Temporal trends in disease burden of major human parasitic diseases in China from 1990 to 2019 / 中国血吸虫病防治杂志

Objective To analysize the temporal trends in the disease burden of major human parasitic diseases in China from 1990 to 2019, so as to provide the evidence for improving the parasitic disease control strategy in China.. Methods The disability-adjusted life years (DALYs) of malaria, intestinal nematode infections, schistosomiasis, food-borne trematodiases, cysticercosis and echinococcosis in China from 1990 to 2019 were captured from the Global Burden of Disease Study 2019 (GBD 2019), and age- and gender-specific DALYs of parasitic diseases were estimated. The temporal trends in DALYs of malaria, intestinal nematode infections, schistosomiasis, food-borne trematodiases, cysticercosis and echinococcosis were evaluated in China from 1990 to 2019 using average annual percent change (AAPC) with Joinpoint regression analysis. Results The DALYs were 643 836.42 person-years due to food-borne trematodiases, 156 853.03 person-years due to cysticercosis, 79 764.62 person-years due to schistosomiasis, 70 989.73 person-years due to intestinal nematode infections, 4 258.61 person-years due to echinococcosis and 264.86 person-years due to malaria in China in 2019, respectively. The overall DALYs of six parasitic diseases were higher among men (546 441.93 person-years) than among women (409 525.33 person-years), and were greater among adults at ages of 14 to 65 years (684 780.84 person-years) than among children at 14 years and lower (35 437.38 person-years) and the elderly at ages of 65 years and older (235 749.04 person-years). During the period from 1990 to 2019, food-borne trematodiases were the leading cause of DALYs among the six parasitic diseases, and cysticercosis shifted from the fourth leading cause in 1990 to the second leading cause of DALYs in China in 2019, while intestinal nematode infections shifted from the second leading cause in 1990 to the fourth leading cause of DALYs in 2019. The DALYs of major human parasitic diseases appeared an overall tendency towards a decline in China from 1990 to 2019, with the fastest drop seen in DALYs due to malaria (AAPC = −19.6%, P = 0.003), followed by due to intestinal nematode infections (AAPC = −8.2%, P < 0.001) and schistosomiasis (AAPC = −3.1%, P < 0.001), and a slow decline was seen in the DALYs of food-borne trematodiases (AAPC = −1.0%, P < 0.001), while there were no significant decrease in the DALYs of echinococcosis (AAPC = −0.5%, P = 0.264) and the DALYs of cysticercosis appeared a tendency towards a rise (AAPC = 0.7%, P < 0.001). Conclusions The disease burden of major human parasitic diseases appeared an overall tendency towards a decline in China from 1990 to 2019, with a high disease burden seen due to food-borne parasitic diseases, no remarkable reduction seen in echinococcosis, and a tendency towards a rise seen in cysticercosis. It is recommended to focus on echinococcosis control, and continue to consolidate the control achievements of other major human parasitic diseases in China; meanwhile, the surveillance and prevention of food-borne parasitic diseases should be reinforced.

Thrombosis after establishing internal jugular vein channel in one burn patient / 中华烧伤杂志

On September 7th, 2017, one female patient, aged 48 years with deep partial-thickness flame burn on face, upper limbs, trunk, and lower limbs of 40% total body surface area was admitted to the First People′s Hospital of Foshan City. After admission, active fluid replacement, anti-infection, nutritional support, and other treatments were performed. After debridement and skin grafting for 3 times and blood transfusion for 2 times, the patient recovered well. On the 20th day post admission, sudden heartbeat and respiratory arrest happened, and the patient died after ineffective rescue. Autopsy showed that thrombus formed in right internal jugular vein and deep veins of lower extremities, and vascular lumina of the bilateral pulmonary artery. The direct cause of death was acute pulmonary thromboembolism, but whether the embolus originated from deep vein of lower extremity or right internal jugular vein was not clear. This case suggests that clinician should not only pay attention to the prevention of deep venous thrombosis of lower extremities of burn patients, but also the possibility of internal jugular vein thrombosis, especially for patients with internal jugular vein access.

