Endemic Regions Of China Research Articles

Evidence of being cured for nasopharyngeal carcinoma: results of a multicenter patient-based study in China

The survival rates of patients with nasopharyngeal carcinoma (NPC) have improved significantly, but there is no consensus on whether they can be considered cured. We aimed to determine whether a statistical cure could be achieved for patients with NPC in the contemporary therapeutic landscape. This retrospective multicenter study enrolled 6315 patients with nonmetastatic NPC from nonendemic and endemic regions of China from 2007 to 2020. We applied mixture and nonmixture cure models to estimate the cure probabilities and cure times by incorporating background mortality for the general population, matching by gender, age, and diagnosed year. With death as the uncured event, the probability of patients with NPC achieving a life expectancy at par with the general population was 78.1%. Considering progression as the uncured event, the likelihood of patients attaining a life expectancy without progression equivalent to that of the general population was 72.4%. For individuals, the probabilities of achieving cure were conditional and time-dependent, requiring approximately 7.1 and 4.7 years with 95% certainty, respectively. The corresponding cure times for uncured patients were 8.9 and 6.8 years, respectively. The cure probability was correlated with age, Eastern Cooperative Oncology Group score, TNM staging, Epstein-Barr virus DNA copies, and lactate dehydrogenase. The correlation was excellent between 5-year overall survival/progression-free survival and cure fractions. Statistical cure is potentially achievable among patients with NPC undergoing contemporary treatment modalities. The results hold significant potential implications for both clinical practice and patient perspectives. National High Level Hospital Clinical Research Funding; Beijing Xisike Clinical Oncology Research Foundation; Beijing hope run fund.

Knowledge, attitudes, and practices (KAPs) regarding tick-borne rickettsial disease among medical staff in endemic areas of China.

Tick-borne rickettsial disease (TBRD) is a perilous acute infection that often eludes diagnosis in its early stages. The triad of knowledge, attitudes, and practices (KAPs) among medical professionals is key to reducing missed diagnosis rates. Therefore, a meticulous evaluation of KAPs is imperative. This study aimed to delve into the understanding of TBRD and explore the beliefs and practices related to personal prevention methods among individuals in Lu'an, a hotspot for TBRD. During the summer months of 2023, convenience sampling was employed by circulating a confidential questionnaire to 1,206 participants in the endemic regions of China. This questionnaire painted a comprehensive picture of the participants' sociodemographic profiles and their KAPs levels vis-à-vis TBRD. The findings revealed that participants scored a mere 55.78% in knowledge, while their attitudes and practices garnered impressive scores of 90.09% and 90.83%, respectively. Upon further analysis using multiple linear regression, several intriguing patterns emerged. Male participants, employed in the Infectious Disease Department, held vice-senior or higher titles, or had prior medical training demonstrated superior knowledge scores. On the other hand, medical personnel who were younger than 30, possessed graduate degrees or higher qualifications, and had training excelled in attitudes and practices. Notably, when employing the Boston Consulting Group (BCG) matrix, a significant distribution of medical personnel was observed across the four quadrants. Specifically, 37.43%, 13.19%, 19.61%, and 29.77% fell into the first, second, third, and fourth quadrants. This survey underscores the commendable attitudes and practices of medical staff towards TBRD in endemic regions of China. However, their knowledge level remains wanting and demands urgent improvement.

Prevalence of African Swine Fever in China, 2018-2019.

African swine fever (ASF) has spread widely across China since 2018. It represents a significant threat to the pig production industry, as no treatment or vaccine is available for this disease. In this study, the geographical distribution and epidemiological features of ASF from all endemic regions of China were analyzed. We focused on the epidemiological data from 149 ASF cases among domestic pigs and wild boars, confirmed during 2018-2019. We found that, in the 1-year period from August 2018 to July 2019, ASF was reported in most geographical regions of the country, which comprises 31 provinces. The outbreaks were mainly located along the important economic zones and tended to increase southward in general. The southwest region was the most severely affected, with 22% of cases, followed by the Northeast, with 20% of cases. There was no significant difference among other regions. Additionally, the overall mean rate of case-incidence/fatality was 12.5% and 64%, respectively, in this period and varied significantly different months, with a general trend towards a decrease over time. The highest incidence rate (30.4%) occurred in April-May 2019, and the highest fatality rate (81.21%) in October-November 2018, demonstrating the marked seasonality in ASF transmission. Furthermore, anthropogenic effects were a major significant risk factor for the spread of the disease. In summary, this initial epidemiological analysis of ASF provides a global perspective on ASF and facilitates detection of trends and patterns, which will be useful for updating preventive actions at a national level and evaluating their impact on public health.

