Role of ecological approaches to eliminating schistosomiasis in Eryuan County evaluated by system modelling.

BACKGROUND: Schistosomiasis was severely prevalent in Yunnan Province, and it is difficult to achieve its elimination by convention approaches due to complexity of the nature. We explored the comprehensive model to eliminate schistosomiasis in Eryuan County, Yunnan Province, the People's Republic of China, through integration with the ecological protection programme in Erhai Lake, in order to promote an efficient elimination strategy. We expected that this model is able to be tailored to other local settings, which help achieve the goal of precisely eliminating the disease in Yunnan Province. METHODS: Eryuan County of Yunnan Province was chosen as the study area, where the data on environmental protection activities in Erhai Lake and on the schistosomiasis control programme were collected through different departments of Erhai County government since 2015. System modelling was performed using system dynamics software to establish a simulation model in order to evaluate the effectiveness of intervention activities. RESULTS: Ecological approaches to control schistosomiasis in Eryuan County consist of three major components: (i) implementing precise interventions to stop schistosomiasis transmission by means of controlling the source of infection, blocking the biological transmission chains and cutting off the route of disease transmission; (ii) employing ecological approaches to improve the co-effectiveness of environmental protection and schistosomiasis prevention in the study area; and (iii) strengthening the professional skills of personnel involving in the schistosomiasis control programme. Simulation results showed that this strategy could speed up the progress of schistosomiasis control programme moving from the control stage to the elimination stage. CONCLUSIONS: Ecological approaches implemented in schistosomiasis endemic areas of the Eryuan region are able to improve the co-effectiveness of environmental protection and schistosomiasis control, providing a new avenue for eliminating schistosomiasis thanks to the application of precise interventions.

[Analysis of Oncomelania hupensis status in schistosomiasis surveillance sites of Yunnan Province in 2015].

OBJECTIVE: To understand the Oncomelania hupensis distribution and infection status in the schistosomiasis surveillance sites of Yunnan Province, so as to provide the evidence for making the control and prevention measures. METHODS: Eighteen administrative villages were selected as the surveillance sites where the schistosomiasis endemic was serious in 18 epidemic counties, one village for one county. The snail status was investigated with the systematic sampling and environmental sampling methods, and the infection status of the snails was detected by a microscope and loop-mediated isothermal amplification (LAMP). The surveillance database was established and descriptively analyzed. RESULTS: In 2015, the total surveillance area was 1826.55 hm², and the area with snails was 55.03 hm², that was reduced by 57.70% as compared to that in 2013, and by 40.63% as compared to that in 2014. No new snail area was discovered, and also no schistosome infected snails were discovered. Totally 718,532 frames were surveyed, and the occurrence rate of frames with snails was 0.45% and the density of living snails was 0.013 9 snail/0.1 m². In the endemic controlled areas, the snail area and density of living snails were both the highest. The snails concentrated on the environments of paddy field, ditch, bottomland, small reservoir, and dry land, and the vegetations of rice, dry crop, weed and wood. The snail area, occurrence rate of frames with snails, total number of snails and number of living snails all showed a downward trend. No infected snails were found for three years. CONCLUSIONS: The Oncomelania hupensis snails have been effectively controlled in the national schistosomiasis surveillance sites of Yunnan Province. However, the comprehensive snail control measures still should be continually strengthened in order to consolidate the achivements.

[Evaluation of effectiveness of comprehensive schistosomiasis control project in Yunnan Province from 2004 to 2013].

