Multi-intervention integrated deworming strategy for sustained control of soil-transmitted helminths infections: a case study in Jiangsu Province, China.

BACKGROUND: Soil-transmitted helminths (STH) infections still present a global health problem. Mass drug administration (MDA) is a widely applied strategy to reduce morbidity and mortality caused by STH. Yet, this approach has some shortcomings. In this study, we analyzed the impact of a multi-intervention integrated deworming approach including MDA, health education (HE), and environmental sanitation improvements (ESI) for sustained STH control in Jiangsu Province of China that was applied from 1989 to 2019. METHODS: Data, including infection rate of STH, medications used, coverage of the medication, non-hazardous lavatory rate, and household piped-water access rate in rural areas, and actions related to HE and ESI were collected (from archives) and analyzed in this retrospective descriptive study. Pearson's correlation analysis was applied to test correlations. RESULTS: There was a dramatic decline in the infection rate of STH from 1989 (59.32%) to 2019 (0.12%). From 1995 to 1999, MDA and HE were recommended in rural areas. A negative correlation was observed between infection rate and medication from 1994 to 1998 (r = - 0.882, P = 0.048). From 2000 to 2005, targeted MDA was given to high-risk populations with HE continuously promoting good sanitation behaviors. From 2006 to 2014, targeted MDA + HE and ESI were used to consolidate the control effect. ESI was strengthened from 2006, and a negative correlation was observed between the coverage rate of the non-hazardous lavatory and the infection rate from 2006 to 2019 (r = - 0.95, P < 0.001). The targeted MDA was interrupted in 2015, while continuous efforts like HE and ESI contributed in sustaining STH control. CONCLUSIONS: Multi-intervention integrated deworming strategy contributes to the reduction of STH infections. This approach is a valuable example of how different interventions can be integrated to promote durable STH control.

Alterations of physiology and gene expression due to long-term magnesium-deficiency differ between leaves and roots of Citrus reticulata.

Seedlings of Ponkan (Citrus reticulata) were irrigated with nutrient solution containing 0 (Mg-deficiency) or 1mM MgSO4 (control) every two day for 16 weeks. Thereafter, we examined magnesium (Mg)-deficiency-induced changes in leaf and root gas exchange, total soluble proteins and gene expression. Mg-deficiency lowered leaf CO2 assimilation, and increased leaf dark respiration. However, Mg-deficient roots had lower respiration. Total soluble protein level was not significantly altered by Mg-deficiency in roots, but was lower in Mg-deficient leaves than in controls. Using cDNA-AFLP, we obtained 70 and 71 differentially expressed genes from leaves and roots. These genes mainly functioned in signal transduction, stress response, carbohydrate and energy metabolism, cell transport, cell wall and cytoskeleton metabolism, nucleic acid, and protein metabolisms. Lipid metabolism (Ca(2+) signals)-related Mg-deficiency-responsive genes were isolated only from roots (leaves). Although little difference existed in the number of Mg-deficiency-responsive genes between them both, most of these genes only presented in Mg-deficient leaves or roots, and only four genes were shared by them both. Our data clearly demonstrated that Mg-deficiency-induced alterations of physiology and gene expression greatly differed between leaves and roots. In addition, we focused our discussion on the causes for photosynthetic decline in Mg-deficient leaves and the responses of roots to Mg-deficiency.

[Epidemiological Survey on Intestinal Parasitic Infections in Lhasa City in 2014].

Objective: To investigate the prevalence of parasitic infections in Lhasa, Tibet. Methods: The residents in Chengguan District, Dangxiong County, Dazi County and Qushui County were selected to participate in the study in 2014, using the stratified random sampling method. Infections with the soil-borne nematodes in feces were examined in triplicates using the Kato-Katz method. Further, the Enterobius vermicularis were examined using the cellophane anal swab method in children aged 3-12 years, and the intestinal protozoa were detected by iodine staining. The parasitic infection was analyzed by sex, age, and occupation. Comparisons were made using Chi-square test. Results: A total of 1 015 residents（39.3±18.2 years: age range, 1-89 years） participated in the study, including 391 males（38.6%） and 623 females（61.4%）. Two hundred and forty-nine participants were positive for parasitic infections, with an overall infection rate of 24.5%（249/1 015）. The infection rate was 21.7%（220/1 015） for Taenia sp., 0.2%（2/1 015） for Trichuris trichiura and E. vermicularis respectively, 4.1%（42/1 015） for Entamoeba coli, 0.4%（4/1 015） for Giardia lamblia, 0.2%（2/1 015） for Iodamoeba butschlii. No infection was found for other parasites. There was no significant sexual difference in the infection rate of Taenia (male 21.2%, 83/391; female 22.0%, 137/624), T. trichiura (male 0; female 0.3%, 2/624), E. vermicularis (male 0.3%, 2/391; female 0.2%, 1/624), E. coli (male 5.4%, 21/391; female 3.4%, 21/624), G. lamblia (male 0.8%, 3/391; female 0.2%, 1/624), or I. butschlii (male 0; female 0.3%, 2/624) (P>0.05). The Taenia sp. infection rate in the age groups of 0-17, 18-29, 30-39, 40-49, 50-59 and ≥ 60 years was 10.9%（18/165）, 14.0%（18/129）, 23.0%（43/187）, 25.3%（61/241）, 26.5%（41/155）, and 28.3%（39/138）, respectively, with significant differences between groups of 0-17 and 40-49 years and between groups of 50-59 and ≥ 60 years (P<0.01). The infection rate of E. coli, T. trichiura and I. butschlii was highest in the age group of 50-59 years（6.5%, 10/155; 0.7%, 1/155; 1.3%, 2/155 respectively）. Among various occupations, farmers showed the highest infection rate for Taenia（44.5%, 147/330）, E. coli（6.4%, 21/33）, E. vermicularis （0.6%, 2/330） and I. butschlii（0.3%, 1/330）; housewives had the highest infection rate for T. trichiura（2.5%, 1/40）; and the students had the highest infection rate for G. lamblia (0.7%, 1/134). Conclusion: There are infections with various intestinal parasites in the participants of Lhasa City, among which taenia infection reaches 20.7% while others have a low level of infection.

