patterns and mass spectrometry results, 8 antigenic proteins were identified from the plerocercoid. Among the proteins, cysteine protease protein might be developed as an antigen for diagnosis of sparganosis.


Assuntos
Esparganose , Spirometra , Animais , Eletroforese em Gel Bidimensional , Humanos , Immunoblotting , Proteômica , Esparganose/diagnóstico
7.
Parasitol Res ; 119(4): 1259-1269, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32060726

RESUMO

To reveal the genetic diversity of Babesia microti and Theileria orientalis in Southwest China, we conducted a molecular survey of piroplasms in hard ticks in a China-Myanmar border county. Host infesting and questing ticks were collected from Tengchong County in 2013 and 2014. Piroplasm infection in ticks was detected by PCR, and then, phylogenetic analysis was conducted to study the genetic diversity of the pathogens identified in ticks. All in all, six piroplasm species comprising of B. microti; B. orientalis; a novel Babesia species designated Babesia sp. Tengchong, China; T. orientalis; T. luwenshuni; and an as yet undescribed piroplasmid species referred to as Piroplasmid sp. Tengchong, China, have been identified after screening goat- and cattle-attached ticks. In addition, B. bigemina has been identified by screening questing ticks. Phylogenetic analysis based on the 18S rRNA and partial ß-tubulin gene revealed two novel potentially zoonotic genotypes designated B. microti Tengchong-Type A and B. The T. orientalis genotypes identified in the present study represent the seven known genotypes 1-5, 7, and N3 as revealed by phylogenetic analysis of 18S rRNA and MPSP genes. Importantly, an additional genotype designated N4 has also been identified in this study, which brings the number of recognized T. orientalis genotypes to a total of twelve. Thus, besides the two novel species, Babesia sp. Tengchong, China, closely related to Babesia species isolated from yak and Piroplasmid sp. Tengchong, China, our study demonstrates that additional novel B. microti and T. orientalis genotypes exist in Southwest China.


Assuntos
Babesia microti/genética , Babesia/genética , Ixodidae/parasitologia , Theileria/genética , Animais , Babesia/classificação , Babesia/isolamento & purificação , Babesia microti/classificação , Babesia microti/isolamento & purificação , Bovinos , China , Genótipo , Mianmar , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 18S , Theileria/classificação , Theileria/isolamento & purificação
8.
BMC Microbiol ; 19(1): 273, 2019 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-31805864

RESUMO

BACKGROUND: Gut microbes can contribute to their hosts in food digestion, nutrient absorption, and inhibiting the growth of pathogens. However, only limited studies have focused on the gut microbiota of freshwater snails. Pomacea canaliculata is considered one of the worst invasive alien species in the world. Elucidating the diversity and composition of the microbiota in the gut of P. canaliculata snails may be helpful for better understanding the widespread invasion of this snail species. In this study, the buccal masses, stomachs, and intestines were isolated from seven P. canaliculata snails. The diversity and composition of the microbiota in the three gut sections were then investigated based on high-throughput Illumina sequencing targeting the V3-V4 regions of the 16S rRNA gene. RESULTS: The diversity of the microbiota was highest in the intestine but lowest in the buccal mass. A total of 29 phyla and 111 genera of bacteria were identified in all of the samples. In general, Ochrobactrum, a genus of putative cellulose-degrading bacteria, was the most abundant (overall relative abundance: 13.6%), followed by Sediminibacterium (9.7%), Desulfovibrio (7.8%), an unclassified genus in the family Aeromonadaceae (5.4%), and Cloacibacterium (5.4%). The composition of the microbiota was diverse among the different gut sections. Ochrobactrum (relative abundance: 23.15% ± 7.92%) and Sediminibacterium (16.95 ± 5.70%) were most abundant in the stomach, an unclassified genus in the family Porphyromonadaceae (14.28 ± 7.29%) and Leptotrichia (8.70 ± 4.46%) were highest in the buccal mass, and two genera in the families Aeromonadaceae (7.55 ± 4.53%) and Mollicutes (13.47 ± 13.03%) were highest in the intestine. CONCLUSIONS: The diversity and composition of the microbiome vary among different gut sections of P. canaliculata snails. Putative cellulose-degrading bacteria are enriched in the gut of P. canaliculata.


