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    09 July 2021, Volume 33 Issue 3
    Endemic status of schistosomiasis in People’s Republic of China in 2020
    ZHANG Li⁃Juan, XU Zhi⁃Min, YANG Fan, DANG Hui, Li Yin⁃Long, LÜ Shan, CAO Chun⁃Li, XU Jing, LI Shi⁃Zhu, ZHOU Xiao⁃Nong
    2021, 33(3):  225. 
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    This report presented the endemic status of schistosomiasis in the People’s Republic of China at a national level in 2020, and analyzed the data collected from the national schistosomiasis prevention and control system and national schistosomiasis surveillance sites. Among the 12 provinces (municipality and autonomous region) endemic for schistosomiasis in China, Shanghai Municipality, Zhejiang Province, Fujian Province, Guangdong Province and Guangxi Zhuang Autonomous Region continued to consolidate the achievements of schistosomiasis elimination, and Sichuan and Jiangsu provinces maintained the criteria of transmission interruption, while Yunnan, Hubei, Anhui, Jiangxi and Hunan provinces maintained the criteria of transmission control by the end of 2020. A total of 450 counties (cites, districts) were found to be endemic for schistosomiasis in China, with 28 376 endemic villages covering 71 370 400 people at risk of infections. Among the 450 endemic counties (cities, districts), 74.89% (337/450), 21.87% (98/450) and 3.33% (15/450) achieved the criteria of elimination, transmission interruption and transmission control of schistosomiasis, respectively. By the end of 2020, 29 517 cases with advanced schistosomiasis were documented in China. In 2020, 11 117 655 individuals received inquiry examinations and 1 798 580 were positive; 5 263 082 individuals received serological tests and 83 179 were sero⁃positive. A total of 273 712 individuals received stool examinations and 3 were positive, including one case of acute schistosomiasis. In 2020, snail survey was performed in 19 733 endemic villages in China and Oncomelania snails were found in 7 309 villages, accounting for 37.04% of all surveyed villages, with 15 villages identified with emerging snail habitats. Snail survey covered an area of 736 984.13 hm2 and 206 125.22 hm2 snail habitats were found, including 1 174.67 hm2 emerging snail habitats and 1.96 hm2 habitats with infected snails. In 2020, 544 424 bovines were raised in the schistosomiasis⁃endemic areas of China, and 147 887 received serological examinations, with 326 positives detected, while 130 673 bovines received stool examinations, with no positives identified. In 2020, there were 19 214 patients with schistosomiasis receiving praziquantel chemotherapy, and 964 103 person⁃time individuals and 266 280 herd⁃time bovines were given expanded chemotherapy. In 2020, molluscicide treatment was performed in 136 141.92 hm2 snail habitats, and the actual area of chemical treatment was 71 980.22 hm2, while environmental improvements were performed in snail habitats covering an area of 1 464.03 hm2. Data from the national schistosomiasis surveillance sites of China showed that the mean prevalence of Schistosoma japonicum infections were both zero in humans and bovines in 2020, and no S. japonicum infection was detected in snails. The results demonstrate that the overall endemic status of schistosomiasis remains at a low level in China and the goal of the National Thirteenth Five⁃Year Plan for Schistosomiasis Control was achieved as scheduled; however, the endemic situation of schistosomiasis rebounded in local areas. Precision schistosomiasis control and intensified monitoring of the endemic situation and transmission risk of schistosomiasis are required to be performed to facilitate the progress towards elimination of schistosomiasis steadily.
    Analysis on epidemiological characteristics of current advanced schistosomiasis cases in China based on the Epidemiological Dynamic Data Collection Platform (EDDC)
    YANG Fan, XU Jing, LÜ Shan, CAO Chun⁃Li, LI Shi⁃Zhu, ZHANG Li⁃Juan
    2021, 33(3):  234. 