OBJECTIVES: To evaluate the effect of comprehensive schistosomiasis control project in Yunnan Province after its implementation for ten years, so as to provide the evidence for formulating the future prevention and control strategy. METHODS: The data of the schistosomiasis comprehensive control project and the endemic situation were collected and analyzed to evaluate the control effect of the project in Yunnan Province from 2004 to 2013. RESULTS: After the comprehensive control project implementation for ten years, the Oncomelania hupensis snail area in Yunnan Province decreased from 4,364.79 hm2 in 2004 to 1,528.50 hm2 in 2013, with a reduction rate of 64.98%, and the occurrence rate of frames with snails and the density of living snails decreased from 4.71% and 0.26 snails/0.1 m2 in 2004 to 1.35% and 0.04 snails/0.1 m2 in 2013, with the reduction rates of 71.34% and 84.62%, respectively. The schistosome infected snails were found only in 2011 and 2013 since 2008. In 2013, the infection rates of human (0.0021%) and cattle (0.0209%) decreased by 99.84% and 99.44%, respectively, compared to those in 2004, and no acute schistosome infection cases were found since 2008. The 212 villages with relatively serious endemic situation (Type One, Type Two and Type Three) all declined to the slight endemic villages (Type Four and Type Five), therefore, they reached the criteria of schistosomiasis transmission controlled or interrupted. The awareness rates of schistosomiasis control among villagers and students in endemic areas were above 90% and 98%, respectively. CONCLUSION: The effect of the comprehensive schistosomiasis control project is significant in Yunnan Province, but the task to consolidate and enlarge the control results still remains a challenge.

[Molluscicidal effect of 5% powder of niclosamide ethanolamine salt granules (NEG) in field of mountainous areas in Yunnan Province].

OBJECTIVE: To evaluate the molluscicidal effect of 5% powder of niclosamide ethanolamine salt granules (NEG) in the field of mountainous areas in Yunnan Province. METHODS: The grasslands with Oncomelania hupensis snail habitats were chosen in Beideng Village, Heqing County, Yunnan Province, and were divided into 7 groups (groups of NEG 30 g/m2, NEG 40 g/m2, NEG 50 g/m2, NEG 40 g/m2 plus obstacle clearing, 50% niclosamide ethanolamine salt wettable powder (WPN) 6 g/m2, WPN 6 g/m2 plus obstacle clearing, and fresh water). The snail death rates and the densities of living snails were investigated and the results were compared in the different groups 7 d, 15 d, and 30 d after the implementation. RESULTS: Seven d, 15 d, and 30 d after the implementation, the snail death rates of the groups of NEG 30 g/m2, 40 g/m2, and 50 g/m2 were from 72.75 % to 95.83%, and the average descent rates of living snail densities were from 72.26% to 95.54%. Seven d, 15 d, and 30 d after the implementation, in the NEG 40 g/m2 group, the snail death rates were from 81.69% to 87.19%, and the average descent rates of living snail densities were from 81.42% to 87.91% ; in the NEG 40 g/m2 plus obstacle clearing group, the snail death rates were from 84.89% to 88.24% and the average descent rates of living snail densities were from 85.63% ~ 88.22%; in the WPN 6 g/m2 group, the snail death rates were from 85.23% to 86.17% and the average descent rates of living snail densities were from 85.76% to 86.05%; in the WPN 6 g/m2 plus obstacle clearing group, the snail death rates were from 88.89% to 92.10% and the average descent rates of living snail densities were from 86.71% to 92.20%. The obstacle clearing improved the molluscicidal effect. CONCLUSION: NEG has a good molluscicidal effect in the field of mountainous areas in Yunnan Province.

[Monitoring of sentinel mice and risk assessment of schistosomiasis transmission in key regions of Yunnan Province in 2014].

OBJECTIVE: To establish and perfect the surveillance and forecast system of schistosomiasis, and timely discover the suspicious high risk environments for preventing the human and livestock from schistosomiasis. METHODS: Eight villages of three counties were selected as survey points. Then, the surveillance and forecast of sentinel mice were carried out in the key water regions. The recovered sentinel mice were dissected in laboratory. The sentinel mouse serum antibodies against schistosome were detected by ELISA, the suspicious water contacts of residents and livestock were investigated and the results were analyzed, and the epidemic risk was assessed. RESULTS: Totally 300 sentinel mice were placed, the recovery rate was 94.67%, and the mortality rate was 8.80%. There were no mice with positive serum antibodies against schistosome, and the results of the dissection of all the sentinel mice were negative. The humans who contacted with the suspicious water were mainly villagers, students, children and fishermen by washing hands and feet, washing vegetables, harvesting, fishing and swimming. The Oncomelania hupensis snail areas, human infection rates, and cattle infection rates were obviously declined in recent 3 years. However, the epidemic risks still existed. CONCLUSION: Although schistosomiasis transmission was effectively controlled in the three counties, the comprehensive control measures still should be strengthened.