Assuntos
Bactérias/classificação , Microbioma Gastrointestinal , Trato Gastrointestinal/microbiologia , Caramujos/microbiologia , Animais , Feminino , Variação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Intestinos/microbiologia , RNA Ribossômico 16S/genética , Estômago/microbiologia
9.
Parasit Vectors ; 11(1): 469, 2018 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-30107820

RESUMO

BACKGROUND: Many tick species have great morphological similarity and are thus grouped into species complexes. Molecular methods are therefore useful in the classification and identification of ticks. However, little is known about the genetic diversity of hard ticks in China, especially at the subspecies level. Tengchong is one of the epidemic foci of tick-borne diseases in China, but the tick species inhabiting the local area are still unknown. METHODS: Eighteen villages in Tengchong County, China, were selected for sampling carried out from September to October 2014. Infesting hard ticks were removed from the body surface of domestic animals and questing ticks were collected from grazing fields. After morphological identification, molecular characteristics of each tick species were analyzed based on both 16S rRNA and cytochrome c oxidase subunit 1 (cox1) gene fragments. RESULTS: Six tick species were identified based on morphology: Rhipicephalus microplus, R. haemaphysaloides, Ixodes ovatus, Haemaphysalis longicornis, H. shimoga and H. kitaokai. Phylogenetic analysis using the cox1 gene revealed that R. microplus ticks from the present study belong to clade C. For tick samples of both R. haemaphysaloides and I. ovatus, three phylogenetic groups were recognized, and the intergroup genetic distances exceeded the usual tick species boundaries. Haemaphysalis longicornis ticks were clustered into two separate clades based on the cox1 gene. For ticks from both H. shimoga and H. kitaokai, two phylogenetic groups were recognized based on the phylogenetic analysis of the 16S rRNA gene, and the intergroup genetic distances also exceeded the known boundaries for closely related tick species. CONCLUSIONS: According to molecular analyses, new species or subspecies closely related to R. haemaphysaloides, I. ovatus, H. shimoga and H. kitaokai probably exist in the China-Myanmar border Tengchong County, or these ticks form species complexes with highly divergent mitochondrial lineages. Morphological comparisons are warranted to further confirm the taxonomic status of these tick species.


Assuntos
Animais Domésticos/parasitologia , Variação Genética , Ixodidae/genética , Infestações por Carrapato/veterinária , Animais , China/epidemiologia , Complexo IV da Cadeia de Transporte de Elétrons/genética , Ixodes/classificação , Ixodes/genética , Ixodidae/classificação , Mianmar/epidemiologia , Filogenia , RNA Ribossômico 16S/genética , Rhipicephalus/classificação , Rhipicephalus/genética , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia
10.
Front Microbiol ; 9: 1415, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30013530

RESUMO

Maternally inherited endosymbionts inhabit a variety of arthropods. Some of them can protect the arthropod host against a wide range of pathogens. However, very little is known about the association between endosymbionts and pathogen susceptibility in ticks. The present study investigated the effect of endosymbionts on larva-to-nymph transstadial transmission of Babesia microti by Rhipicephalus haemaphysaloides ticks. Engorged female ticks were injected with PBS, ciprofloxacin or kanamycin. The offspring larvae were used to infest B. microti-positive mice. Prevalence of B. microti among the nymphs in different treatment groups and its association with endosymbiont density in the larvae were analyzed. The results showed that the prevalence of B. microti in the kanamycin-treated group (63.9%, 95% confidence interval (CI): 52.8-75.0%) was higher than that in the PBS (23.6%, 95% CI: 13.8-33.4%) or ciprofloxacin-treated (25.0%, 95% CI: 15.0-35.0%) groups. This increased prevalence was associated with reduced density of Coxiella-like endosymbiont but was not related to the density of Rickettsia-like endosymbiont. No direct evidence has previously been reported about the impact of Coxiella-like endosymbiont on pathogen susceptibility in ticks. This study reveals that endosymbionts are potentially important defensive symbionts of R. haemaphysaloides which may influence the colonization or susceptibility of B. microti in the tick host.

