RESUMEN
Schistosomiasis japonica remains a significant public-health problem in China. This study evaluated cost-effectiveness of a comprehensive schistosomiasis control program (2003-2006). The comprehensive control program was implemented in Zhangjia and Jianwu (cases); while standard interventions continued in Koutou and Xiajia (controls). Incurred costs were documented and the schistosomiasis comprehensive impact index (SCI) and cost-effectiveness ratio (Comprehensive Control Program Cost/SCI) were applied. In 2003, prevalence of Schistosoma japonicum infection was 11.3% (Zhangjia), 6.7% (Jianwu), 6.5% (Koutou), and 8.0% (Xiajia). In 2006, the comprehensive control program in Zhangjia and Jianwu reduced infection to 1.6% and 0.6%, respectively; while Koutou and Xiajia had a schistosomiasis prevalence of 3.2% and 13.0%, respectively. The year-by-year SCIs in Zhangjia were 0.28, 105.25, and 47.58, with an overall increase in cost-effectiveness ratio of 374.9%-544.8%. The SCIs in Jianwu were 16.21, 52.95, and 149.58, with increase in cost-effectiveness of 226.7%-1,149.4%. Investment in Koutou and Xiajia remained static (US$10,000 unit cost). The comprehensive control program implemented in the two case villages reduced median prevalence of schistosomiasis 8.5-fold. Further, the cost effectiveness ratio demonstrated that the comprehensive control program was 170% (Zhangjia) and 922.7% (Jianwu) more cost-effective. This work clearly shows the improvements in both cost and disease prevention effectiveness that a comprehensive control program-approach has on schistosomiasis infection prevalence.
Asunto(s)
Control de Enfermedades Transmisibles/métodos , Esquistosomiasis Japónica/economía , Esquistosomiasis Japónica/prevención & control , Caracoles/parasitología , Animales , Estudios de Casos y Controles , China/epidemiología , Control de Enfermedades Transmisibles/economía , Análisis Costo-Beneficio , Humanos , Ganado/parasitología , Modelos Económicos , Modelos Teóricos , Prevalencia , Estudios Retrospectivos , Esquistosomiasis Japónica/epidemiología , Estaciones del AñoRESUMEN
OBJECTIVE: To understand the status of soil-transmitted nematode infections in Poyang Lake area in Jiangxi Province. METHODS: The parasitic eggs of stools of residents aged 6-65 years were detected with the Kato-Katz technique in Fusheng Village of Poyang Lake area in Jiangxi Province in 2008. RESULTS: In 2008, the total average infection rate of soil-transmitted nematodes was 37.97%, and the infection rates of Ascarid lumbricoid, Trichuris trichiura and hookworm were 20.39%, 6.67% and 18.45%, respectively. The total infection rate of soil-transmitted nematodes and the rate ofA. lumbricoid were higher in the female than in the male with a statistically significant difference (P < 0.01). The infection rates of T. trichiura and hookworm in the female were higher than those in the male, but there was no significant difference between them (P > 0.05). The total infection rate of soil-transmitted nematodes and the rate of hookworm in different age groups had a similar change pattern which had an increasing trend with the age growing. The infection rate ofA. lumbricoid was the lowest in the age group of 10-19 years and was the highest in the age group of 20-29 years, and then the rate showed a gradually declining trend with the age increasing. The infection rate of T. trichiura had a decreasing trend as the age grew with 2 peaks in the age groups of 10-19 and 40-49, respectively. CONCLUSIONS: The infection rates of soil-transmitted nematodes in population of Fusheng Village in Jiangxi Province are still high. The effective control measures include health education, regular anthelminthic treatment, innoxiously processing of stool and environment reform, and the interruption of the transmitting chain is the fundamental strategy.