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    Objective To investigate the epidemiological characteristics of current advanced schistosomiasis cases in China, so as to provide the scientific evidence for the precision management and medical care of advanced schistosomiasis. Methods The baseline data pertaining to the current advanced schistosomiasis cases in China were collected from the Epidemiological Dynamic Data Collection Platform (EDDC) operated by the Chinese Center for Disease Control and Prevention. The demographic characteristics, population and regional distribution and medical care of advanced schistosomiasis cases were analyzed with a descriptive method. Results A total of 31 889 cases with advanced schistosomiasis were reported in China by the end of June, 2019, and these cases were mainly identified in Hubei Province (7 737 cases) followed by in Jiangxi Province (7 256 cases), Hunan Province (5 615 cases), Anhui Province (5 236 cases) and Jiangsu Province (2 908 cases), accounting for 90.2% (28 752/31 889) of total cases in China. The current advanced schistosomiasis cases had a male/female ratio of 1.5∶1, and a mean age of (67.0 ± 11.2) years, with 92.6% (29 521/31 889) detected in individuals at ages of over 50 years. There were 97.6% (31 109/31 889) of the cases with an educational level of junior high school and lower, and 95.2% (30 359/31 889) with an occupation of farmers. Ascites (72.6%, 23 164/31 889) and splenomegaly types (26.3%, 8 386/31 889) were predominant in current advanced schistosomiasis cases in China, and there was a significant difference in the constituent ratio of disease types among current advanced schistosomiasis cases with different age groups ([χ2] = 362.31, P < 0.01), with the ascites type as the predominant type of advanced schistosomiasis. Among the current advanced schistosomiasis cases, 88.9% (28 358/31 889) and 18.7% (5 973/31 889) had received medical treatment and surgical treatment, respectively. Conclusions The current advanced schistosomiasis cases are predominantly reported in five marshland and lake endemic provinces of China where schistosomiasis is not eliminated, and are mostly categorized as the ascites and megalosplenia types, with minor differences seen in gender and disease⁃type distributions. Precision medical care should be reinforced according to the epidemiological features of the current advanced schistosomiasis cases, and early screening and standard management and follow⁃up is required.
    Establishment of an indicator system for schistosomiasis transmission risk assessment after transmission interruption in Hubei Province based on the Delphi method
    CHEN Yan⁃Yan, LIU Jian⁃Bing, ZHONG Chen⁃Hui, XIAO Ying, WEI Feng⁃Hua, YANG Jun⁃Jing, ZHANG Wei⁃Hong, LIU Si
    2021, 33(3):  240. 
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    Objective To establish an indicator system for assessment of schistosomiasis transmission risk after transmission interruption in Hubei Province, so as to provide insights into the precise control of schistosomiasis. Methods The indicator system was preliminarily established based on data collection, literature review, expert interviews. Two rounds of expert consultation were performed. The indicator system was screened based on the importance, operability, sensitivity and comprehensive score of the indicators, and the weights of each indicator were calculated. The credibility of the Delphi method was evaluated by calculating the active coefficient of the experts, degree of expert authority and coordination levels of experts’ opinions. Results An indicator system for assessment of schistosomiasis transmission risk was preliminarily established, including 3 primary indicators, 12 secondary indicators and 44 tertiary indicators. A Delphi consultation was performed among 17 experts participating in schistosomiasis control, management and research. Following two rounds of consultation, a risk assessment indicator system was finally constructed, including 3 primary indicators, 10 secondary indicators and 35 tertiary indicators. Among the primary indicators, the variable with the highest normalized weight was the current status of schistosomiasis (0.420 2), followed by social factors (0.397 3) and natural environments (0.182 5). Among the secondary indicators, those with high combined weights included risk monitoring (0.142 3), current snail status (0.140 1), and current prevalence of human and livestock infections (0.137 8). Among the tertiary indicators, those with high combined weights included the positive rate of wild feces (0.049 8), the prevalence of snail infections (0.047 4), and the area of snail habitats submerged by floods (0.046 8). During the two⁃round consultation, the active coefficients of the experts were 85.00% and 100.00%, the degree of expert authority was both 0.75 and greater, and the coordination levels of experts’opinions were 0.405 to 0.521 and 0.592 to 0.695 (all P values < 0.05). Conclusion An indicator system for assessment of schistosomiasis transmission risk is successfully established after transmission interruption in Hubei Province based on the Delphi method, which provides insights into the identification of the schistosomiasis transmission risk and the targets for schistosomiasis control in Hubei Province.
    Molluscicidal activity of the Bacillus velezensisis Y6 strain against Oncomelania hupensis and its preliminary mechanisms of molluscicidal actions
    YANG Cheng, QIAO Yun⁃Long, LIU Hui, PAN Zhong⁃Wu
    2021, 33(3):  248. 