11.
Parasit Vectors ; 11(1): 242, 2018 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-29653599

RESUMO

BACKGROUND: Endosymbiotic bacteria inhabit a variety of arthropods including ticks and may have multiple effects on the host's survival, reproduction or pathogen acquisition and transmission. Rhipicephalus haemaphysaloides is one of the most widely distributed tick species in China. The symbiotic bacteria composition and their impacts to R. haemaphysaloides ticks have not been studied. The present study investigated the composition of microbial community in R. haemaphysaloides ticks and then assessed the effects of endosymbionts on the host's fecundity by antibiotic treatment experiments. METHODS: The microbial population of female and male R. haemaphysaloides ticks was analyzed using Illumina Miseq sequencing of 16S rRNA gene. Thirty engorged female ticks were then randomly divided into five groups and injected with ampicillin, ciprofloxacin, kanamycin, tetracycline, or phosphate-buffered solution (PBS), respectively. Effects of antibiotic treatments on maternal oviposition, egg hatching and density of endosymbionts were evaluated. RESULTS: Illumina Miseq sequencing showed that Coxiella and Rickettsia were the predominant bacterial genera inhabiting R. haemaphysaloides ticks. Antibiotic treatment experiments found that kanamycin reduced the density of Coxiella-like endosymbiont (Coxiella-LE hereafter) in eggs, ciprofloxacin reduced the density of Rickettsia-like endosymbiont (Rickettsia-LE), and tetracycline had effect on both endosymbionts, while ampicillin affected neither. Meanwhile hatching rates of eggs were observed to decrease greatly in the kanamycin or tetracycline-treated group but maintained in the ampicillin or ciprofloxacin-treated group. Furthermore, the reduced hatching rates were found to be associated with density of Coxiella-LE in eggs. CONCLUSIONS: The findings indicate that Coxiella-LE is essential for the reproduction of R. haemaphysaloides ticks, and that kanamycin can be used to study the role of Coxiella-LE on ticks.


Assuntos
Antibacterianos/administração & dosagem , Consórcios Microbianos/genética , Rhipicephalus/efeitos dos fármacos , Rhipicephalus/fisiologia , Animais , Antibacterianos/efeitos adversos , Antibacterianos/uso terapêutico , Coxiella/genética , DNA Ribossômico/genética , Feminino , Fertilidade/efeitos dos fármacos , Masculino , Consórcios Microbianos/efeitos dos fármacos , Filogenia , RNA Ribossômico 16S/genética , Rhipicephalus/genética , Rhipicephalus/microbiologia , Rickettsia/genética , Análise de Sequência de DNA , Simbiose/efeitos dos fármacos
12.
Parasit Vectors ; 9: 231, 2016 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-27112141

RESUMO

BACKGROUND: Human babesiosis is considered an emerging threat in China. Dozens of human infections with Babesia microti have been reported recently, especially in southern China. However, the transmission vectors of this parasite in these areas are not well understood. Rhipicephalus haemaphysaloides, which is one of the dominant tick species in southern China, is a major vector of bovine babesiosis in China. However, whether this tick has the potential to transmit B. microti has not been tested. The present study experimentally investigated the transmission competence of B. microti through R. haemaphysaloides ticks. METHODS: Larvae and nymphs of R. haemaphysaloides ticks were fed on laboratory mice infected by B. microti. The infection was detected by PCR at 4 weeks post-molting. BALB/c and NOD/SCID mice were infested by nymphs molting from larvae that ingested the blood of infective mice, and blood samples were then analyzed by PCR. RESULTS: Experimental transstadial transmission of R. haemaphysaloides for B. microti was proved in both the larvae to nymph and the nymph to adult transstadial routes. The positive rate of B. microti was 43.8% in nymphs developed from larvae consumed infected mice and 96.7% in adults developed from nymphs exposed to positive mice. Among the mice infested by infective nymphs, B. microti was detected in 16.7% (2/12) of the BALB/c mice and in all of the NOD/SCID (6/6). However, the parasite was not observed to persist beyond more than one molt, and transovarial transmission did not occur. CONCLUSIONS: This is the first study to demonstrate that B. microti can be transmitted artificially by R. haemaphysaloides. This tick species might be a potential vector of human babesiosis in southern China, which represents a public health concern.