Investigation and research of Clonorchis sinensis metacercariae and Metorchis orientalis metacercariae infection in freshwater fishes in China from 2015 to 2017

BackgroundClonorchiasis has been known for over 2300 years in China and it is considered as one of the most notorious food-borne parasitic diseases. In 2004, a total number of 15 million people were infected with Clonorchis sinensis around the world, in which more than 85% people lived in China. This was the first epidemical study about Clonorchis sinensis metacercariae and Metorchis orientalis metacercariae infection in freshwater fishes in seven endemic regions of China. MethodsA total number of 2909 samples were collected from year 2015–2017. The regions of epidemic area of C. sinensis and Metorchis orientalis included Jilin, Heilongjiang, Shanghai, Zhejiang, Anhui, Guangdong and Guangxi provinces of China. 16 fish species were examined. Encysted metacercariae of C. sinensis and Metorchis orientalis were examined with digestion technique. The chi-square test, the Fisher's exact test and the logistic regression were applied in this study. ResultsThe infection rate of C. sinensis metacercariae was 3.10% (90/2904) and that of Metorchis orientalis metacercariae was 1.20% (34/2831). The infected freshwater fishes were sold in different locations including fish pond, farm produce market, supermarket and restaurant. The infection rates of C. sinensis metacercariae and Metorchis orientalis metacercariae in Pseudorasbora parva were the highest up to 25.00% (17/68) and 14.93% (10/67), respectively. ConclusionsFish species was the major influence factor to the infection rates of C. sinensis metacercariae and Metorchis orientalis metacercariae.

Hair multi-bioelement profile of Kashin-Beck disease in the endemic regions of China

BackgroundKashin-Beck disease (KBD) is a serious chronic osteochondral disease that is endemic in humans. Selenium (Se) has been considered in hypotheses of the aetiology of KBD, but few studies have explored the relationship between other elements and KBD. ObjectiveThis study explored the relationship between 39 elements and KBD. Methods: In this retrospective study, 150 boys aged 6 to 14 years were randomly selected from a total population of 1,214 children. Subjects from endemic areas were divided into five groups: (KBD -Bin, N = 30; KBD + Se-Yongshou, N = 30; Control -Bin, N = 30; Control + Se -Yongshou, N = 30; and Control External -Chang’an, N = 30). Samples of occipital hair were collected from each subject, and thirty-nine elements, including 15 toxic elements, 19 nutrient elements, and 5 other elements were assayed by inductively coupled plasma mass spectrometry (ICP-MS). Correlation analysis of the elements in each group was performed by ggcorrplot (visualization of a correlation matrix using 'ggplot2') and PerformanceAnalytics packages in the program R Project. ResultsAmong the 15 toxic elements, the levels of aluminum (Al) and bismuth (Bi) in the KBD -Bin were significantly higher than in the other groups, and the levels of silver (Ag), beryllium (Be), platinum (Pt), antimony (Sb), tin (Sn) and lead (Pb) in the KBD -Bin were significantly lower than in the other groups. Among the 19 nutrient elements, the levels of selenium (Se), iodine (I), sulfur (S), and boron (B) in the KBD -Bin were significantly lower than in the other groups. The levels of calcium (Ca), iron (Fe), manganese (Mn), chromium (Cr), strontium (Sr) and phosphorus (P) in the KBD -Bin were significantly higher than in the other groups. Correlations between various elements were remarkably different among the groups. There were positive correlations between As and Pb, Cd and Sb, Pb and Sb, Sb and U in the Control External -Chang’an, between Al and Ni, Cd and Pb, Tl and Ni, Ti and U in the Se-S KBD, and between B and I, B and Mo, Mn and V in the Control External -Chang’an. ConclusionsThese findings indicate that the interactions between elements do not represent a simple reciprocal relationship in the occurrence of KBD. In fact, KBD was associated with an imbalance in multiple elements that play a dynamic and interactive role in the development of the disease.