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    Objective To assess the molluscicidal activity of the of Bacillus Y6 strain against Oncomelania hupensis in laboratory, and to preliminarily investigate its mechanisms of molluscicidal actions. Methods Biological identification of the Y6 strain was performed based on analysis of its morphological and physiochemical features and homology analysis of the 16S rDNA gene sequence. Bacillus Y6 suspensions were formulated at concentrations of 0.005, 0.010 g/mL and 0.015 g/mL, and the molluscicidal activity of Bacillus Y6 suspensions against O. hupensis was tested in laboratory using the immersion method. In addition, the Bacillus Y6 content and glycogen content were detected in O. hupensis following exposure to Bacillus Y6 suspensions to preliminarily explore the molluscicidal mechanism of the Bacillus Y6 strain against O. hupensis. Results The colony of the Bacillus Y6 strain appeared non⁃transparent milky white, and mycoderma was produced on the surface of the nutrient agar liquid medium. The Y6 stain was Gram positive and rod⁃shaped, and the endospore was located at the center of the Bacillus Y6 strain and appeared an achromatic, transparent and refractive body, which was encapsulated by the Y6 strain. The Y6 strain was positive for the lecithinase test, and the 16S rDNA gene sequence showed a 100% homology with those of multiple B. velezensisis strains, B. amyloliquefaciens and B. subtilis. The Y6 strain was therefore identified as B. velezensisis. Following immersion in the Bacillus Y6 suspensions at concentrations of 0.005, 0.010 g/mL and 0.015 g/mL for 24, 48 h and 72 h, the mortality rates of Oncomelania snails were 28.3%, 31.7% and 81.6%, 43.3%, 58.3% and 93.3%, and 63.3%, 78.3% and 98.3%, respectively. The molluscicidal activity of the Bacillus Y6 suspensions increased with the suspension concentration and duration of immersion. Microscopy and colony counting revealed the highest Y6 content in dead snails and the lowest in living snails following immersion in Bacillus Y6 suspensions, and the mean glycogen contents were (0.68 ± 0.06), (1.09 ± 0.16) μg/mg and (2.56 ± 0.32) μg/mg in the soft tissues of dead, dying and living snails following immersion in Bacillus Y6 suspensions (F = 59.519, P < 0.05), and the mean glycogen content was significantly higher in living snails than in dead (t = 14.073, P < 0.05) and dying snails (t = 10.027, P < 0.05), while the mean glycogen content was significantly higher in dying snails than in dead snails (t = 5.983, P < 0.05). Conclusion The B. velezensisis Y6 strain shows a high molluscicidal activity against O. hupensis snails, and its invasion may cause glycogen metabolism disorders, leading to snail death.
    Effectiveness of a new health education pathway for echinococcosis control among primary school students in hyper⁃endemic regions
    KUI Yan, HAN Shuai, LIU Bai⁃Xue, TIAN Tian, YU Wen⁃Jie, YAO Ren⁃Xin, WANG Xu, WU Wei⁃Ping
    2021, 33(3):  254. 
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    Objective To investigate the effectiveness of a new health education pathway for echinococcosis control among primary school students in regions highly prevalent for echinococcosis in China. Methods Six primary schools were randomly selected from echinococcosis hyper⁃endemic regions, with 13 classes assigned to the intervention group and 9 to the control group, and all students in these 21 classes were recruited as the study subjects. Echinococcosis health education was performed through the pathway of assessing the current status⁃strengthening the building of teaching resources⁃focusing on practices in the intervention group, while routine health education was given in the control group. A questionnaire survey was performed to assess the score of echinococcosis control knowledge (including theoretical knowledge score and mean daily practical capability score) before and after the health education interventions to evaluate the effectiveness of this new health education pathway for echinococcosis control. Results The mean score of echinococcosis control knowledge was 68.86 ± 18.70 points at baseline, with the mean theoretical knowledge score of 40.97 ± 10.75 points, and the mean daily practical capability score of 27.89 ± 12.50 points. Clustering analysis showed three types of populations, including “unsatisfactory”, “learn and apply creatively”, and “rote learning”, which accounted for 24.62% (240/975), 45.74% (446/975) and 29.64% (289/975), respectively. The mean score of echinococcosis control knowledge was 81.08 ± 18.15 points in the intervention group during the final assessment, with the mean theoretical knowledge score of 43.65 ± 9.40 points, and the mean daily practical capability score of 37.43 ± 12.22 points, and both were significantly higher relative to baseline (t = -4.201 and -15.202, both P values < 0.01). The mean score of echinococcosis control knowledge was comparable between at baseline (70.55 ± 19.46 points) and final assessment (71.74 ± 19.37 points) in the control group (t = -0.87, P > 0.05). Conclusions The awareness of echinococcosis control knowledge is fair among primary school students in echinococcosis hyper⁃endemic regions; however, the capability of combining theoretical learning and practices requires to be improved. The health education mode based on the pathway of assessing the current status⁃strengthening the building of teaching resources⁃focusing on practices seems to remarkably improve the understanding of echinococcosis control knowledge among primary school students in echinococcosis hyper⁃endemic regions.