Morphological analysis of cardiac rupture due to blunt injury, cardiopulmonary resuscitation and myocardial infarction in forensic pathology / 南方医科大学学报

OBJECTIVE@#To analyze the morphological features and forensic pathological characteristics of cardiac ruptures of different causes for their differential diagnosis.@*METHODS@#We analyzed the data of 44 autopsy cases of cardiac rupture from 2014 to 2017 in our institute, including 11 cases caused by blunt violence with intact pericardium, 4 caused by cardiopulmonary resuscitation (CPR), 9 by myocardial infarction, and 20 by aorta dissection rupture.The gross features and histopathological characteristics of cardiac rupture and pericardial effusion were analyzed and compared.@*RESULTS@#Cardiac ruptures caused by blunt violence varied in both morphology and locations, and multiple ruptures could be found, often accompanied with rib or sternum fractures; the volume of pericardial effusion was variable in a wide range; microscopically, hemorrhage and contraction band necrosis could be observed in the cardiac tissue surrounding the rupture.Cardiac ruptures caused by CPR occurred typically near the apex of the right ventricular anterior wall, and the laceration was often parallel to the interventricular septum with frequent rib and sternum fractures; the volume of pericardial blood was small without blood clots; microscopic examination only revealed a few hemorrhages around the ruptured cardiac muscular fibers.Cardiac ruptures due to myocardial infarction caused massive pericardial blood with blood clots, and the blood volume was significantly greater than that found in cases of CPR-induced cardiac rupture ( < 0.05);lacerations were confined in the left ventricular anterior wall, and the microscopic findings included myocardial necrosis, inflammatory cell infiltration, and mural thrombus.Cardiac tamponade resulting from aorta dissection rupture was featured by massive pericardial blood with blood clots, and the blood volume was much greater than that in cases of cardiac ruptures caused by blunt violence, myocardial infarction and CPR ( < 0.05).@*CONCLUSIONS@#Hemorrhage, inflammatory cell infiltration, and lateral thrombi around the cardiac rupture, along with pericardial blood clots, are all evidences of antemortem injuries.

Establishment of response system to emergency parasitic disease affairs in China / 中国血吸虫病防治杂志

China's prevention and control of parasitic diseases has made remarkable achievements. However,the prevalence and transmission of parasitic diseases is impacted by the complicated natural and social factors of environment ,natural disas-ters,population movements,and so on. Therefore,there are still the risks of the outbreak of emergency parasitic diseases af-fairs,which may affect the control effectiveness of parasitic diseases and endanger the social stability seriously. In this article , we aim at the analysis of typical cases of emergency parasitic disease affairs and their impacts on public health security in China in recently years,and we also elaborate the disposal characteristics of emergency parasitic disease affairs,and propose the estab-lishment of response system to emergency parasitic disease affairs in China,including the organizational structure and response flow path,and in addition,point out that,in the future,we should strengthen the system construction and measures of the re-sponse system to emergency parasitic disease affairs,so as to control the risk and harm of parasitic disease spread as much as possible and to realize the early intervention and proper disposal of emergency parasitic disease affairs.

Integration and demonstration of key techniques in surveillance and fore-cast of schistosomiasis in Jiangsu Province III Development of a machine simulta-neously integrating mechanized environmental cleaning and automatic mollusciciding / 中国血吸虫病防治杂志

Objective To develop a machine simultaneously integrating mechanized environmental cleaning and automatic mollusciciding and to evaluate its effectiveness of field application,so as to provide a novel Oncomelania hupensis snail control technique in the large?scale marshlands. Methods The machine simultaneously integrating mechanized environmental clean?ing and automatic mollusciciding,which was suitable for use in complex marshland areas,was developed according to the mech?anization and automation principles,and was used for O. hupensis snail control in the marshland. The effect of the machine on environmental cleaning and plough was evaluated,and the distribution of living snails was observed at various soil layers follow? ing plough. The snail control effects of plough alone and plough followed by mollusciciding were compared. Results The ma?chine could simultaneously complete the procedures of getting vegetation down and cut vegetation into pieces,plough and snail control by spraying niclosamide. After plough,the constituent ratios of living snails were 36.31% ,25.60% ,22.62% and 15.48% in the soil layers at depths of 0-5,6-10,11-15 cm and 16-20 cm respectively,and 61.91% living snails were found in the 0-10 cm soil layers. Seven and fifteen days after the experiment,the mortality rates of snails were 9.38% and 8.29% in the plough alone group,and 63.04% and 80.70% in the plough + mollusciciding group respectively(c27 d = 42.74,c215 d =155.56,both P values < 0.01). Thirty days after the experiment,the densities of snails were 3.02 snails/0.1 m2 and 0.53 snails/0.1 m2 in the soil surface of the plough alone group and the plough + mollusciciding group,which decreased by 64.92% and 93.60% ,respectively,and the decrease rate of snail density was approximately 30% higher in the plough + mollusciciding group than that in the plough alone group. Conclusions The machine simultaneously integrating mechanized environmental cleaning and automatic mollusciciding achieves the integration of mechanical environmental cleaning and automatic niclosamide spraying in the complex marshland areas,which provides a novel technique of field snail control in the large?scale setting in Chi?na.