Community-based comprehensive measures to prevent severe fever with thrombocytopenia syndrome, China

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging disease caused by the SFTS virus (SFTSV) of the family Bunyaviridae. Since the virus was first isolated in 2009, it has become widespread in China, with an increasing number of cases year on year. Although the disease has been researched extensively in past years, there are still no effective measures to suppress the epidemic situation. This article reports a pilot study of comprehensive measures, including health education and risk communication, weed removal, livestock management, and tick control, to prevent this emerging disease in an endemic region of China. The density of ticks decreased dramatically month by month after acaricides were sprayed in the areas surrounding recreational and agricultural settings. The number of SFTS cases and villages involved declined in the years after the integrated measures were applied. Comprehensive measures, especially community-based tick control, may be a promising means of preventing SFTS in endemic regions.

Survival and Toxicities of IMRT Based on the RTOG Protocols in Patients with Nasopharyngeal Carcinoma from the Endemic Regions of China.

Background: This study evaluated the survival outcomes and toxicities of intensity-modulated radiation therapy (IMRT) based on the RTOG 0225/0615 RT protocols in patients with nasopharyngeal carcinoma (NPC) from a region of China where this tumor type is endemic.Methods: A total of 455 patients with non-metastatic, histologically-confirmed NPC were retrospectively reviewed. All patients were treated by IMRT using the RTOG 0225/0615 RT protocols; 91.1% (288/316) of patients with stage III-IVb NPC received concurrent chemotherapy +/- induction chemotherapy or adjuvant chemotherapy.Results: Estimated four-year overall survival (OS), failure free survival (FFS), local relapse free survival (LRFS), regional relapse free survival (RRFS) and distant metastasis free survival (DMFS) were 83.8%, 80.5%, 94.3%, 96.7% and 85.8%, respectively. T and N category were significant prognostic factors for OS, FFS, RRFS and DMFS; and T category, for LRFS. In-field failure was the major loco-regional failure pattern. During RT, 206 (45.3%) patients experienced acute grade 3-4 toxicities. The most common acute toxicity was mucositis; 124 (27.2%) patients experienced grade 3-4 mucositis; 46 (10.1%) experienced serious late toxicities. The most common late toxicity was MRI-detected radiation-induced temporal lobe necrosis (6.8%).Conclusions: The RTOG IMRT protocols are feasible for patients with NPC from the endemic regions of China.

Urban-Rural Disparity in Helicobacter Pylori Infection–Related Upper Gastrointestinal Cancer in China and the Decreasing Trend in Parallel with Socioeconomic Development and Urbanization in an Endemic Area

BackgroundGlobally China has the largest urban-rural disparity in socioeconomic development, and the urban-rural difference in upper gastrointestinal cancer (UGIC) is similar to the difference between developed and developing countries. ObjectivesTo describe urban-rural disparity in UGIC and to emphasize prevention by socioeconomic development and urbanization in China. MethodsAge-standardized incidence rates (ASRs) of cancers in 2012 were compared between urban Shijiazhuang city and rural Shexian County, and trends from 2000-2015 in Shexian County were analyzed. FindingsCompared with urban Shijiazhuang city, the ASR of gastroesophageal cancers in rural Shexian County was 5.3 times higher in men (234.1 vs 44.2/100,000, P < .01) and 9.1 times higher in women (107.7 vs 11.8/100,000, P < .01). This rural-urban disparity in UGIC is associated with differences in socioeconomic development in annual gross domestic product (GDP) per capita of US$2700 vs US$6965, in urbanization rate of 48% vs 100%, and in adult Helicobacter pylori infection prevalence of 75% vs 50%. From 2000-2015, the GDP per capita in Shexian County increased from US$860 to US$3000, urbanization rate increased from 22.4% to 54.8%, and prevalence of H pylori infection among 3- to 10-year-old children decreased from 60% to 46.1% (P < .01). Meanwhile, the biennial ASR of esophagogastric cancer decreased 42% in men, from 313.5 to 182.1 per 100,000 (P < .01), and 57% in women, from 188.6 to 80.4 per 100,000 (P = .00). However, lung, colorectal, and gallbladder cancers and leukemia in both sexes and breast, ovary, thyroid, and kidney cancer in women increased significantly. Despite this offset, ASR of all cancers combined decreased 25% in men (from 378.2 to 283.0/100,000, P = .00) and 19% in women (from 238.5 to 193.6/100,000, P = .00). ConclusionsUrban-rural disparity in UGIC is related to inequity in socioeconomic development. Economic growth and urbanization is effective for prevention in endemic regions in China and should be a policy priority.