Asunto(s)
Recolección de Datos , Lagos , Infecciones por Nematodos/epidemiología , Población Rural/estadística & datos numéricos , Suelo/parasitología , Adolescente , Adulto , Animales , Niño , China/epidemiología , Heces/parasitología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nematodos/fisiología , Especificidad de la Especie , Adulto JovenRESUMEN
OBJECTIVE: To understand the schistosomiasis epidemic situation after the attainment of criteria for infection control, and evaluate the effect of control measures in Jinxian County, Jiangxi Province. METHODS: The data of schistosomiasis epidemic situation including the infection rates of residents and Oncomelania snails were collected and analyzed statistically in the infection-controlled, transmission-controlled, and transmission-interrupted areas in Jingxian County from 2008 to 2011. RESULTS: The antibody positive rates of population were decreasing year by year from 2008 to 2011 with the rate in the infection-controlled area being higher than the rates in the transmission-controlled and the transmission-interrupted areas. In the infection-controlled area, the stool examination positive cases decreased from 29 cases in 2008 to 1 in 2011. In 2008, the spots with infected snails in the infection-controlled area and the transmission-controlled area were 63 and 5 spots, respectively. The spots with infected snails in the infection-controlled and transmission-controlled areas in 2011 decreased by 95.23% and 80.00%, respectively compared with that in 2008. CONCLUSION: The schistosomiasis control measures are effective after the attainment of criteria for infection control, and the epidemic situation is stable in Jinxian County.
Asunto(s)
Control de Enfermedades Transmisibles/métodos , Esquistosomiasis/prevención & control , Animales , Bovinos , China/epidemiología , Vectores de Enfermedades , Humanos , Saneamiento , Esquistosomiasis/epidemiología , Esquistosomiasis/transmisión , Caracoles/parasitologíaRESUMEN
OBJECTIVE: To evaluate the effect of health education on prevention from schistosome infection in engineering construction workers in Poyang Lake area. METHODS: The workers for constructing "De Chang" highway in Poyang Lake area were divided randomly into an experiment group and a control group, "health education + protective skill training" was carried out in the experiment group, whereas, no intervention was implemented in the control group. RESULTS: In the experiment group, the awareness rates of schistosomiasis control knowledge were 7.96% and 96.39% before and after the intervention, respectively; the rates of contacting infested water were 100% and 1.77% pre- and post-intervention, respectively; the work protective rates increased from zero before the intervention to 100% after the intervention; there was no person infected with schistosome after the intervention. However, in the control group, all the indexes above-mentioned had no significant changes. CONCLUSION: The intervention model "health education + protective skill training", can effectively prevent from schistosome infection in engineering construction workers in Poyang Lake area.
Asunto(s)
Control de Enfermedades Transmisibles/métodos , Educación en Salud , Esquistosomiasis/prevención & control , Adolescente , Adulto , China , Industria de la Construcción , Femenino , Humanos , Lagos , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVE: To evaluate the medium-term effect and stability of the schistosomiasis comprehensive control strategy based on infectious source control after its popularization and application in marshland endemic areas. METHODS: The schistosomiasis comprehensive control strategy based on infectious source control including "replacing buffalo with machine", "marshlands isolation and grazing forbidden", etc. was implemented in all villages of Sanli Township, a heavy endemic area with schistosomiasis in Jianxian County. The infection situation of schistosomiasis in population and Oncomelania snails in 4 villages around the lake were monitored regularly for 6 consecutive years. RESULTS: The infection rate of schistosomiasis in population significantly decreased after the comprehensive control measures were carried out. Two years later, the infection rate in Huangjia Village was 0, and was sustained at zero for 5 consecutive years; the infection rate in Fengfu Village decreased by 77.24% and stabilized to zero for the next three years; the population infection rates in Fanrong Village and Caomen Village decreased by 82.33% and 82.53%, respectively, then the infection rates of the two villages kept under 1% and were 0 for 2 years and 1 year, respectively. The number of spots with infected snails in two marshlands in pilot areas decreased yearly from 10 before the intervention to 0, in which, the infection rate of snails and the number of spots with infected snails in Huangjiaoniu Marshland and Goulian Marshland decreased to zero 1 year and 3 years after the strategy was implemented, respectively, and the infected snails were not found in these marshlands in following years. CONCLUSION: Strengthening the management of buffaloes in surrounding areas and utilizing marshland resources is the main measure that can consolidate and expand the medium-term and long-term effect of the schistosomiasis 2.2 comprehensive strategy based on infectious source control.