Role of goat in transmission of schistosomiasis japonicaⅣSchistosome develop-ment in goat and egg count and distribution in goat feces / 中国血吸虫病防治杂志

Objective To describe the growth and development of Schistosoma japonicum in goat and the intensity and tem?poral distribution of eggs excreted by goat feces,so as to provide baseline data for the control and elimination of the role of goat in the transmission of schistosomiasis. Methods The goat animal models of schistosomiasis were established,and stool sam?ples were collected for parasitological examinations. The number of adult worms recovered,variation of schistosomes in goat at different time points post?infection,number of eggs in schistosomes,variation in number and temporal profiles of eggs excreted from goat feces were observed. Results Of the 6 schistosome?infected goat,415 adult worms were recovered,with a mean adult worm recovery of 34.58%(range,23.00%to 45.50%). Among the 5 goat infected with 200 cercariae each,47,93,77, 74 and 73 adult worms were recovered 2,5,8,11 and 14 months post?infection,respectively. There were(200.00 ± 42.33), (226.20±45.88),(168.20±25.85),(183.80±55.13)and(190.80±53.53)eggs detected in female schistosomes. The mean pre?patent period of eggs excreted by 10 infected goat was(37.7±3.02)d. From 2 to 14 months post?infection,7 batches of goat fe?ces were hatched,and there were 30,23,14,1 and 2 times for miracidium intensity of“++++”,“+++”,“++”,“+”and“-”, respectively,with 42.86%,32.86%,20.00%,1.43%and 2.86%constituent ratios of miracidium intensity. Conclusions Ap?proximately 1/3 S. japonicum cercariae may develop to adults in goats post?infection,and the prepatent period of eggs is(37.7± 3.02)d. There is no remarkable decrease seen in the number of adult worms,eggs in female schistosomes and eggs in goat feces within 14 months post?infection. Our findings suggest a long duration for infected goat in the transmission of schistosomiasis ,and there is no evidence to prove the“self?cure”phenomenon in goat,indicating that goat is an important source of infection for schistosomiasis japonica.

Surveillance and risk assessment system of schistosomiasis in Jiangsu Prov-inceⅢRisk of schistosomiasis transmission in the area along the Yangtze River in Yang-zhou City / 中国血吸虫病防治杂志

Objective To evaluate the potential risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City,so as to provide evidences for establishing a post?transmission surveillance system for schistosomiasis in marsh?land regions. Methods The water infectivity,floating boatmen and fishermen infection,reservoir host infection and wild feces contamination were investigated in five districts/counties along the Yangtze River in Yangzhou City,including Guangling,Hanji?ang,Jiangdu,Yizheng and Development Zone,and the transmission factors and risky characteristics were assessed after inter?ruption of schistosomiasis transmission in marshland regions. Results A total of 15 key water regions were identified in the area along the Yangtze River in Yangzhou City in 2015. A total of 1 500 sentinel mice were placed,after breeding,their overall sur?vival rate was 99.33%;1 490 were dissected,with no schistosome infection. Of the 5 576 floating boatmen and fishermen exam?ined,no schistosome infection was observed,and among the 3 566 domestic animals(including 171 cattle,1 895 sheep and 1 500 pigs),no infections were detected. During the period between January and March,2016,there were 3 200 mouse traps placed on 8 marshlands,and 62 wild mice were captured from 6 marshlands,with a capture rate of 1.94%,and no schistosome?infected wild mice were seen. In addition,there were 35 pieces of fresh wild feces captured from 7 marshlands,including 11 pieces of bovine feces(31.43%),17 pieces of sheep feces(48.57%),2 pieces of dog feces(5.71%)and 5 pieces of other feces (14.29%),and no infections were detected. Conclusions There is a low risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City. However,the contamination of feces from bovine and sheep that are freely pastured on marshlands is a big threat to schistosomiasis control.