Novel monoclonal antibodies against Plasmodium falciparum histidine-rich protein 2: development and application in rapid diagnostic tests of malaria in hyperendemic regions of China and Myanmar.

BackgroundMalaria presents a considerable threat to public health. Histidine-rich protein 2 (HRP 2) is the major protein released into human blood upon infection by Plasmodium falciparum. In this study, we aimed to evaluate the immunogenicity of HRP 2 exon II and the efficacy of novel monoclonal antibodies (mAbs) against HRP 2 for Point-of-Care Test (POCT).MethodsThe recombinant protein was expressed in soluble form in E. coli and used to immunize mice for mAb production. Two IgG1 mAbs (1A5 and 1C10) with high affinity, specificity and sensitivity for both native and recombinant HRP 2 were selected after fusion of mouse spleen with myeloma cells. The affinity constant of 1A5 and 1C10 were 7.15 and 4.91 × 10-7 L/mol, respectively. Subsequently, an immunochromatograhic assay was used for screening of clinical samples in endemic regions of China and Myanmar.ResultsThe immunochromatographic test retrospectively showed an overall sensitivity of 99.07%, and specificity of 100%. Sensitivity at parasite densities < 200, 200–2000, and > 2000 parasites/μL was 87.5, 98.7, and 100%, respectively.ConclusionsThese results suggest that HRP 2 exon II contains immunogenic sites similar to those of the native antigen and can be used for the development of mAbs suitable for malaria diagnosis in endemic communities.

Reduced Aflatoxin Exposure Presages Decline in Liver Cancer Mortality in an Endemic Region of China

Primary liver cancer (PLC) is the third leading cause of cancer mortality globally. In endemic areas of sub-Saharan Africa and Asia, PLC largely arises from chronic infection with hepatitis B virus (HBV) and ingestion of aflatoxins. Although synergistic interactions between these two risk factors have been observed in cohort studies in China, here we determined the impact of agricultural reforms in the 1980s leading to diminished maize consumption and implementation of subsidized universal vaccination against HBV in the 2000s on PLC primary prevention. A population-based cancer registry was used to track PLC mortality in Qidong, China and was compared with the timeline of HBV immunization. Randomly selected serum samples from archived cohort collections from the 1980s to present were analyzed for aflatoxin biomarkers. More than 50% reductions in PLC mortality rates occurred across birth cohorts from the 1960s to the 1980s for Qidongese less than 35 years of age although all were born before universal vaccination of newborns. Median levels of the aflatoxin biomarker decreased from 19.3 pg/mg albumin in 1989 to undetectable (<0.5 pg/mg) by 2009. A population attributable benefit of 65% for reduced PLC mortality was estimated from a government-facilitated switch of dietary staple from maize to rice; 83% of this benefit was in those infected with HBV. Food policy reforms in China resulted in a dramatic decrease in aflatoxin exposure, which, independent of HBV vaccination, reduced liver cancer risk. The extensive HBV vaccine coverage now in place augurs even greater risk reductions in the future.

Endemic characteristics of infantile visceral leishmaniasis in the People’s Republic of China