    Epidemiological characteristics and diagnosis of imported malaria cases in Zhejiang Province from 2017 to 2020
    ZHANG Xuan, RUAN Wei, CHEN Hua⁃Liang, LU Qiao⁃Yi, YAO Li⁃Nong
    2021, 33(3):  262. 
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    Objective To analyze the epidemiological features and diagnosis of imported malaria cases in Zhejiang Province from 2017 to 2020, so as to provide the scientific evidence for the management of imported malaria in the province. Methods The data of malaria cases reported in Zhejiang Province were captured from the Information Management System for Parasitic Disease Control of China Information System for Disease Control and Prevention from 2017 to 2020, and the temporal, spatial and human distribution, and initial and definitive diagnosis of imported malaria cases were descriptively analyzed. Results A total of 593 malaria cases were reported in Zhejiang Province from 2017 to 2020, and all were overseas imported cases, including 532 men and 61 women, with a mean age of 41 years. There were 93.93% of the malaria cases from African countries, and the malaria parasites infecting these cases included Plasmodium falciparum, P. vivax, P. ovale, P. malariae and mixed infections, with P. falciparum as the predominant species (76.73%, 455/593). All malaria cases received totally correct initial diagnoses in county⁃ and city⁃level centers for disease control and prevention (CDC) and entry⁃exit inspection and quarantine sectors, and the proportion of malaria cases with confirmation at the day of initial diagnosis was 41.48% (207/499) in medical institutions and 66.18% (45/68) in CDC ([χ2] = 14.779, P < 0.001). In addition, the median interval [M (QR)] of malaria cases was 1 (2) d from onset to initial diagnosis and 1 (2) d from initial diagnosis to confirmation in Zhejiang Province from 2017 to 2020, and the median interval [M (QR)] of severe malaria cases was significantly longer than that of non⁃severe cases [2 (3) d vs. 1 (2) d; Z = -3.002, P < 0.05)]. Conclusions Zhejiang Province faces great challenges of malaria control, and post⁃elimination surveillance of malaria still requires to be reinforced. Meanwhile, the awareness of seeking medical services requires to be improved among returners from malaria⁃endemic regions and the diagnostic capability of malaria requires to be improved among medical professionals.
    Effects of climate changes on the distribution of Rhipicephalus microplus in China 
    YAO Xiao⁃Yan, TIAN Na, MA Ben, ZHANG Yi, CUN De⁃Jiao, LI Lan⁃Hua
    2021, 33(3):  267. 
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    Objective To identify the environmental factors affecting the geographical distribution of Rhipicephalus microplus in China, and to examine the impact of climate changes on the distribution of R. microplus in China. Methods The national and international publications pertaining to the geographical distribution of R. microplus in China were retrieved, and the geographical location was extracted. The suitable habitats of R. microplus and the dominant environmental factors affecting the distribution of suitable habitats of R. microplus were predicted in China based on the geographical data and environmental variables using the ArcGIS 10.7 software and the maximum entropy model. Results Among the main climatic factors affecting the geographical distribution of R. microplus in China, the factors contributing more than 10% to the suitable habitats of R. microplus mainly include the annual mean precipitation (38.2%), the average temperature of the coldest quarter (28.4%) and the precipitation of the driest month (14.2%). The current suitable habitats of R. microplus were mainly found in southern China, and the high⁃, medium⁃ and low⁃suitable areas accounted for 8.6%, 13.1% and 10.5% of the total land area of China, respectively. The suitable habitats of R. microplus were predicted to increase by 399 800 km2 in China using the maximum entropy model under the RCP 4.5 emissions scenario in 2070, and the emerging suitable habitats were mainly distributed in Gansu Province, Ningxia Hui Autonomous Region, Qinghai Province, Hebei Province, Shaanxi Province, Liaoning Province, Inner Mongolia Autonomous Region, Shandong Province, Sichuan Province and Tibeten Autonomous Region. In addition, the suitable habitats of R. microplus were predicted to show an overall expansion towards northward from present to 2070. Conclusions Climate changes affect the distribution of suitable habitats of R. microplus in China, and annual mean precipitation may be a key factor affecting the distribution of suitable habitats of R. microplus.
    Surveillance of malaria vector Anopheles in Guizhou Province from 2005 to 2019
    DING Xu, SHI Wei⁃Fang, ZHANG Yu⁃Qiong, LAN Zi⁃Yao, ZHANG Ai⁃Hua, XU Jian⁃Jun, ZHOU Guang⁃Rong
    2021, 33(3):  274. 