Assuntos
Babesia microti/fisiologia , Babesiose/transmissão , Rhipicephalus/parasitologia , Animais , Vetores Aracnídeos/parasitologia , Células 3T3 BALB , Babesiose/parasitologia , Feminino , Larva , Camundongos , Camundongos SCID , Ninfa , Organismos Livres de Patógenos Específicos
13.
Ying Yong Sheng Tai Xue Bao ; 27(3): 794-802, 2016 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-29726184

RESUMO

The impacts of three kinds of human disturbances, i.e., non-grazing, reseeding and free-grazing, on plant community characters, i.e., species composition, composition of functional groups, species diversity, and aboveground biomass, were studied in a typical steppe in Inner Mongolia, China. The results showed that different disturbances had significant impacts on the structure and diversity of plant functional groups. The number of plant species, aboveground biomass, community diversity, and richness indices were the highest in the non-grazing treatment, with the fi-gures of 22, 171.32 g·m-2, 1.46 and 5.7, respectively. The importance value (IV), percentage, aboveground biomass, diversity, richness, and evenness indices of shrub and sub-shrub, and perennial grasses were also the highest in the non-grazing treatment. In contrast, the IV, species percentage, aboveground biomass, diversity, and evenness indices of perennial forbs were the lowest in the non-grazing treatment. The aboveground biomass of mesophyte, C3 and C4 plants was the highe-st with the figures of 22.22, 143.35 and 27.97 g·m-2 respectively in the non-grazing treatment. The aboveground biomass of mesoxerophyte was highest (13.60 g·m-2), the species percentage of xerophyte was lowest (48.5%) and that of C4 plants was highest (28.8%) in the reseeding treatment. The species percentage of annual or biennial herbs was highest (12.3%), while that of mesophyte and C4 plants was lowest (17.0% and 20.9%) in the free-grazing treatment. The non-grazing treatment showed a beneficial effect for restoration of degraded grassland system.


Assuntos
Biodiversidade , Pradaria , Plantas/classificação , Biomassa , China , Recuperação e Remediação Ambiental , Poaceae
14.
J Tradit Chin Med ; 32(1): 12-8, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22594096

RESUMO

OBJECTIVE: To assess the effectiveness and safety of Traditional Chinese Medicine (TCM) treatment of non-acute bronchial asthma complicated by gastroesophageal reflux. METHODS: We searched databases from MEDLINE, Cochrane Library, CNKI, VIP, CBM, Wanfang Data, and TCM Database Systems. All randomized, controlled trials (RTCs) of TCM treatment of non-acute asthma complicated by gastroesophageal reflux were included. Data were independently collected by two reviewers. The standards for assessing quality described in the Cochrane Handbook for Systematic Reviews of Interventions were used to evaluate articles. Meta-analyses were conducted using Rev- Man 5.0.17 software. Heterogeneity was assessed, and a corresponding effects model was used to merge and analyze results. Indexes used to evaluate curative effects were: clinical efficacy, symptom scores, pulmonary function values, and adverse incidents. Effectiveness was indicated using risk ratio (RR) or mean difference (MD), and 95% confidence intervals (CIs) were calculated. RESULTS: Six RCTs were included, involving 304 patients with non-acute asthma complicated by gastroesophageal reflux. The treatment groups received Chinese drugs alone or TCM combined with standard Western medical treatment, and the control groups received standard Western medical treatment alone. Standard Western medical treatment included anti-inflammatory drugs and bronchodilators for asthma, and drugs to promote gastric peristalsis and inhibit gastric acid production for gastroesophageal reflux. Methodological quality was low in all six RCTs. Two RCTs showed that clinical efficacy was higher in the treatment group than in the control group (RR: 1.43, 95%CI: 1.10 to 1.87 vs RR: 1.51, 95% CI: 1.09 to 2.08). One RCT showed that the asthma score was lowered more effectively in the treatment group than in the control group (MD:-1.10, 95% CI:-2.04 to-0.16). Two RCTs showed that the gastroesophageal reflux score was reduced more effectively in the treatment group than in the control group (RR:-3.70, 95% CI:-4.30 to 3.10 vs RR:-5.30, 95% CI:-6.32 to -4.28). One RCT showed that some pulmonary function values were improved more effectively in the treatment group than in the control group (P < 0.05). No differences were seen in the various indexes between groups in the other RCTs. No adverse reactions, dropout rates, or follow-up rates were reported in any of the RCTs. CONCLUSIONS: The clinical symptoms of non-acute asthma complicated by gastroesophageal reflux can be improved by some Chinese drugs. Curative effects can be increased by combining the use of TCM with Western medicine. Because of the small quantity and low quality of research reported to date, it is necessary to conduct further RCTs to confirm these results. The results of this systematic review indicate that the quality of future clinical trials should be improved by including larger patient numbers, correctly randomizing patients into study groups, using blinding methods to measure and assess outcomes, and using accepted indexes to evaluate curative effects.