Integration and demonstration of key techniques in surveillance and fore-cast of schistosomiasis in Jiangsu Province I Layout and effect of the demonstra-tion sites for schistosomiasis surveillance and forecast / 中国血吸虫病防治杂志

Objective To explore and integrate the key techniques used in the surveillance and forecast of schistosomiasis in the water regions along the Yangtze River,so as to provide technical support for identifying rapidly the risk of schistosomiasis transmission and implementing control measures targeting the risk. Methods According to the distribution of water systems and water regions along the Yangtze River in Jiangsu Province,the demonstration sites for surveillance and forecast of schistoso? miasis were set across the province,where the integration and demonstration of the techniques regarding monitoring of Schistoso?ma japonicum infection in sentinel mice,human and animal activities,release of forecast information,and emergency treat?ment of water regions at risk of infection were performed. The pattern of human and animal activities was compared with the S. ja?ponicum infection in sentinel mice in the demonstration sites,and the operability of the release of information and emergency treatment of the risk of S. japonicum infection was evaluated. Results A total of 50 demonstration sites for surveillance and forecast of schistosomiasis were set in fixed anchor points,opening of the navigation lock to the Yangtze River,freight terminal, agritainment places,ferry,large construction places,and places for guaranteeing the Youth Olympic Games in 23 counties(dis?tricts)of 5 cities,Jiangsu Province. During the period between May and September,2014,the infectivity of water body was monitored by using 5 batches of sentinel mice,with a 99.06%(4 954/5 001)gross recovery rate of mice. S. japonicum infection was detected in a demonstration site,and an infected mouse was found,with a 0.02%(1/4 933)gross positive rate of sentinel mice. The field survey showed 2 088 person?times contacting water,including 91.95%(1 920/2 088)contacting water due to the production such as capturing fish,harvesting and cultivating crops,and repairing and building boats,and 8.05%(168/2 088)contacting water due to the life activity,such as fishing,washing vegetables and playing with water. The people contacted water predominantly in August and September(49.57%). A total of 859 boats containing 1 877 boatmen were observed,68.22%(586/859)of which were fishing boats containing 1 306 fishermen(69.58%). There were 32 sheep found in 4 demonstration sites,and 3 sheep were seen in the demonstration site with infected sentinel mouse. Four blue forecasts(emergence of water con?tact)and one orange forecast(S. japonicum?infected sentinel mouse detected)were released across the province,with one fore?cast map released which showed 5 sites with fishing and one site with sheep grazing,one emergency response system initiated, mollusciciding implemented in 10 hm2 high?risk regions,120 sheep grazed in fence,and 35 fishermen given health?education materials,schistosomiasis examination and preventive therapy. In addition,no acute schistosomiasis occurred in the demonstra?tion site with S. japonicum?infected sentinel mice. Conclusions The integration and demonstration of the techniques regarding monitoring of S. japonicum infection in sentinel mice,human and animal activities,release of forecast information,and emer?gency treatment of water regions at risk of infection provides an effective approach for the large?scale surveillance and forecast of schistosomiasis.

Surveillance and risk assessment system of schistosomiasis in Jiangsu Prov-ince I Distribution of surveillance site and effectiveness of the system / 中国血吸虫病防治杂志

Objective To establish the surveillance and risk assessment system of schistosomiasis in Jiangsu Province,so as to provide technical support for timely understanding of the risk of schistosomiasis transmission and implementation of target-ed control measures. Methods The surveillance sites of schistosomiasis were assigned according to the epidemic status and en-demic type of schistosomiasis as well as the characteristics of the water system,and the prevalence of Schistosoma japonicum in humans and domestic animals,and snail status were investigated. In addition,the quality control of serum detection of S. japon-icum infections was performed. The prevalence of human and animal S. japonicum infections,snail status and missing diagnosis of serum detection were analyzed and compared among regions. Results A total of 27 surveillance sites of schistosomiasis were set up in 26 counties of 10 cities,Jiangsu Province,including 14 sites in transmission-interrupted villages and 13 sites in trans-mission-controlled villages,and 15 sites in marshland and lake regions,9 sites in plain regions with water network and 3 sites in mountainous region. In the 27 surveillance sites,a total of 16 617 residents were screened for S. japonicum infection by using dipstick dye immunoassay(DDIA),and 326 were sero-positive,with a sero-prevalence of 1.96%(2.17%for men and 1.8%for women). Of the 326 individuals undergoing parasitological examination,2 positive cases were detected in the marshland and lake region,with a S. japonicum human prevalence of 0.01%. Of the 762 floating population detected,10 were positive for blood test,with a sero-prevalence of 1.31%,and no egg-positive individuals were detected. No infection was found in the 476 do-mestic animals. Of the 746 settings surveyed,a total of 240.7 hm2 snail area was detected,with a mean snail density of 0.06 snails/0.1 m2,and no infected snails were found. There were 780 quality-control sera detected in 26 surveillance sites of schisto-somiasis,and the gross coincidence rate was 95.13%,with misdiagnosis rate of 1.28%and missing diagnosis rate of 19.23%. Conclusion The surveillance sites of schistosomiasis show reasonable distribution in Jiangsu Province,and the endemic situa-tion of schistosomiasis appears a low level in the whole province.