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    Objective To understand the density, populations and habitats of malaria vector Anopheles in Guizhou Province from 2005 to 2019, so as to provide the evidence for formulating the countermeasures to tackle the risk of local transmission of imported malaria in the province. Methods The malaria vector Anopheles density and populations were monitored using human⁃bait trapping and light trapping techniques in Guizhou Province from 2005 to 2019, and all captured Anopheles was morphologically identified and counted. In addition, the distribution of Anopheles habitats was investigated. Results During the period from 2005 through 2019, the malaria vector Anopheles density increased from early June in Guizhou Province, peaked on early July and then declined, which appeared a single peak. The greatest Anopheles density was seen on early August, 2018 [57.34 mosquitoes/(person⁃night)], and the lowest density was found on late October, 2009 [1.29 mosquitoes/(person⁃night)]. The annual mean Anopheles density slowly reduced from 17.91 mosquitoes/(person⁃night) in 2005 to 12.34 mosquitoes/(person⁃night) in 2012, with a 38.02% reduction ([χ2] trend = 115.04, P < 0.01), while the annual mean Anopheles density showed a tendency towards a rise from 2017 to 2019 ([χ2] trend = 420.00, P < 0.01). The malaria vector Anopheles was captured during the period between 19:00 and 7:00 of the next day in Guizhou Province from 2017 to 2019, with the overall density appearing a tendency towards a rise followed by a decline, and the Anopheles activity was highly frequent during the period between 19:00 and 21:00. The malaria vector Anopheles was monitored for 938 times using the light trapping method in Guizhou Province from 2005 to 2019, and a total of 52 781 Anopheles mosquitoes were captured, including 49 705 An. sinensis, 804 An. minimus, 238 An. anthropophagus, and 2 034 other Anopheles mosquitoes, with a significant difference seen in the Anopheles composition ([χ2] =165.68, P < 0.01). From 2017 to 2019, a total of 24 557 Anopheles mosquitoes were captured in human housings, outdoors and livestock housings in Guizhou Province, with 67.68% captured in livestock housings and 12.01% in human housings, and there was a significant difference in the number of Anopheles mosquitoes captured from the three types of habitats ([χ2] = 55.04, P < 0.01). An. sinensis, An. minimus and An. anthropophagus were captured form all three types of habitats, in which 98.07% was An. sinensis, and 0.09% was An. anthropophagus. Conclusions The population structure of malaria vector Anopheles has changed in historically malaria⁃endemic areas of Guizhou Province, and An. sinensis has replaced An. minimus and An. anthropophagus to become the predominant malaria vector. The malaria vector Anopheles density has shown a tendency towards a rise in Guizhou Province during the recent years, and there have been a rise in the type and number of Anopheles mosquitoes, leading to a potential risk of local transmission of imported malaria. Long⁃term, persistent and extensive surveillance of malaria vectors is recommended in Guizhou Province.
    Effects of environmental factors on the distribution of suitable habitats of Ixodes ovatus in China
    MA Ben, MA Xiao⁃Yu, CHEN Hui⁃Bo, ZHANG Yi, LI Lan⁃Hua
    2021, 33(3):  281. 
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    Objective To identify the environmental factors affecting the distribution of suitable habitats of Ixodes ovatus, and to examine the effects of environmental changes on the distribution of suitable habitats of I. ovatus. Methods Data pertaining to the distribution of I. ovatus in China were captured by literature review. The distribution of suitable habitats of I. ovatus in China was simulated using the maximum entropy model with the environmental variable data and the I. ovatus distribution data. In addition, the potential distribution of suitable habitats of I. ovatus was predicted based on the 2050 and 2070 environmental data.Results The current suitable habitats of I. ovatus cover 3.11 million km2, accounting for 32.28% of the total land area of China, and they are mainly concentrated in southwestern and northwestern China. Among the screened 16 environmental factors, the standard deviation of seasonal variation of temperature, average annual precipitation and altitude were predominant environmental factors affecting the distribution of suitable habitats of I. ovatus, and these three variables contributed 76.5% to the distribution of suitable habitats of I. ovatus in China. The suitable habitats of I. ovatus were predicted to showing a tendency towards expansion to northwestern and northeastern China in 2050 and 2070, and the proportion of highly suitable habitats of I. ovatus was predicted to increase. Conclusions Moderate climate, adequate precipitation and high altitude are favorable for the survival of I. ovatus. Future climate changes may cause expansion of suitable habitats of I. ovatus in China.