[Current prevalence situation and control strategy of schistosomiasis in Yunnan Province].

OBJECTIVE: To evaluate the current prevalence situation of schistosomiasis in Yunnan Province, so as to provide the evidence for making further control strategy. METHODS: The data of schistosomiasis were collected and analyzed statistically in Yunnan Province in 2014. RESULTS: There were 7 transmission controlled counties and 11 interrupted counties in Yunnan Province in 2014, and Oncomelania hupensis snails were not found in 5 of the 11 interrupted counties for at least 5 years. In the transmission controlled areas, the schistosomiasis endemic villages, population, farm cattle, and snail areas accounted for 80.94%, 83.72%, 79.32% and 82.00% of whole schistosomiasis endemic areas in Yunnan Province, respectively. The infection source was not completely eliminated. CONCLUSION: In the transmission controlled areas, the elimination of infection source should still be strengthened; in the transmission interrupted areas, the import infection sources should be prevented.

[Analysis of schistosomiasis endemic situation in Yunnan Province from 2009 to 2012].

OBJECTIVE: To evaluate the effect of schistosomiasis control in Yunnan Province since achieving the transmission control standards, so as to provide the evidence for formulating the next prevention and control strategy. METHODS: The schistosomiasis epidemic monitoring reports, annual reports, relevant information about Oncomrnelania hupensis snails, and schistosomiasis patient conditions were collected and analyzed for epidemic condition and characteristics of schistosomiasis in Yunnan Province from 2009 to 2012. RESULTS: The various epidemic monitoring indicators all decreased. In 2012, compared with 2009, the prevalence reduced by 33.33% after correction; the number of villages with schistosomiasis patients reduced by 55.56%; the adjusted positive rate of livestock stool tests reduced by 45.45%; the number of villages with infected cow reduced by 42.25%; the actual area with snails reduced by 13.58%; the density of living snails reduced by 25.66%, and no schistosome infected snails were found in 2012. CONCLUSION: There still exist schistosome infections in human and animals in some local areas of Yunnan Province, and it is difficult to achieve the standard of schistosomiasis transmission interrupted in a short period.

[Investigation on infection sources of schistosomiasis in mountainous regions, Nanjian County, Yunnan Province].

OBJECTIVE: To understand the types of schisotsome infection sources and their roles in schistosomiasis transmission in mountainous endemic regions in Yunnan Province, so as to provide the evidence for implementing the comprehensive control measures based on infection source control. METHODS: Two villages of typical mountainous regions in Nanjian County were chosen for field investigation. The Oncomelania hupensis snail status was surveyed by the methods of systematic and environmental sampling. The infections of schistosomiasis were surveyed in residents with the indirect haemagglutination and the hatching method, in livestock with the hatching method and in wild animals with the anatomical method and the hatching method. The distribution and pollution status of wild faeces were investigated in the snail environments nearby villages or with livestock frequent activities. The positives of schistosomiasis in wild faeces were tested with the hatching method. The pollution index of wild feces was calculated. RESULTS: A total of 533.56 hm2 were investigated in two villages, and the area with snails was 16.52 hm2. The rate of frame with snails was 1.03%, the average density of snails was 0.07 snails/0.1 m2, and no positive snails were found. The positive rate of blood examinations of population was 1.61%, but no persons were positive with the hatching method. The infection rates were 0.90%, and 0.62% in cattle and equus, respectively, and there were no positives in other livestock. Totally 472 piles of wild feces of 6 species (human, cattle, equus, goat, pig and dog) distributed in the investigation areas, and among them, the densities of wild feces of cattle, equus, and dog were 7.2, 4.3 piles/hm2, and 2.1 piles/hm2 respectively, being relatively higher than others. The hatching positive rates of wild faeces of cattle, equus, and dog were 2.27% (3/132), 2.63% (2/76), and 3.70% (1/27), respectively. The relative pollution indexes of wild faeces of cattle, equus, and dog were 80.68%, 15.89%, and 3.43%, respectively. CONCLUSIONS: After schistosomiasis transmission is controlled, the potential epidemic factors still remain in the mountainous endemic regions of schistosomiasis in Yunnan Province. The cattle are still the most infection source of schistosomiasis, but equus and dog as infection sources should be not neglected. We should extend the investigation and monitor scope of the infection sources, and carry out scientific and feasible control technique and management measures.