Surveillance and risk assessment system of schistosomiasis in Jiangsu Prov-ince II Surveillance pattern and effect of Oncomelania hupensis snail status in Dongtai City,Jiangsu Province / 中国血吸虫病防治杂志

Objective To explore the method of Oncomelania hupensis snail surveillance in transmission?interrupted re?gions of schistosomiasis,so as to provide a new pattern for the surveillance of snail status in the transmission?interrupted areas. Methods In Dongtai County,north of Jiangsu Province where the transmission of schistosomiasis was interrupted,the surveil?lance of snail status was performed by means of the village?level general survey,village?level sampling survey,snail survey in key settings of township and county,and snail reporting by residents. In addition,quality?control snail sites were set up for quali?ty control. The effectiveness and cost of the four methods of snail surveillance was compared. Results A total of 163 079 set?tings and 22 785.62 hm2 were surveyed in Dongtai County from 2008 to 2013,and 89 residual snail breeding sites were found, with a snail area of 1.48 hm2. The patterns of village?level general survey,village?level sampling survey,and snail survey in key settings of township and county were employed for investigation of 94 550,45 033 and 23 496 settings,consisting of 57.98%, 27.61%and 14.41%of total settings,and 2,0 and 6 settings were found with snails,with 0.021/thousand,0,and 0.255/thou?sand detection rates of settings with snail breading sites,respectively. The pattern of snail survey in key settings of township and county was more effective than that of village?level survey to detect snail breeding sites(χ2 =19.158,P=0). The recovery rate of quality?control snail breeding sites was 52.56%,38.27%and 73.62%for the three patterns of snail survey,respectively,and the pattern of snail survey in key settings of township and county showed a higher quality for snail survey than that of village?lev?el survey(χ2 =111.597 and 85.991,both P=0). During the period from 2008 to 2013,289 person?times reported 279 sus?pected snail habitats and 1 501 living snails,and no Oncomelania snails were found. During the 6?year period,there were 1617.5,964.7 and 527.7 thousand RMB invested for village?level general survey,village?level sampling survey,and snail sur?vey in key settings of township and county,and the cost of snail survey per hm2 was 129.88,133.6 and 162.57 RMB/hm2,re?spectively. The cost of village?level general survey and snail survey in key settings of township and county to detect a snail?breed?ing site was 808 800 and 88 000 RMB,respectively(t=12.850,P=0.000),and the cost of snail survey in key settings of town?ship and county was 10.88%of that of village?level general survey. Conclusion The snail survey in key settings of township and county is a highly effective and high?quality method for snail surveillance,which may serve as a prior way for the surveil?lance of snail status in the transmission?interrupted areas of schistosomiasis.

Surveillance and forecast system of schistosomiasis in Jiangsu Province ⅥDetection technology of water infectivity based on enrichment of Schistosoma japonicum cercariae on water surface / 中国血吸虫病防治杂志

Objective To explore the enrichment technique of Schistosoma japonicum cercariae on the water surface,so as to establish a new method combined with the existing technology to detect the cercarial infested water body quickly and sensitive-ly. Methods Soybean oil,gasoline,kerosene and isophorone were screened as expanding agents. The cercariae were enriched by the thrust of the expanding agents when diffusing on the water surface,and PE adsorption film and C-6 film were applied to seize them so as to determine the infectivity of the water quickly. The relationship between the dose of expanding agents and dif-fusion radius were explored. Results Gasoline,kerosene and isophorone were suitable expanding agents,and the diffusion ef-fect of isophorone was the best. After the enrichment by the expanding agents,the detection rate of cercariae of the method seiz-ing cercariae with the film significantly improved in the water. Conclusion This new method could effectively improve the de-tection rate of the cercarial infested water and is suitable for the low-degree infested water.