    Prevalence of intestinal protozoan infections among rural children in Henan Province from 2014 to 2015
    ZHAO Dong⁃Yang, JIANG Tian⁃Tian, CHEN Wei⁃Qi, ZHANG Ya⁃Lan, DENG Yan, XU Bian⁃Li, ZHANG Hong⁃Wei, GUO Wan⁃Shen, LIN Xi⁃Meng, LI Peng, ZHAO Yu⁃Ling, YANG Cheng⁃Yun, QIAN Dan, ZHOU Rui⁃Min, LIU Ying, LI Su⁃Hua, CHEN Jian⁃She
    2021, 33(3):  287. 
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    Objective To investigate the prevalence and influencing factors of intestinal protozoan infections among rural children in Henan Province. Methods A total of 104 survey sites were sampled from 35 counties (cities) in Henan Province using the stratified cluster sampling method to investigate the prevalence of intestinal protozoan infections among rural children from 2014 to 2015. The trophozoites and cysts of intestinal protozoa were identified using the iodine staining method and the physiological saline direct smear method (one detection for one stool sample). The prevalence of intestinal protozoan infections was compared among rural children with different characteristics, and the factors affecting intestinal protozoan infections among rural children were identified. Results The overall prevalence of intestinal protozoan infections was 0.60% (40/6 771) among rural children in Henan Province from 2014 to 2015. There were 7 species of intestinal protozoa identified, and there was no species⁃specific prevalence ([χ2] = 37.732, P = 0.000). No significant differences were found in prevalence of intestinal protozoan infections among rural children in terms of gender ([χ2] = 1.793, P = 0.181), age ([χ2] = 1.443, P = 0.486), occupation ([χ2] = 0.219, P = 0.896) or ecological region ([χ2] = 1.700, P = 0.637). In addition, terrain ([χ2] = 2.311, P = 0.510), economic level ([χ2] = 4.322, P = 0.229), source of drinking water ([χ2] = 0.731, P = 0.393), eating raw vegetables ([χ2] = 1.134, P = 0.287) and deworming ([χ2] = 1.089, P = 0.297) had no remarkable effects on the prevalence of intestinal protozoan infections among rural children in Henan Province; however, the prevalence of intestinal protozoan infections varied significantly among rural children living in regions with different coverage of non⁃harmless toilets ([χ2] = 10.050, P = 0.018). Conclusion The prevalence of intestinal protozoan infections is low among rural children in Henan Province.
    Follow⁃up prognostic study on two imported patients with human African trypanosomiasis
    LI Yuan⁃Yuan, CHEN Xiao⁃Ling, LIU Qing, WANG Xin⁃Yu, CHEN Mu⁃Xin, LIU Qin
    2021, 33(3):  293. 
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    Objective To investigate the prognosis of two rare imported patients with human African trypanosomias (HAT) after treatment in a follow⁃up study, and to evaluate the therapeutic efficacy, so as to provide insights into the treatment of imported HAT patients. Methods The white blood cells in cerebrospinal fluid samples and the trypomastigotes in cerebrospinal fluid and blood samples were monitored in an imported case with Trypanosoma brucei rhodesiense infection 1, 3, 11 and 25 months post⁃treatment and in an imported case with T. brucei gambiense infection 1, 3, 8 and 12 months post⁃treatment to evaluate the therapeutic efficacy and prognosis. Results There were 1, 1, 4 and 2 white blood cells in per μL of cerebrospinal fluid in the case with T. brucei rhodesiense infection 1, 3, 11 and 25 months post⁃treatment, and there were 3, 6, 4 and 3 white blood cells in per μL of cerebrospinal fluid in the case with T. brucei gambiense infection 1, 3, 8 and 12 months post⁃treatment. In addition, no trypomastigotes were identified in the cerebrospinal fluid or blood samples of either case with T. brucei rhodesiense or T. brucei gambiense infection. Conclusion Following standardized treatment, two imported cases with human African trypanosomiasis cases recover satisfactorily, without any signs of relapse.
    Chromosomal karyotypes and C⁃band analysis of Triatoma rubrofasciata in China 
    WANG Meng⁃Xia, LIU Qin, ZHANG Yi, ZHU Dan
    2021, 33(3):  297. 