Asunto(s)
Esquistosomiasis/prevención & control , Animales , Búfalos/parasitología , China , Humanos , Lagos , Caracoles/parasitologíaRESUMEN
The changes of snail situation in the marshlands and the economic benefit of planting were investigated after planning sesame on marshlands above 16 meters' elevation in Poyang Lake at drought period in autumn and by comparing three groups, i.e. planting sesame alone, planting sesame plus fertilizing "Rong Bao" (a brand of one fertilizer), and no planting. Results showed that the yields in the groups of planting sesame alone and planting plus fertilizing were 15.5 kg and 19.5 kg per 667 m2, respectively, with the output increasing by 25.81% in the fertilizer group. The net incomes of the two groups of planting sesame were 56.5 Yuan and -36.0 Yuan per 667 m2, respectively. One year after the planting, the living snail densities of the three groups were decreased by 97.86%, 100% and 47.62%, respectively. It is suggested that planting sesame on marshlands with snails in Poyang Lake region has a preferable economic benefit and snail control effect.
Asunto(s)
Agricultura , Control de Enfermedades Transmisibles , Vectores de Enfermedades , Caracoles/parasitología , Animales , Control de Enfermedades Transmisibles/economía , Control de Enfermedades Transmisibles/métodos , HumanosRESUMEN
OBJECTIVE: To understand the changes of transmission factors of schistosomiasis after the control strategy of replacing bovine with machine was implemented in the lake region, so as to provide the evidence for long-effective management in marshlands. METHODS: Two villages, which had carried out the control measure of replacing bovine with machine, were selected as observed villages. The data of endemic situation before and after the replacement were collected and analyzed. The species, activities, and stool distributions of infectious resources were surveyed. RESULTS: After the replacement was implemented in 2005, the densities of infected Oncomelania snails gradually decreased in the marshlands from 2006 to 2008; in 2009 and 2010, the densities of infected snails were both zero. The positive rates of stool examinations of residents in the villages decreased from 11.35% in 2004 to 0 in 2009 and 2010. There was still bovine and pig grazing on most of the marshlands, and 41 wild stools were examined with the negative results. CONCLUSION: After replacing bovine with machine is implemented, the marshlands are cleaned continuously, but there are still a few livestock on the marshlands which need to be managed.
Asunto(s)
Industria Lechera/instrumentación , Transmisión de Enfermedad Infecciosa/prevención & control , Esquistosomiasis/prevención & control , Animales , Bovinos , China/epidemiología , Control de Enfermedades Transmisibles , Humanos , Factores de Riesgo , Esquistosomiasis/epidemiología , Caracoles/parasitologíaRESUMEN
OBJECTIVE: To explore the relationship between fecal examinations and worm collection results in a community investigation of Ascaris lumbricoides infection. METHODS: A total of 1 019 residents in Zhangxi Village, Nanchang County, Jiangxi Province were investigated with the Kato-Katz technique and worm collection after deworming. RESULTS: Among 1 019 residents investigated, the actual prevalence of A. lumbricoides was 30.23%, and the egg and worm positive rates were 20.41% and 23.75%, respectively. The average burden was 2.64 worms per person, and the heavier worm burden accounted for less proportion. The heavier the worm burden, the higher the probability to got egg in the feces. If one person had 7 worms or more, the probability to got eggs in his feces was 100%. Among people of false negative fecal examination, 61.00% of them were infected with male worms only, whereas 7.00% were infected with immature female worms with or without male worms, and 32.00% were infected with mature female worms with or without male worms. Totally 32.47% of infected people were missed by fecal examination, including 22.08% without egg excreted, and 10.39% missed because of the method itself. CONCLUSION: The egg positive rate is obviously lower than the actual infection rate, and the egg detection rate is correlated with the worm burden.