U-curve association between timing of renal replacement therapy initiation and in-hospital mortality in postoperative acute kidney injury.

BACKGROUND: Postoperative acute kidney injury (AKI) is associated with poor outcomes in surgical patients. This study aims to evaluate whether the timing of renal replacement therapy (RRT) initiation affects the in-hospital mortality of patients with postoperative AKI. METHODOLOGY: This multicenter retrospective observational study, which was conducted in the intensive care units (ICUs) in a tertiary hospital (National Taiwan University Hospital) and its branch hospitals in Taiwan between January, 2002, and April, 2009, included adult patients with postoperative AKI who underwent RRT for predefined indications. The demographic data, comorbid diseases, types of surgery and RRT, and the indications for RRT were documented. Patients were categorized according to the period of time between the ICU admission and RRT initiation as the early (EG, ≦1 day), intermediate (IG, 2-3 days), and late (LG, ≧4 days) groups. The in-hospital mortality rate censored at 180 day was defined as the endpoint. RESULTS: Six hundred forty-eight patients (418 men, mean age 63.0±15.9 years) were enrolled, and 379 patients (58.5%) died during the hospitalization. Both the estimated probability of death and the in-hospital mortality rates of the three groups represented U-curves. According to the Cox proportional hazard method, LG (hazard ratio, 1.527; 95% confidence interval, 1.152-2.024; P = 0.003, compared with IG group), age (1.014; 1.006-1.021), diabetes (1.279; 1.022-1.601; P = 0.031), cirrhosis (2.147; 1.421-3.242), extracorporeal membrane oxygenation support (1.811; 1.391-2.359), initial neurological dysfunction (1.448; 1.107-1.894; P = 0.007), pre-RRT mean arterial pressure (0.988; 0.981-0.995), inotropic equivalent (1.006; 1.001-1.012; P = 0.013), APACHE II scores (1.055; 1.037-1.073), and sepsis (1.939; 1.536-2.449) were independent predictors of the in-hospital mortality (All P<0.001 except otherwise stated). CONCLUSIONS: The current study found a U-curve association between the timing of the RRT initiation after the ICU admission and patients' in-hospital mortalities, and alerts physicians of certain factors affecting the outcome after the RRT initiation.

[Effects of three kinds of molluscicides in fields of mountainous areas of Yunnan Province].

The molluscicidal effects of 10% salt of quinoid- 2' ,5-dichloro-4'-nitrosalicylanilide (LDS) with dusting method, 26% amine molluscicide (MNSC) and 50% niclosamide (WPN) with insufflation method were tested in the fields of mountainous areas of Yunnan Province. After 7, 15 and 30 days of the tests, the death rates of snails, decline rates of living snail densities, and occurrence rates of frames with living snails of the 10% LDS group were 72.69%-87.16%, 74.10%-88.84%, and 20.00%-30.00%, respectively; those of the 26% MNSC group were 66.21%-91.06%, 69.55%-91.36%, and 19.44%-27.78% respectively; those of the 50% WPN group were 78.10%-90.18%, 82.44%-91.60%, 17.50%-20.00%, respectively. The results showed that the molluscicidal effects of 10% LDS, 26% MNSC and 50% WPN were basically equal.

[Molluscicidal effect of suspension concentrate of metaldehyde and niclosamide in fields of mountainous areas in Yunnan Province].