BackgroundVisceral leishmaniasis (VL) was once a severe parasitic disease in China. Thanks to the great efforts of integrated control, VL was eliminated in most epidemic areas, except for certain western provinces (autonomous region) at the end of 1950s. From then on, VL gained less attention and has seemed to spread, especially in the last 15 years. Infants are the most important population threatened by VL. However, there have been few studies on the endemic characteristics of infantile VL in China.MethodsInfantile VL cases were collected from the online National Infectious Diseases Reporting System (NIDRS). Statistical description and inference was used to reveal the endemic characteristics in gender, age group, time and regionalism. Spatial analysis was carried out to explore the high risk area for infantile VL in China.ResultsA total of 1093 infantile VL cases were reported from 2006 to 2012. There was no statistically significant difference in gender over time. The minimum, maximum and mean age of these cases was 1.1, 35.9 and 13.8 months, respectively. Among them 86.92% were under 2 years of age, and there was a statistically significant difference among age groups over time. An incidence peak appeared in 2008-2009, most cases were distributed in the months September to December, and there was a tail-raising effect in the coming two months of the next year. More than 98% of cases were reported in Xinjiang Uygur Autonomous Region, Gansu Province and Sichuan Province, accounting for 61.02%, 32.75% and 4.57%, respectively. A total of 56 counties reported infantile VL cases, with the cumulative incidence ranging from 0.02 to 24.57%. There were two main zones of high endemicity for infantile VL in China. The monthly incidence clearly coincides with the number of towns where infantile VL cases were reported. Three fatalities were reported during the study period, the case fatality rate was 2.75‰.ConclusionsThe endemic situation of infantile VL is serious, and there are several active foci of infantile VL prevalence in China. VL has emerged as a severe threat to infants of endemic regions in China.

Progress report of a randomized trial comparing long‐term survival and late toxicity of concurrent chemoradiotherapy with adjuvant chemotherapy versus radiotherapy alone in patients with stage III to IVB nasopharyngeal carcinoma from endemic regions of China

The objective of this study was to evaluate the long-term survival and late toxicities of concurrent-adjuvant chemotherapy in patients with stage III through IVB nasopharyngeal carcinoma (NPC) from endemic regions of China. Patients with stage III to IVB NPC were assigned randomly to receive radiotherapy (RT) alone (the RT group) or RT plus concurrent adjuvant chemotherapy (the CRT group). CRT patients received concurrent cisplatin (40 mg/m2) weekly during RT followed by cisplatin (80 mg/m2) and fluorouracil (800 mg/m(2) daily for 5 days) every 4 weeks for 3 cycles. The primary endpoint was overall survival. In total, 316 patients underwent randomization, with 158 to each group. At a median follow-up of 70 months, the 5-year overall survival rate was 72% for the CRT group and 62% for the RT group (hazard ratio, 0.69; 95% confidence interval, 0.48-0.99; P = .043). Failure-free survival was significantly higher in the CRT group (P = .020). Most late toxicities were similar (33% vs. 26%; P = .089), except for cranial neuropathy (P = .042), peripheral neuropathy (P = .041), and ear damage (P = .048), which were significantly increased in the CRT group. The addition of concurrent adjuvant chemotherapy to RT provides survival benefits to patients with stage III through IVB NPC in endemic regions of China, and it does not increase most late toxicities apart from cranial neuropathy, peripheral neuropathy, and ear damage.

Improving Access to Anti-Schistosome Treatment and Care in Nonendemic Areas of China: Lessons from One Case of Advanced Schistosomiasis Japonica