Dynamic analysis of Oncomelania snail distribution in Jiangsu Province,2004-2008 / 中国血吸虫病防治杂志

Objective To analyze the characteristics and changes of Oncomdania snail distribution in regions with different epidemic types and degrees of Jiangsu Province,so as to provide the evidence for implementing the feasible schistosomiasis control strategy.Methods A retrespeetive survey was performed,and the 5-year database of snail status in Jiangsu Province was established based on the collected reports of snail habitat cards and schistosomiasis control in Jiangsu Province from 2004 to 2008.The changes of snail areas,infected snail aroas,infection rates of snails in different years were analyzed,and tIIe annual vailations of snail areas,infected snail areas and infection rates of snails in areas with different epidemic types and degrees were eomparedI Results The actual snail areas and infected snail areas decreased by 3 799.86 hm~2 and 2 006.35 hm~2.respectively in Jiangsu Province.2006-2008.with the annual meaan decreasing rates of 9.64% and 18.83%.Among them,the actual snail areas in marshland and lake regions,water net regions and mountainous regions decreased by 3 546.10.209.19 hm~2 and 44.57 hm~2,respectively,with the annual meall decreasing rates of 9.59%,10.29% and 11.18%,respectively.An area of 22.02 hm~2 of new snail habitatswas detected during the 5 years,and thewater net regions accounted for 89.24%.Theproportions of actual snail areas in historical snail ale,as were between 2.77% and 5.36%.Among them.the proportions of actual snail areas in historical accumulative snail area8 in transmission-uncontrolled.trailsmission-controlled and transmission-interrupted areas were 13.29%-22.82%,0.88%-3.54% and 0.14%-0.32%,respectively,and there were significant differences among them(P<0.01).The constituent ratios of the actual snail areaswere 93.79%-95.60%.3.67%-5.45% and 0.73%-1.01%, respectively in marshland and lake regions,water net regions and mountainous regions from 2004 to 2008.The infection rate of snails in Jiangsu Province reduced from 0.15% in 2004 to 0.02% in 2008,with a reduction rate of 85.50%(P<0.01).The constituent ratios of infected snail areas in transmission-uncontrolled, transmission-controlled and transmission-interrupted areas were 98.15%-100%,0-0.81%, and 0-1.43%,respectively.Conclusions As a whole,there is a decreasing tendency of snail areas and infected snail areas in Jiangsu Province.and the snail control has been consohdated step by step in transmission-interrupted areas.The effective control of snails in marshland and lake regions and infected snails in transmission-uncontrolled areas are the key points in the future schistosomiasis control of Jiangsu Province.

Investigation on compliance of forbidden depasturing livestock on marshland with Oncomelania snails in schistosomiasis endemic areas / 中国血吸虫病防治杂志

Objective To study the compliance of forbidden depasturing livestock on the marshland with Oncomelania snails in schistosomiasis endemic areas. Methods According to 3 levels of human infection rates as > 10% ,5%-10% and <5% , 2 204 residents selected randomly from the schistosomiasis endemic villages were sampled with the stratified cluster sampling method in Hunan, Hubei, Jiangxi, Anhui, Jiangsu, Sichuan and Yunnan provinces, and investigated by questionnaire. The contents of the questionnaire included the recognition and implementation of forbidden depasturing livestock on marshland with Oncomelania snails and breeding livestock in bam. Results A total of 78.4% residents agreed forbidden depasturing livestock on marshland with snails, but 3. 7% residents disagreed it. A total of 83. 9% residents considered the relationship between breeding livestock in bam and schistosomiasis control, but 3. 1% residents thought that it was no relationship. The main reasons of depasturing livestock on marshland with Oncomelania snails were the high cost of breeding livestock in bam (36. 2% ) , unaccustomed (26.4% ) and no room for breeding livestock in bam (25.4% ). Conclusion Forbidden depasturing livestock on the marshland with Oncomelania snails should be strengthened according to the local economic, nature environment, agriculture, residents'culture degree and agriculture habit.