OBJECTIVE: To evaluate the molluscicidal effect of 26% suspension concentrate of metaldehyde and niclosamide (MNSC) in the fields of mountainous areas in Yunnan Province. METHODS: Some representative Oncomelania snail environments of schistosomiasis endemic regions were selected as study areas in Heqing County, Yunnan Province and 26% MNSC and 50% wettable powder of niclosamide ethanolamine salt (WPN) were used to kill the snails with the mechanical spraying and sprinkler spraying methods respectively. RESULTS: Seven, 15, 30 days after the spraying with the mechanical spraying method, in corn fields, the snail mortality rates were from 88.68% to 92.88% in the MNSC group, and from 89.86% to 90.32% in the WPN group respectively, and in the ditch, the snail mortality rates were from 89.97% to 94.46% in the MNSC group and from 90.08% to 96.74% in the WPN group respectively, and there was no significant difference between the 2 groups (P > 0.05); 7, 15, 30 days after the spraying with the sprinkler spraying method, in corn fields, the snail mortality rates were from 66.14% to 89.11% in the MNSC group, and from 78.40% to 91.22% in the WPN group, respectively, in the ditch, the snail mortality rates were from 84.13% to 94.27% in the MNSC group, and from 85.81% to 95.26% in the WPN group respectively, and there was no significant difference between the 2 groups (P > 0.05). CONCLUSION: 26% MNSC has good molluscicidal effect in the fields of mountainous areas in Yunnan Province

Acute-on-chronic kidney injury at hospital discharge is associated with long-term dialysis and mortality.

Existing chronic kidney disease (CKD) is among the most potent predictors of postoperative acute kidney injury (AKI). Here we quantified this risk in a multicenter, observational study of 9425 patients who survived to hospital discharge after major surgery. CKD was defined as a baseline estimated glomerular filtration rate <45 ml/min per 1.73 m(2). AKI was stratified according to the maximum simplified RIFLE classification at hospitalization and unresolved AKI defined as a persistent increase in serum creatinine of more than half above the baseline or the need for dialysis at discharge. A Cox proportional hazard model showed that patients with AKI-on-CKD during hospitalization had significantly worse long-term survival over a median follow-up of 4.8 years (hazard ratio, 1.7) [corrected] than patients with AKI but without CKD.The incidence of long-term dialysis was 22.4 and 0.17 per 100 person-years among patients with and without existing CKD, respectively. The adjusted hazard ratio for long-term dialysis in patients with AKI-on-CKD was 19.8 compared to patients who developed AKI without existing CKD. Furthermore, AKI-on-CKD but without kidney recovery at discharge had a worse outcome (hazard ratios of 4.6 and 213, respectively) for mortality and long-term dialysis as compared to patients without CKD or AKI. Thus, in a large cohort of postoperative patients who developed AKI, those with existing CKD were at higher risk for long-term mortality and dialysis after hospital discharge than those without. These outcomes were significantly worse in those with unresolved AKI at discharge.

Combining body mass index and serum potassium to urine potassium clearance ratio is an alternative method to predict primary aldosteronism.

BACKGROUND: Though aldosterone-renin ratio (ARR) is the current routine screening method for suspicious primary aldosteronism, we hypothesized that the simple formula combining body mass index (BMI) and serum potassium to urine potassium clearance (PUKC) ratio was comparable to ARR. METHODS: Records of patients who were referred to the National Taiwan University Hospital for investigation of primary aldosteronism from January 1995 through December 2007 were retrieved. Primary aldosteronism was diagnosed based on the modified 4-corners criteria, otherwise essential hypertension was diagnosed. In both groups, the PUKC/BMI ratio was determined as well as the ARR. Bland-Altman and mountain-plot analysis were used to validate the agreement between ARR and PUKC/BMI. Receiver operating characteristic (ROC) curves were used to compare the sensitivity and specificity of PUKC/BMI and ARR. RESULTS: The records for urinary potassium were analyzed for 177 hypertensive patients (134 patients with primary aldosteronism). ROC curves showed comparable areas under the curves of both methods (95% CI: -0.029 to 0.183; p=0.186). Bland-Altman analysis further supported the agreement between ARR and PUKC/BMI ratio. CONCLUSIONS: We found that the screening power of PUKC/BMI was as good as that of conventional ARR. With the quick and extensive availability of the PUKC/BMI method and its equivalence to ARR, this screening strategy would be a good first-line tool for massive community-based primary aldosteronism surveys.