Schistosomiasis, caused by trematode blood flukes of the genus Schistosoma, is the second most prevalent disease after malaria in the tropical and subtropical world. Among five schistosome species, Schistosoma japonicum is the most serious, mainly because of its high egg output [1]. This parasite is mainly endemic in mainland China, the Philippines, and Indonesia. Advanced schistosomiasis, due to either an infection without chemotherapy or repeated infections over time, is the most serious form of schistosomiasis and is usually characterized by periportal liver fibrosis, spleen enlargement and congestion, portal hypertension, and other serious consequences [2]. The suffering for an advanced patient caused by schistosomes could last for a lifetime, as the associated pathological changes on the host, if not properly treated, could develop toward a more serious condition. In addition, S. japonicum in humans has been estimated to be able to live for an average of 4.5 years [3]. Prolonged survival of the parasite to as long as about 47 years has been seen in an American who emigrated from the Philippines and continued to show active eggs in rectal biopsies [4]. These eggs can continue to produce damages to organs where they are deposited. Therefore, the treatment of the disease usually includes both anti-schistosome treatment and symptomatic therapy. The former is based on fecal examinations and serological tests, which are usually negative in most cases [5], or endoscopic examination. The etiological treatment is comparatively easier when without any serious complication, and therefore, much more attention and financial aids are going to the latter. In the Zhejiang province of China for example, in 2003 there remained 1,187 advanced cases who still needed medical assistance, although the disease there had been interrupted a decade ago [6]. Such a looming problem has been suggested to exist for perhaps as long as another half century in China [7]. Fortunately, with the economic development and well-improved standards of living over the last decades in China, in 2004 the government of China redefined schistosomiasis control, together with the control of HIV/AIDS and tuberculosis, as one of its highest priorities in communicable disease control [8]. As one main part of the integrated control measures, the project for treatment of advanced schistosomiasis has been initiated across the endemic regions of China. Box 1 lists a series of regulations on that aspect made by the government. The main point of this is that a screening system for advanced schistosomiasis among local residents will be set up in each endemic county and, if a farmer is diagnosed with advanced schistosomiasis (see Box 2 for the diagnosis criteria), the involved medical expense will be mostly covered by different levels of government. Figure 1 shows the numbers of advanced cases and newly found cases in each province and, as the consequence of the project, the increasingly rising coverage rate of advanced cases [9]. The direct or long-term estimated benefit from this project, as estimated by the work [10], would be quite considerable. Here we presented a case observed in a nonendemic area within the Anhui Province of China to point out the demerit of the ongoing project and raise some aspects yet to improve. This follow-up investigation was approved by an ethics committee in both the Anhui Institute of Parasitic Diseases and Soochow University. A consent form was obtained from the patient, and she gave consent to have her case details published. Open in a separate window Figure 1 Numbers of advanced schistosomiasis japonica in China. (A) In each province by 2008; (B) in each province by 2003 and new cases found from 2004 to 2008; and (C) the coverage rates of the aid-project in the cases at the levels of nation or province (Anhui) over 2004 to 2008.

Changes in serum thioredoxin among individuals chronically exposed to arsenic in drinking water

It is well known that oxidative damage plays a key role in the development of chronic arsenicosis. There is a complex set of mechanisms of redox cycling in vivo to protect cells from the damage. In this study, we examined the differences in the levels of serum thioredoxin1 (TRX1) among individuals exposed to different levels of arsenic in drinking water and detected early biomarkers of arsenic poisoning before the appearance of skin lesions. A total of 157 subjects from endemic regions of China were selected and divided into arsenicosis group with skin lesions (total intake of arsenic: 8.68–45.71mg-year) and non-arsenicosis group without skin lesions, which further divided into low (0.00–1.06mg-year), medium (1.37–3.55mg-year), and high (4.26–48.13mg-year) arsenic exposure groups. Concentrations of serum TRX1 were analyzed by an ELISA method. Levels of water arsenic and urinary speciated arsenics, including inorganic arsenic (iAs), monomethylated arsenic (MMA), and dimethylated arsenic (DMA), were determined by hydride generation atomic absorption spectrometry. Our results showed that the levels of serum TRX1 in arsenicosis patients were significantly higher than that of the subjects who were chronically exposed to arsenic, but without skin lesions. A positive correlation was seen between the levels of serum TRX1 and the total water arsenic intake or the levels of urinary arsenic species. The results of this study indicate that arsenic exposure could significantly change the levels of human serum TRX1, which can be detected before arsenic-specific dermatological symptoms occur. This study provides further evidence on revealing the mechanism of arsenic toxicity.

Genetic variation amongClonorchis sinensisisolates from different geographic regions in China revealed by sequence analyses of four mitochondrial genes

The present study examined sequence variation in four mitochondrial (mt) genes, namely cytochrome c oxidase subunits 1 (cox1) and 2 (cox2), and NADH dehydrogenase subunits 1 and 2 (nad1 and nad2) among Clonorchis sinensis isolates from different endemic regions in China, and their phylogenetic relationships with other zoonotic trematodes were reconstructed. A portion of the cox1 and cox2 genes (pcox1 and pcox2), and nad1 and nad2 genes (pnad1 and pnad2) were amplified separately from individual liver flukes by polymerase chain reaction (PCR) and the amplicons were subjected to sequencing from both directions. The intra-specific sequence variations within C. sinensis were 0-1.6% for pcox1, 0-1.4% for pcox2, 0-0.9% for pnad1 and 0-1.0% for pnad2. Phylogenetic analyses based on the combined sequences of pcox1, pcox2, pnad1 and pnad2 revealed that all the C. sinensis isolates grouped together and were closely related to Opisthorchis felineus. These findings revealed the existence of intra-specific variation in mitochondrial DNA (mtDNA) sequences among C. sinensis isolates from different geographic regions, and demonstrated that mtDNA sequences provide reliable genetic markers for phylogenetic studies of zoonotic trematodes.