Use of landsat TM satellite surveillance data to measure the impact of the 1998 flood on snail intermediate host dispersal in the lower Yangtze River Basin.

To assess the impact of the 1998 flood on snail distribution in the lower Yangtze River Basin, two study areas were selected, one in the Poyang Lake region, and the other along the Yangtze River in Jiangsu province. Using image analysis software, geocoded Landsat TM data were used to create TNDVI maps based on the formula TNDVI=Sqrt[(band4-band3/band4+band3)+0.5]. The images taken in the flood season were classified to produce a map depicting water and land. The images taken during springtime were processed and classified based on TNDVI. Composite images were created based on the time difference analysis, combining the flood season maps and spring vegetation maps to produce a map in which potential snail habitats were identified. When compared with ground survey data collected in the spring of 2000, the correspondence rate between potential snail habitats identified by image analysis of 1998-1999 Landsat TM data and ground survey data was over 90% in both regions. Results indicate that ecology based Landsat TM image analysis provides a new way to predict snail distribution under specific environmental conditions associated with the extent of the annual flood season.

GIS prediction model of malaria transmission in Jiangsu province / 中华预防医学杂志

<p><b>OBJECTIVES</b>To perform GIS spatial analysis on malaria transmission patterns in Jiangsu after setting up a malaria database and developing GIS model of malaria transmission in Jiangsu province.</p><p><b>METHODS</b>The epidemiological GIS database of malaria in Jiangsu province was established using ArcView 3.0a software. The climate data covering Jiangsu province and its peripheral area were extracted from the FAOCLIM database, the total growing degree days (TGDD) for Plasmodium vivax were calculated, and spatial distribution for TGDD was analyzed by ArcVeiw 3.0a.</p><p><b>RESULTS</b>The predicted malaria distribution map based on TGDD was created, which showed that the transmission of malaria decreased gradually from west to east, which can be divided into three belts according to the degree of transmission. The 14-year mean morbidity distribution map of malaria in Jiangsu showed that the middle and west parts of Jiangsu is the most serious endemic area. The morbidity in the areas along the Taihu valley, such as Suzhou, Wuxi and Changzhou, as well as Nantong and a few of northern counties are the lowest. The morbidity of other places is at the middle level. The 14-year mean morbidity distribution map of malaria is correlated with predicted malaria distribution map for TGDD.</p><p><b>CONCLUSION</b>It is possible to monitor the malaria transmission by GIS predicted model based on TGDD.</p>

Initial Temperature for the Development of Schistosoma japonicum Larvae in Oncomelania hupensis / 中国寄生虫学与寄生虫病杂志

Objective To study the impact of environmental temperature on the development of Schistosoma japonicum larvae within the Oncomelania hupensis. Methods Oncomelania snails, collected from the field and free of S. japonicum infection, were exposed to miracidiae of S. japonicum in a ratio of 1∶20 and raised at 30 ℃, 27 ℃, 24 ℃, 21 ℃ and 18 ℃, respectively. The prepatent period of larvae within the Oncomelania hupensis and the developmental velocity were determined, of which the relationship with the temperature was analysed. Results The average prepatent period of cercariae in snail was (128.89?16.05) d,(95.00?21.03) d,(71.93?12.74) d and (62.74?14.19) d at 21 ℃, 24 ℃, 27 ℃, 30 ℃, respectively. The regression formulation between prepatent period and temperature was y =730.68x -0.8918 (r=0.9976, P

STUDIES ON THE POPULATION GENETICS OF ONCOMELANIA SPP.IN THE MAINLAND OF CHINA Ⅳ.ELECTROPHORETIC PATTERN OF SNAIL ALLOZYME / 中国血吸虫病防治杂志

A total of 13 allozymes of 7 populations of Oncomelania snails trom 7 provinces in the mainland China were examined by horizontal starch gel electrophoresis. Results demonstrated that out of 17 loci examined, 10 were monomorphic loci: Aldh,Ao,G6pd ,Gpdh,Hbdh,Ldh, Sdh,Est-2,Est-3,and Est-6,and 7 were polymorphic loci:Est-4,Est-5,Xdh,Mdh,Idh,Got and Ap. Banding pattern showed that six enzymes were polymorphic accounting for 46.15 % (6/13) of total enzyme systems examined. Results indicated that a certain of relative relation-ship was existed along with the significant variation presented based on their environment and location among the 7 populations of snails from the mainland of China. It was revealed that the 7 polymorphic loci were the important loci affecting the gentic variation in the differ-ent populations of Oncomelania spp.