Verification and evaluation of aldosteronism demographics in the Taiwan Primary Aldosteronism Investigation Group (TAIPAI Group).

OBJECTIVE: Current data on primary aldosteronism (PA) from Asian populations are scarce. This cohort study clarifies the attributes of patients with PA in a typical Chinese population. DESIGN: An observational cohort study. METHODS: The records of patients referred to the Hypertension Clinic from a multi-centre registration in Taiwan from January 1995 to December 2007 were reviewed. All patients with PA were classified into two subtypes: aldosterone-producing adenomas (APA) and idiopathic hyperaldosteronism (IHA); their characteristics were compared. RESULTS: Our cohort consisted of 346 patients with PA, 255 with APA and 91 with IHA. The initial hypokalaemia (59% in APA vs. 27.5% in IHA, p < 0.0001) and transtubular potassium gradient (TTKG) (6.30 ± 2.41 in APA vs. 4.91 ± 2.03 in IHA, p = 0.01) were higher in the APA group. Baseline plasma aldosterone concentration (PAC) was also significantly different between the two subgroups (49.96 ± 38.15 ng/dl in APA vs. 34.24 ± 21.47 in IHA, p < 0.0001). CONCLUSIONS: In typical Chinese PA patients, the APA subgroup had a higher proportion of hypokalaemia with elevated TTKG and higher PAC as compared with the IHA subgroup. This largest Asian database also demonstrated major differences between the Caucasian and Chinese populations including female predilection, frequent hypokalaemia, and common paralytic myopathy.

The effect of iron stores on corrected QT dispersion in patients undergoing peritoneal dialysis.

BACKGROUND: Arrhythmia and sudden death represent striking features in patients with end-stage renal disease (ESRD). Increased QT dispersion has been shown to be associated with arrhythmias. Abnormal excitability and heterogeneous cardiac iron deposition may cause the arrhythmogenesis of human siderotic heart disease. Iron overload and precipitation with its toxicity in cardiac muscles may, therefore, cause QT prolongation in dialysis patients. METHODS: A total of 102 (65 women, 37 men; mean age, 47.7 +/- 13.4 years) nondiabetic patients undergoing peritoneal dialysis (PD) were enrolled in this study. Another 102 subjects with a serum creatinine level less than 1.5 mg/dL (133 micromol/L) were used as matched control subjects. The PD patients were divided into 2 groups according to whether their computerized measurements of corrected QT (QTc) dispersion were longer than 74 ms. A value of 74 ms has been associated with risk for serious arrhythmias related to sudden death in dialysis patients. RESULTS: The QTc dispersion of PD patients was significantly longer than that of the control subjects (69.8 +/- 40.0 versus 55.2 +/- 33.6 ms; P < 0.01). Thirty-eight PD patients with QTc dispersion longer than 74 ms had lower blood pressure ( P = 0.01), fewer left ventricle masses ( P = 0.036), and lower serum albumin levels (P = 0.046) but higher levels of serum calcium (P = 0.038) and transferrin saturation (TSAT; P = 0.022) than the other patients. Multivariate analysis identified TSAT as an independent factor for QTc dispersion (r = 0.432, P < 0.001). A linear relationship showed that at 74 ms of QTc dispersion, TSAT was 35.2%. CONCLUSION: Long-term PD patients have longer QTc dispersion than subjects with normal renal function. The high body iron stores in these patients increase the risk of increased QT dispersion. The concern over iron overload in dialysis patients is not only because of its oxidative toxicity, but also its precipitation of arrhythmias, which may be measured by the surrogate marker of QTc dispersion.