Assuntos
Asma/tratamento farmacológico , Medicamentos de Ervas Chinesas/uso terapêutico , Refluxo Gastroesofágico/tratamento farmacológico , Asma/complicações , Feminino , Refluxo Gastroesofágico/complicações , Humanos , Masculino , Ensaios Clínicos Controlados Aleatórios como Assunto
15.
Sleep Med ; 13(4): 342-5, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22172960

RESUMO

OBJECTIVE: To assess the prevalence and severity of restless legs syndrome (RLS) in a town in China and to explore potential factors correlated with the severity of the disease. METHODS: Face-to-face home interviews were conducted among a random sample of 2101 residents in one town in China, all aged 16 years and above. An individual questionnaire was administered to all participants to obtain a diagnosis of RLS and other information. An additional questionnaire was then handed out to each patient diagnosed with RLS to collect information on RLS severity and potential factors correlating with RLS severity. RESULTS: The prevalence of RLS in the studied population was 7.2%. The prevalence in women was significantly higher than in men and increased with age. Diabetes mellitus, anemia, arthritis, and varicose veins were also associated with RLS. Among the 152 patients, 21.7% were classified as having severe RLS. Multiple correlation analysis reveals that RLS severity was positively correlated with longer disease duration, number of cigarettes smoked per day, and level of work-related physical activity, but negatively correlated with level of leisure time physical activity. CONCLUSIONS: RLS is common in the studied population. Lifestyle factors may be associated with RLS severity.


Assuntos
Povo Asiático/estatística & dados numéricos , Síndrome das Pernas Inquietas/etnologia , Síndrome das Pernas Inquietas/fisiopatologia , Índice de Gravidade de Doença , Adolescente , Adulto , China/epidemiologia , Comorbidade , Estudos Transversais , Feminino , Inquéritos Epidemiológicos , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Prevalência , Características de Residência , Distribuição por Sexo , Fumar/etnologia , Inquéritos e Questionários , Adulto Jovem
16.
Zhong Xi Yi Jie He Xue Bao ; 9(3): 246-51, 2011 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-21419076

RESUMO

Following the development of clinical trials, the methodology of clinical trials has developed a great deal, including randomization method and blinding method, etc. The method of randomization includes simple randomization, stratification randomization, etc. Dynamic randomization is also considered as a method of randomization. Two dynamic randomization methods are introduced in this paper, including a method considering the balance of numbers in each group and a method considering prognostic factors. This paper also demonstrates the procedure of dynamic randomization of the above two methods by simulations and actual examples.


Assuntos
Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Projetos de Pesquisa , Humanos , Distribuição Aleatória
17.
Parasit Vectors ; 1(1): 40, 2008 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-18937874

RESUMO

Blastocystis is a prevalent enteric protozoan that infects a variety of vertebrates. Infection with Blastocystis in humans has been associated with abdominal pain, diarrhea, constipation, fatigue, skin rash, and other symptoms. Researchers using different methods and examining different patient groups have reported asymptomatic infection, acute symptomatic infection, and chronic symptomatic infection. The variation in accounts has lead to disagreements concerning the role of Blastocystis in human disease, and the importance of treating it. A better understanding of the number of species of Blastocystis that can infect humans, along with realization of the limitations of the existing clinical laboratory diagnostic techniques may account for much of the disagreement. The possibility that disagreement was caused by the emergence of particular pathogenic variants of Blastocystis is discussed, along with the potential role of Blastocystis infection in irritable bowel syndrome (IBS). Findings are discussed concerning the role of protease-activated receptor-2 in enteric disease which may account for the presence of abdominal pain and diffuse symptoms in Blastocystis infection, even in the absence of fever and endoscopic findings. The availability of better diagnostic techniques and treatments for Blastocystis infection may be of value in understanding chronic gastrointestinal illness of unknown etiology.

18.
Am J Trop Med Hyg ; 78(5): 760-9, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18458311

RESUMO

Intestinal multiparasitism, the accuracy of different diagnostic techniques, and the influence of sampling effort were studied among 215 individuals in a Bulang village, Yunnan province, People's Republic of China. Behavioral, demographic, and socioeconomic data were obtained by questionnaire. Multiple stool specimens were examined by the Kato-Katz, Koga agar plate, Baermann, and ether-concentration methods. Eight helminth and 7 protozoa species were diagnosed. The prevalence of each of the 3 main soil-transmitted helminths (Ascaris lumbricoides, hookworm, and Trichuris trichiura) exceeded 85%. Blastocystis hominis was the most prevalent intestinal protozoan (20.0%). Over 80% of the individuals harbored 3 or more intestinal parasites concurrently. The infection intensities were predominantly light for hookworm and T. trichiura but moderate for A. lumbricoides. Examination of 3 instead of 1 stool specimen increased the sensitivity of helminth diagnosis, most notably for hookworm. Intestinal multiparasitism is rampant in this rural part of Yunnan province and calls for control measures.