EVALUATION ON MOLLUSCICIDAL EFFECT OF QIANGLUOCIDE POWDER BY DUSTING IN FIELDS / 中国血吸虫病防治杂志

Objective To evaluate the molluscicidal effect and the using value of qiangluocide powder by dusting in the fields. Methods The two different ways of dusting with qiangluocide and spraying with luomiecide for controlling snails were compared in the fields, and the cost-effectiveness was analysed. Results The corrected mortalities and the reduced rates for density of snails were 88.48%, 96.26%, 96.96%, 95.67%, and 87.58%, 95.40%, 96.14%, 96.67%, respectively, on the marshland in Longtan, Nanjing, 73. 65% , 98. 31% , 99. 22% , 99. 26% and 69. 30% , 98.14%, 98.84%, 98. 60% , respectively, on the marshland in Yizheng, Yangzhou, on 1 d, 3d, 7 d, 15 d after dusting with qiangliocide power; and those on 1d, 3d, 7d, 15d after the spraying with luomiecide were 69.15%, 88.01%, 86.46%, 85.56% and 75.27%, 84.99%, 87.50%, 87.96% on the marshland in Longtan, Nanjing, 18.70%, 63.11%, 1.25%, 12.60% and 34. 88% , 89. 02% , 45.37% , 46. 59% , respectively, on the marshland in Yizheng, Yangzhou. The st of dusting with qiangluocide powder was 0. 20 yuan/m2, and that of spraying with luomiecide as 0. 21 yuan/m2 for snail control in the fields. The costs of reduced one percentage for the cor rected mortalities and the density of snail were 6. 27-10. 07 yuan and 6. 21-10. 14 yuan, respectively, on 15 d after dusting with qiangluocide power and those on 15 d after spraying with luomiecide were 7. 36-83. 33 yuan and 7. 16-22. 54 yuan , respectively. Conclusion The dusting with qiangluocide powder is a promising new formulation, which is suitable for the areas without water resource and possessed of high effectiveness against snails. The method ofdusting with qian-gluocide powder for controlling snails is simple, convenient, cheap and easy to be carried out for the inspection and quality control.

DEVELOPMENTAL ZERO AND EFFECTIVE ACCUMULATED TEMPERATURE OF ONCOME LANIA EGGS UNDER CONSTANT TEMPERATURE / 中国血吸虫病防治杂志

Objective To determine the de ve lopmental zero and effective accumulated temperature of Oncomela nia eggs under con stant temperature. Methods The eggs were cultur ed under different constant temperature, and their development duration and effe ctive accumulated temperature were studied. The zero accumulated temperature (℃ ) was obtained by using an estimation mode, and the effective accumulated temp erature was obtained by effective accumulated mode of K=N(T-C). [WT5”H Z] Results The average development duration was (27.29?17 .2 9) d under 15-30 ℃, the development zero temperature was 11.79 ℃ and 38.22 ℃ u nder low and high temperature respectively, and the average development temperat ure and effective accumulated temperature were (557.76?198.95) DD and(236 .02 ?68.20) DD.Conclusion The suitable developme nt temperature of eggs is 27 ℃, the development speed and effective accumulated t e mperature of eggs increases with the temperature under given condition, but too high temperature may have negative impact on the development of eggs. The resul t can be considered as the basic biological parameter of the snail.

SURVEILLANCE OF SCHISTOSOMIASIS BETWEEN 2000 AND 2002 IN JIANGSU PROVINCE / 中国血吸虫病防治杂志

Objective To identify the trend of endemic situation among surveillance sites in Jiagsu Province from 2000 to 2002. Methods Twelve schistosomiasis surveillance sites were es-tablished ,and the longitudinal, surveillance was carried out. Results The related index of snail increased in most of surveillance sites, the rates of positive snails rose rapidly in marshlands. The infection rates of Schitosoma janponicum of cattle decreased and infection rates of human were relatively steady. However, there was still the danger of heavy endemic. Conclusion Current control strategies can not effectively adapt to the endemic situation of schistosomiasis, although which have some effects on control of morbidity. We need to study the new characteristics and rule of the endemic of schistosomiasis, and make out more effective control strategies which can suit with the current society, economies and nature environment.