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    Objective To investigate the karyotypes and C bands of Triatoma rubrofasciata in China, so as to understand its chromosome number, morphology and C⁃band staining of T. rubrofasciata. Methods The testis specimens were sampled from male T. rubrofasciata collected from Shunde City, Guangdong Province, prepared into slides of metaphase chromosomes and subjected to Giemsa staining and C⁃band staining. The morphology of metaphase chromosomes and the location of heterochromatin were observed using microscopy, and the long arm and short arm of each chromosome and total chromosome length were recorded to analyze the karyotypes and C bands of T. rubrofasciata. Results The male T. rubrofasciata presented a chromosome number of 2n = 25, including 22 autosomes and 3 sex chromosomes. The relative length of chromosomes ranged from 3.59% to 12.76%, the arm ratio was 1.06 to 1.24, and the centromere index was 44.76% to 48.47%. All chromosomes were metacentric chromosomes and the karyotype formula was 2n = 22 metacentric + X1X2Y, and the C bands varied on different chromosomes. No heterochromatin was found in the X chromosome, and the overall staining appeared pale, while heterochromatin was detected in all regions of the Y chromosome, and the overall staining appeared dark. In addition, heterochromatin was present in both ends of the autosome. Conclusions The male T. rubrofasciata presents a chromosome number of 2n = 25 in China, and the karyotype formula is 2n = 22 metacentric + X1X2Y. C⁃banding shows dark staining of the Y chromosome, pale staining of the X chromosome, and dark staining of both ends of the autosome. Our data may provide insights into the investigation on the origin, evolution and gene mapping of T. rubrofasciata in China.
    Analysis of invalid patents associated with schistosomiasis control filed by Chinese applicants
    XIONG Yan⁃Hong, XU Xue⁃Nian, ZHENG Bin
    2021, 33(3):  301. 
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    The invalid patents associated with schistosomiasis control were retrieved in the Chinese Patent Database of China National Intellectual Property Administration, the Baiten database and the incoPat database, and the overall trends, legal status, types, patent indexing and technical fields of all retrieved invalid patents were analyzed. As of December 30, 2020, there were totally 859 patents relating to schistosomiasis control, and 512 were invalid patents, with an invalid rate of 59.6%. The number of patent applications and invalid patents peaked in 2018, including 71 patent applications and 53 invalid patents. Among the 511 schistosomiasis control⁃related invalid patents with complete records, there were 425 invention patents, 81 utility model patents and 5 design patents, and 219 patents (42.9%) were invalid due to the termination of the patented right and 292 (57.1%) due to loss of the right for patent applications. The major technical points included medicines (chemicals), basic research, devices and detections, and the specialized fields were mainly concentrated in A61P33, G01N33, C12N15, C07K14 and A01N65. Our data demonstrate a high invalid rate of patents relating to schistosomiasis control in China. Secondary development and mining of the invalid patents in relation to schistosomiasis are recommended to make use of their values in the national schistosomiasis elimination program of China.
    Seroprevalence of Toxoplasma gondii infections among patients with autoimmune diseases
    CAO Ping⁃Ping, YE Xu⁃Fang, QIAN Chun⁃Yan
    2021, 33(3):  305. 
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    Objective To understand the seroprevalence of Toxoplasma gondii infections among patients with autoimmune diseases, so as to provide the scientific evidence for the management of toxoplasmosis in patients with autoimmune diseases. Methods A total of 237 patients with definitive diagnosis of autoimmune disease were selected as the study subjects, including 79 cases with systemic lupus erythematosus, 71 cases with rheumatoid arthritis and 87 cases with inflammatory bowel disease, while 237 healthy volunteers served as controls. The serum anti⁃T. gondii IgG antibody was detected using enzyme⁃linked immunosorbent assay (ELISA) in patients with autoimmune diseases and healthy controls, and the detection of serum IgG antibody against T. gondii was compared between the autoimmune disease patients and healthy controls. Results The seroprevalence of serum IgG antibody against T. gondii was significantly greater in patients with autoimmune diseases than in healthy controls (29.96% vs. 4.22%; [χ2] = 55.41, P < 0.01), and the seroprevalence of T. gondii infection was all significantly higher in patients with systemic lupus erythematosus (31.65%), rheumatoid arthritis (23.94%) and inflammatory bowel disease (33.33%) than in healthy controls ([χ2] = 45.25, 26.58 and 50.95; all P values < 0.01). Conclusion The seroprevalence of anti⁃T. gondii IgG antibody is significantly higher in patients with autoimmune diseases than in healthy controls, and T. gondii infection may be a potential risk factor for the development of systemic lupus erythematosus, rheumatoid arthritis and inflammatory bowel disease.