Phylogeography of Ascaris lumbricoides and A. suum from China

In order to obtain further understanding of genetic structure and evolutionary relationship of Ascaris from humans and pigs, phylogeography study on 12 populations from six endemic regions in China was conducted using mitochondrial DNA markers (cytochrome c oxidase subunit 1 (COX1) and NAD1) and the software programs of DnaSP 5.0, Arlequin 3.0, MEGA 4.0, and NETWORK 4.5.1.6. Results showed that (a) genetic diversity of Ascaris varied with hosts and locations, but no distinct geographical distribution pattern was found, (b) a higher level of genetic diversity and differentiation was found in pig-derived populations in contrast to human-derived ones, and in populations of human-derived Ascaris from the southern regions in comparison to that from the middle and northern locations, but similar geographical difference was not observed within pig-derived populations, (c) historical population expanding was detected from a large part of human-derived Ascaris populations but not in pig-derived Ascaris, (d) a high level of gene flow was detected between human- and pig-derived Ascaris and also among human-derived populations, and (e) network analysis from haplotype of COX1 indicated an ancestral haplotype from human-derived Ascaris. In conclusion, the present study revealed new information on Ascaris on the aspects of genetic diversity, population differentiation and historical demographic patterns, gene flow, phylogenesis reconstruction, and haplotype network, discussed the results with historical demographic migration of humans and domestication of wild boar in China, and raised a different assumption about the evolutionary relationship of the two roundworms. This study should have certain enlightenment for the epidemiology and the evolutionary and taxonomy relationship of Ascaris from humans and pigs.

Serum proteomic profiling analysis of chronic arsenic exposure by using SELDI-TOF-MS technology

This study was to investigate the differences in serum proteomic profiling among subjects exposed to different levels of arsenic in drinking water and to identify proteins related to arsenicosis. A total of 148 subjects from endemic regions of China were selected and divided into low (0–8.30 μg/L), medium (16.30–37.60 μg/L) and high (140.88–273.67 μg/L) exposure groups. High exposure group consisted of subjects with and without skin lesions. Serum proteomic profiling was analyzed by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) technology. Twenty proteins were found significantly different among three groups. Further multivariate logistic regression revealed that no different proteins existed in medium versus low exposure group. A panel of five proteins, including m/ z of 15167.7, 7783.1, 7580.7, 2952.6 and 2237.4, was seen in high versus low exposure group, with a sensitivity of 93.0% and specificity of 87.5%. The same panel was found in high versus a combination of low and medium exposure groups but with somewhat lower predicting power. Only one protein was significantly different between high exposure group with and without skin lesions. The results indicate that high levels of arsenic exposure could significantly change human serum proteomic profiling, which can be detected before skin lesions occur.

Identification of Theileria uilenbergi immunodominant protein for development of an indirect ELISA for diagnosis of ovine theileriosis

Theileriosis of small ruminants in the northwest of China is a protozoan disease that restricts the development of the livestock industry. The disease is caused by infection with Theileria uilenbergi and Theilerialuwenshuni, both of which are transmitted by ixodid Heamaphysalis ticks. The development of serological tools as a means of integrated control of the disease is an urgent and important requirement. Here we describe the identification and partial recombinant expression of a T.uilenbergi immunodominant protein (TuIP), which was identified by immunoscreening of a merozoite cDNA library. Using the recombinant TuIP (rTuIP), a novel indirect ELISA was established using 329 negative serum samples to determine the cut-off value. The internal quality control revealed satisfactory stability and repeatability of the assay. Preliminary validation using 128 positive and 48 negative reference samples demonstrated that the rTuIP ELISA is able to detect T. uilenbergi infection with high sensitivity and specificity. No cross-reactivity was found in sera from animals infected with Theileria lestoquardi, Babesia sp. China or Anaplasma ovis. Furthermore, circulating antibodies were detected in sera collected from endemic regions in China. Analyses of the antibody responses of experimentally infected animals demonstrated that tick infestation resulted in a sharply rising and stronger production of specific antibodies against TuIP while inoculation with infected blood induced an earlier production of TuIP-specific antibodies. The persistence of the TuIP-specific antibodies lasted more than 100days p.i. These data indicate the usefulness of the TuIP antigen for the development of diagnostic methods and as a potential candidate for vaccine design.