Asunto(s)
Ascariasis/diagnóstico , Ascariasis/parasitología , Ascaris lumbricoides/aislamiento & purificación , Técnicas y Procedimientos Diagnósticos , Heces/parasitología , Animales , Antihelmínticos/farmacología , Ascariasis/epidemiología , Ascaris lumbricoides/efectos de los fármacos , China/epidemiología , Femenino , Humanos , Masculino , PrevalenciaRESUMEN
OBJECTIVE: To evaluate the effect of schistosomiasis control by forbidding livestock denaturing on marshland with Oncomelania snails and to analyse its influencing factors. METHODS: The village of Aiguo, Xinhe, Huangjia, Fanrong, Fengfu and Caomen and its respective nearby marshland, i.e., Aiguoniu, Liulingwei, Huangjianiu, Da, Goulian, and Litouzui, in Jinxian county, Jiangxi province were selected as the pilot areas for implementing the measures of forbidding livestock denaturing on the marshlands with Oncomelania snails during the period of the year 2005 to 2007. A total of 300 residents in each village were randomly chosen for stool examination with the Kato-Katz technique every year. The snail survey was carried out in spring and autumn every year on the marshlands close to the villages with systemic sampling method. The marshlands with a height 16.5 m above the sea level in Futian was selected for snail survey and planting with sesame. The residents aged 20 - 50 years old in Fengfu and Aiguo villages were studied by using questionnaire on the compliance of forbidding livestock pasturing on marshlands with Oncomelania snails. RESULTS: Before implementation of the measures, human infection rate with Schistosoma japonicum was 11.35% (90/793) in Aiguo, 4.00% (12/300) in Xinhe, 4.00% (6/150) in Huangjia, 8.00% (12/150) in Fanrong, 3.17% (4/126) in Fengfu and 6.64% (14/211) in Caomen. After implementation in 2008, human schistsome infection rate in the aforementioned 6 villages was declined to 0.18% (1/551), 0.00% (0/348), 0.00% (0/316), 2.27% (7/308), 1.17% (5/428) and 1.16% (5/430), respectively. Only in Fengfu village the decline of the human prevalence was not significant (χ(2) = 2.4, P = 0.12), while in the other 5 villages, human prevalence rate had been declined significantly (χ(2) = 126.77, P < 0.01; χ(2) = 16.31, P < 0.01; χ(2) = 18.79, P < 0.01; χ(2) = 10.39, P < 0.01; χ(2) = 14.17, P < 0.01, respectively). Infected snails were not found in 5 out of the 6 marshlands close to the villages. Three infected snails were founded in Da marshland because of poor environmental isolation. Before planting, the living snail density was 0.063/0.11 m(2) (34/540), and after planting, the living snail density was 0.0074/0.11 m(2) (4/538), a 88.25% reduction (Z = 12.47, P < 0.01) was recorded through economy crop planting at Futiandaan marshland in 2008. A total of 986 pieces of questionnaire were provided, and 968 valid ones were collected. The results of questionnaire indicate that compliance of forbidding livestock denaturing on marshland with Oncomelania snails in Aiguo and Fengfu villages was 84.38% (216/256) and 75.42% (537/712), respectively. Using logistic regression model, knowledge level on harmfulness of livestock denaturing on marshland with Oncomelania snails, willingness of culture with machine to substitute traditional cattle culture, and willingness of investment to marshland culture development are 3 varieties that affect residents' implementation of forbidding livestock denaturing on marshland with Oncomelania snails. CONCLUSION: The infected snail density and human schistosome infection rate were reduced on the marshlands of well environmental isolation after 2 - 3 years implementation of forbidding livestock denaturing on marshlands with Oncomelania snails. The key influencing factors of forbidding livestock denaturing on marshland with Oncomelania snails are knowledge level on harmfulness of livestock denaturing on the snail infested marshlands, the willingness of machine culture to substitute cattle culture, and the willingness of investment to marshland culture development.
Asunto(s)
Crianza de Animales Domésticos/métodos , Restauración y Remediación Ambiental , Esquistosomiasis/prevención & control , Adulto , Animales , Bovinos , Humanos , Modelos Logísticos , Persona de Mediana Edad , Factores de Riesgo , Adulto JovenRESUMEN
BACKGROUND: Schistosoma japonicum causes an infection involving humans, livestock, and snails and is a significant cause of morbidity in China. METHODS: We evaluated a comprehensive control strategy in two intervention villages and two control villages along Poyang Lake in the southeastern province of Jiangxi, where annual synchronous chemotherapy is routinely used. New interventions, implemented from 2005 through 2007, included removing cattle from snail-infested grasslands, providing farmers with mechanized farm equipment, improving sanitation by supplying tap water and building lavatories and latrines, providing boats with fecal-matter containers, and implementing an intensive health-education program. During the intervention period, we observed changes in S. japonicum infection in humans, measured the rate of infection in snails, and tested the infectivity of lake water in mice. RESULTS: After three transmission seasons, the rate of infection in humans decreased to less than 1.0% in the intervention villages, from 11.3% to 0.7% in one village and from 4.0% to 0.9% in the other (P<0.001 for both comparisons). The rate of infection in humans in control villages fluctuated but remained at baseline levels. In intervention villages, the percentage of sampling sites with infected snails decreased from 2.2% to 0.1% in one grassland area and from 0.3% to no infection in the other (P<0.001 for both comparisons). The rate of infection in mice after exposure to lake water decreased from 79% to no infection (P<0.001). CONCLUSIONS: A comprehensive control strategy based on interventions to reduce the rate of transmission of S. japonicum infection from cattle and humans to snails was highly effective. These interventions have been adopted as the national strategy to control schistosomiasis in China.