Assuntos
Doenças Parasitárias/epidemiologia , População Rural/estatística & dados numéricos , Distribuição por Idade , China/epidemiologia , Fezes/parasitologia , Inquéritos Epidemiológicos , Humanos , Doenças Parasitárias/diagnóstico , Cooperação do Paciente , Prevalência , Inquéritos e Questionários
19.
PLoS Negl Trop Dis ; 1(1): e75, 2007 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-17989788

RESUMO

BACKGROUND: Strongyloides stercoralis is a neglected soil-transmitted helminth species, and there is a lack of parasitologic and epidemiologic data pertaining to this parasite in China and elsewhere. We studied the local occurrence of S. stercoralis in a village in Yunnan province, China, and comparatively assessed the performance of different diagnostic methods. METHODOLOGY/PRINCIPAL FINDINGS: Multiple stool samples from a random population sample were subjected to the Kato-Katz method, an ether-concentration technique, the Koga agar plate method, and the Baermann technique. Among 180 participants who submitted at least 2 stool samples, we found a S. stercoralis prevalence of 11.7%. Males had a significantly higher prevalence than females (18.3% versus 6.1%, p = 0.011), and infections were absent in individuals <15 years of age. Infections were only detected by the Baermann (highest sensitivity) and the Koga agar plate method, but neither with the Kato-Katz nor an ether-concentration technique. The examination of 3 stool samples rather than a single one resulted in the detection of 62% and 100% more infections when employing the Koga agar plate and the Baermann technique, respectively. The use of a mathematical model revealed a 'true' S. stercoralis prevalence in the current setting of up to 16.3%. CONCLUSIONS/SIGNIFICANCE: We conclude that S. stercoralis is endemic in the southern part of Yunnan province and that differential diagnosis and integrated control of intestinal helminth infections needs more pointed emphasis in rural China.


Assuntos
Strongyloides stercoralis/patogenicidade , Estrongiloidíase/epidemiologia , Adolescente , Adulto , Ágar , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , China/epidemiologia , Diagnóstico Diferencial , Etnicidade , Características da Família , Fezes/parasitologia , Feminino , Geografia , Humanos , Intestinos/parasitologia , Masculino , Pessoa de Meia-Idade , Prevalência , População Rural/estatística & dados numéricos , Saneamento/normas , Strongyloides stercoralis/crescimento & desenvolvimento , Strongyloides stercoralis/isolamento & purificação , Estrongiloidíase/diagnóstico , Inquéritos e Questionários
20.
Parasitol Res ; 102(1): 83-90, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17912552

RESUMO

The prevalence and geographical distribution of the intestinal protozoa Blastocystis in humans across China is unknown, and the relative importance of different subtypes has yet to be investigated. We assessed the community prevalence and relative frequencies of different Blastocystis subtypes in four epidemiological settings in China, i.e., Shanghai municipality, Yongjia county (Zhejiang province), Eryuan county, and Menghai county (both Yunnan province). Blastocystis infection was detected with the culture method, and the subtype was identified with polymerase chain reaction using a set of subtype-specific primers. The prevalence at the four study settings was 1.9, 5.9, 18.4, and 32.6%, respectively. People aged greater than or equal to 60 years had a higher prevalence in the former two settings, Shanghai and Yongjia, whereas the highest infection rate was found among individuals aged 10-17 years in the latter two settings, Eryuan and Menghai. A higher prevalence was found in men in the former two settings but in women in the latter two settings. Five different Blastocystis subtypes were identified from the 192 isolates. Subtype 3 was the predominant type, followed by subtype 1. In conclusion, the epidemiology of Blastocystis varies across China.


Assuntos
Infecções por Blastocystis/epidemiologia , Infecções por Blastocystis/parasitologia , Blastocystis/classificação , Blastocystis/isolamento & purificação , Adolescente , Adulto , Distribuição por Idade , Animais , Criança , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RNA de Protozoário/genética , RNA Ribossômico/genética , Adulto Jovem
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