Genetic variability among Schistosoma japonicum isolates from different endemic regions in China revealed by sequences of three mitochondrial DNA genes

The present study examined sequence variation in three mitochondrial DNA (mtDNA) regions, namely cytochrome c oxidase subunit 3 ( cox3), NADH dehydrogenase subunits 4 and 5 ( nad4 and nad5), among Schistosoma japonicum isolates from different endemic regions in China, and their phylogenetic relationships were re-constructed. A portion of the cox3 gene (p cox3), a portion of the nad4 and nad5 genes (p nad4 and p nad5) were amplified separately from individual trematodes by polymerase chain reaction (PCR) and the amplicons were subjected to direct sequencing. In the mountainous areas, sequence variations between parasites from Yunnan and those from Sichuan were 0.3% for p cox3, 0.0–0.1% for p nad4, and 0.0–0.2% for p nad5. In the lake/marshland areas, sequence variations between male and female parasites among different geographical locations were 0.0–0.3% for p cox3, 0.0–0.7% for p nad4, and 0.0–1.6% for p nad5. Sequence variations between S. japonicum from mountainous areas and those from lake/marshland areas were 0.0–0.5% for p cox3, 0.0–0.7% for p nad4, and 0.0–1.6% for p nad5. Phylogenetic analyses based on the combined sequences of p cox3, p nad4 and p nad5 revealed that S. japonicum isolates from mountainous areas (Yunnan and Sichuan provinces) clustered together. For isolates from the lake/marshland areas, isolates from Anhui and Jiangsu provinces clustered together and was sister to samples from Jiangxi province, while isolates from Hubei and Zhejiang province clustered together. However, isolates from different geographical locations in Hunan province were in different clades. These findings demonstrated the usefulness and attributes of the three mtDNA sequences for population genetic studies of S. japonicum, and have implications for studying population biology, molecular epidemiology, and genetic structure of S. japonicum, as well as for the effective control of schistosomiasis.

Preliminary Results of a Prospective Randomized Trial Comparing Concurrent Chemoradiotherapy Plus Adjuvant Chemotherapy With Radiotherapy Alone in Patients With Locoregionally Advanced Nasopharyngeal Carcinoma in Endemic Regions of China

A prospective randomized trial was performed to evaluate the efficacy of concurrent chemotherapy and adjuvant chemotherapy in patients with locoregionally advanced nasopharyngeal carcinoma (NPC) in endemic regions of China. Between July 2002 and September 2005, 316 eligible patients were randomly assigned to receive either radiotherapy alone (RT) or chemoradiotherapy concurrent with adjuvant chemotherapy (CRT). All patients received 70 Gy in 7 weeks using standard RT portals and techniques. The CRT patients were given concurrent cisplatin (40 mg/m(2) on Day 1) weekly during RT, followed by cisplatin (80 mg/m(2) on Day 1) and fluorouracil (800 mg/m(2) on Days 1-5) every 4 weeks (Weeks 5, 9, and 13) for three cycles after completion of RT. All patients were analyzed by intent-to-treat analysis. The two groups were well-balanced in all prognostic factors and RT parameters. The CRT group experienced significantly more acute toxicity (62.6% vs. 32%, p = 0.000). A total of 107 patients (68%) and 97 patients (61%) completed all cycles of concurrent chemotherapy and adjuvant chemotherapy, with a median follow-up time of 29 months. The 2-year overall survival rate, failure-free survival rate, distant failure-free survival rate, and locoregional failure-free survival rate for the CRT and RT groups were 89.8% vs. 79.7% (p = 0.003), 84.6% vs. 72.5% (p = 0.001), 86.5% vs. 78.7% (p = 0.024), and 98.0% vs. 91.9% (p = 0.007), respectively. This trial demonstrated the significant survival benefits of concurrent chemotherapy plus adjuvant chemotherapy in patients with locoregionally advanced NPC in endemic regions of China.