    Evaluation of the effectiveness of community health education for the prevention and control of retransmission of imported malaria in Zhangjiagang City
    HUANG Feng, WANG Xue⁃Dong, JIANG Ling, QIU Hai⁃Yan
    2021, 33(3):  308. 
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    Objective To increase the awareness of malaria prevention and control among people going abroad and returners, so as to prevent the local retransmission of oversea imported malaria.Methods Health education interventions for malaria control were given to people going abroad and returners in communities, and the changes of malaria prevention and control knowledge and medical⁃seeking behaviors were observed among the target populations. Results There were 367 people going abroad and oversea returners from malaria⁃endemic areas in Zhangjiagang City from July 2018 to December 2019, and 18 imported malaria cases were found. Following the implementation of community health education, the awareness of malaria prevention and control knowledge increased significantly from 35.09% to 93.05% among the target populations (χ2 = 78.130, P < 0.01), and the proportions of carrying anti⁃malarial drugs and administration of anti⁃malarial drugs for emergency treatment increased from 12.14% and 11.46% to 26.79% and 26.79% (χ2 = 8.793 and 9.834, P < 0.05), respectively. In addition, the mean duration from malaria onset to the definitive diagnosis reduced from (5.86 ± 4.45) days to (3.11 ± 1.28) days (U = 64.000, P < 0.05). Conclusion Community health education based on the precision community administration is an effective approach for malaria control in current era.
    Application of health economics assessment techniques in the prevention and control of important infectious diseases: a review
    WU Ling⁃Ling, ZHOU Xiao⁃Nong, JIA Tie⁃Wu, XU Jing
    2021, 33(3):  311. 
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    Due to the relative shortage of health resources, rational allocation and utilization of health resources is critical to achieving the maximum economic benefits in developing countries, which requires a health economic assessment to meet the needs to balance the competitive requirements of cost reduction and effectiveness enhancement. This review describes the advances in applications of health economic assessment techniques in four major infectious diseases, including AIDS, tuberculosis, hepatitis B and schistosomiasis. Currently, there is no standard economic assessment in the prevention and control of infectious diseases, and notably, the transparency of cost research is limited, which may affect the popularization of the study conclusions. Further health economic assessments of infectious diseases are required to improve the quality, standard and transparency of the economic evaluation through formulating strategies, to improve the standardization of studies, to improve the popularization of the study conclusions and to improve the applicability of the economic evaluation for policies.
    Progress of researches on Fasciola and fascioliasis in Yunnan Province
    XIANG Zheng, SHEN Li⁃Jie, JIA Xue⁃Mei
    2021, 33(3):  317. 
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    Fascioliasis is a zoonotic parasitic disease that seriously endangers human health and hinders socioeconomic development. Fasciola mainly infects ruminants, such as cattle and sheep. However, there has recently been a rise in the number of human cases with fascioliasis with the improvements of diagnostic techniques. During the past decades, sporadic cases of fascioliasis were predominantly identified; however, there were outbreaks of fascioliasis in Yunnan Province, which has been paid much attention. The review summarizes the advances in the distribution of Fasciola species and the progress of researches on fascioliasis in Yunnan Province.
    Progress of researches on the application of risk assessment models in assessment of the schistosomiasis transmission risk
    WANG Can, ZHANG Li⁃Juan, LÜ Shan, XU Jing
    2021, 33(3):  320. 
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    With the deepening of the schistosomiasis research, risk assessment models have been widely used in schistosomiasis research and control. This paper reviews the theoretical basis and applications of common schistosomiasis risk assessment models and the Bayesian model, so as to provide insights into national schistosomiasis elimination program in China.
    Plasmodium falciparum infection complicated by bronchopneumonia in a peacekeeper: a case report
    LI Kai, LIU Li⁃Jie, DENG Yun⁃Dian, WU Jin⁃Hui, LU Jun
    2021, 33(3):  325. 
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    Malaria is an acute febrile illness caused by Plasmodium. In Africa where the burden of malaria is extremely high, febrile symptoms caused by respiratory tract infections may challenge the diagnosis of malaria, and patients with unclear diagnosis and administration of antimalarial drugs require more attention. Hereby, a peacekeeper with Plasmodium falciparum infection complicated with bronchopneumonia was reported.
    Treatment of Chilomastix mesnili infection with traditional Chinese medicine: a case report
    LIANG Qin, LU Yu⁃Bei, FU Hui, YAN Xue⁃Bo, MIAO Feng
    2021, 33(3):  327. 
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    This paper reports a case with Chilomastix mesnili infections, and summarizes the diagnosis and treatment with traditional Chinese medicine.