Asunto(s)
Control de Enfermedades Transmisibles/métodos , Schistosoma japonicum/aislamiento & purificación , Esquistosomiasis Japónica/prevención & control , Agricultura , Animales , China/epidemiología , Control de Enfermedades Transmisibles/economía , Costos y Análisis de Costo , Transmisión de Enfermedad Infecciosa/prevención & control , Vectores de Enfermedades , Agua Dulce/parasitología , Educación en Salud , Humanos , Saneamiento , Esquistosomiasis Japónica/epidemiología , Esquistosomiasis Japónica/transmisión , Esquistosomiasis Japónica/veterinaria , Caracoles/parasitologíaRESUMEN
OBJECTIVE: To evaluate the cost-effectiveness and cost-benefit on the integrated schistosomiasis control strategies with emphasis on infection source, and provide scientific basis for the improvement of schistosomiasis control strategy. METHODS: Aiguo and Xinhe villages in Jinxian County were selected as intervention group where the new comprehensive strategy was implemented, while Ximiao and Zuxi villages in Xinzi County served as control where routine control program was implemented. New strategy of interventions included removing cattle from snail-infested grasslands and providing farmers with farm machinery, improving sanitation by supplying tap water and building lavatories and methane gas tanks, and implementing an intensive health education program. Routine interventions were carried out in the control villages including diagnosis and treatment for human and cattle, health education, and focal mollusciciding. Data were collected from retrospective investigation and field survey for the analysis and comparison of cost-effectiveness and cost-benefit between intervention and control groups. RESULTS: The control effect of the intervention group was better than that of the control. The cost for 1% decrease of infection rate per 100 people, 100 cattle, and 100 snails in intervention group was 480.01, 6 851.24, and 683.63 Yuan, respectively, which were about 2.70, 4.37 and 20.25 times as those in the control respectively. The total cost/benefit ratio (BCR) was lower than 1 (0.94 in intervention group and 0.08 in the control). But the total benefit of intervention group was higher than that of the control from 2005 to 2008. The forecasting analysis indicated that the total BCR in intervention group would be 1.13 at the 4th year and all cost could be recalled. Sensitivity analysis revealed that the BCR in intervention group changed in the range around 1.0 and that of the control ranged blow 0.5. The cost-benefit of intervention group was evidently higher than that of the control. CONCLUSIONS: The integrated control strategy focusing on infection source control brings about triplex benefits in schistosomiasis control, social development (and ecological protection) and economic efficacy, and shows better effects and benefits than the conventional control strategy.
Asunto(s)
Esquistosomiasis/prevención & control , Animales , Bovinos , Análisis Costo-Beneficio , Humanos , Esquistosomiasis/economíaRESUMEN
OBJECTIVE: To determine the impact of a project of building dike for storing water on schistosomiasis transmission in Junshan Lake. METHODS: Junshan Lake in Jinxian County of Jiangxi Province was selected as survey pilot. Data on snail distribution and historical prevalence of schistosomiasis before building dike were collected. The water level inside and outside of the dike was recorded from 1995 to 2002, and the relationship between the water level and snail population at the inside of the dike was analyzed. Survey was made in a natural endemic village to confirm the current endemicity of schistosomiasis. RESULTS: In the selected area of Junshan lake, schistosomiasis was prevalent in 6 villages of 3 townships, with a snail area of 1,394,030 m2 (2,090 Chinese Mu). Snails distributed mainly in the marshland at an elevation of 16.6-17.2 m, and the average infection rate of schistosomiasis in the residents was 12.5% in 1958 before the dike project. In 1960, two years after the dike was built, no living snails were found on the marshland, and the infection rate of schistosomiasis in the residents reduced remarkably. Currently, no schistosomiasis cases were found in human being and cattle in the surveyed village. CONCLUSION: The reservoir project had helped the elimination of snails and interrupted schistosomiasis transmission.