[Epidemiological investigation of second intermediate hosts of Clonorchis sinensis in Pizhou and Xinyi cities of Jiangsu Province].

OBJECTIVE: To understand the endemic situation of Clonorchis sinensis in its second intermediate hosts in Pizhou and Xinyi cities of Jiangsu Province, so as to provide the evidence for the further control and treatment. METHODS: Pseudorasbora parva and Abbottina rivularis were caught from the natural water body of Pizhou and Xinyi cities, and the tabletting microscopy method was applied to test the metacercaria of C. sinensis. RESULTS: Totally 1 117 fishes were caught and dissected, including 792 P. parva (70.90%) and 325 A. rivularis (29.10%). The metacercaria of C. sinensis infection rates of P. parva and A. rivularis were 29.80% (236/792) and 4.62% (15/325) respectively, and the difference between the two kinds of fishes was significant (χ² = 83.88, P < 0.01). CONCLUSION: The metacercaria of C. sinensis infection rate of freshwater fishes in Pizhou and Xinyi cities is high, and the local residents are facing the higher risk of clonorchiasis sinensis.

[Effects of training of human intestinal parasitic diseases for basic health staff in Jiangsu Province].

OBJECTIVE: To evaluate the effect of the training of human intestinal parasitic diseases for basic health staff. METHODS: A workshop including theory courses and practical operations was carried out. At the end of the workshop, the effects were evaluated through the examinations of theory and film-reading. The total score of film-reading was one hundred including reading ten modified thick Kato-Katz slides in five minutes per slide. The results were analyzed statistically with SAS 9.0. RESULTS: There were 162 trainees from 13 cities. All of them took part in the final examination. The highest score of theory test was 99 and the lowest was 60 with the average of 86.3. The average score of the female was higher than that of the male, and the average score of 30-40 years' age group was higher than that of the other groups. The average score of the staff in Northern Jiangsu Province was higher than that of the staff in southern area and middle area of Jiangsu Province (P < 0.05). The highest score of film-reading was 100 and the lowest score was 20 with the average of 73.4. Among the total 9 species, the egg detection rates of five species were more than 60.00%. The detection rate of Trichuris trichiura was highest (88.17%) and the rate of Taenia was only 14.7%. The total average score of the staff in Nanjing City was highest (181.3) and the score of the staff in Changzhou City was lowest (138.3). There were significant differences among different regions (P < 0.05). CONCLUSION: The technical capability of examining the human intestinal parasitic diseases of basic health staff is different among the different regions of Jiangsu Province. We still need to strengthen the capability of pathogen detection for basic health staff.

[Prediction of hookworm incidence with time-series model in Jiangsu Province].

OBJECTIVE: To explore the feasibility of autoregressive integrated moving average (ARIMA) to predict the infection rates of hookworm in Jiangsu Province. METHODS: From 1990 to 2006, the infection rates of hookworm were used for a training data set. As to obtain a stationary data set, the training data set was second-order differenced using the version SAS 9.0. The model parameters were screened by using the minimum information criterion. The ARIMA model was constructed to predict the infect rates of hookworm form 2007 to 2011. RESULTS: The time-series model ARIMA (1, 2, 0) was confirmed preliminarily. The model fitted well the training data set. The predictive infection rates were main accordance with the actual status of hookworm from 2007 to 2011, and the most minimum error was only 9.23%. CONCLUSION: The model constructed has a good predictive effect and applied value for control of hookworm.

[Surveillance of echinococcosis in Liyang City from 2008 to 2012].

OBJECTIVE: To investigate the Echinococcus infection of people and domestic animals in Liyang City, so as to provide the evidence for the establishment of control measures of echinococcosis. METHODS: The formerly confirmed cases and clue cases were investigated. The Echinococcus antibody in serum of children aged from 7 to 12 years old and adults in key towns and control towns was detected with ELISA, and the antigen in fecal samples of dogs in key towns was also detected. B ultrasound was applied to examine the ELISA positive cases, family member and the neighbored people around them. The sheep in the market were dissected and examined for Echinococcus. RESULTS: The Echinococcus antibody positive rates were 0.93% and 0.52% in children and adults, respectively. The Echinococcus antigen positive rate was 0.95% in dogs. There were no significant difference between the positive rates of the children and adults (CHI2 = 2.124, P > 0.05). No cases were found by ultrasonic examination and no Echinococcus infection was found in the sheep. CONCLUSION: The people with Echinococcus antibody in serum and dogs with antigen in their feces are found in the surveillance of echinococcosis, therefore, there exists the complete chain of transmission in local. Thus, in the prevention and control work for the disease, the monitoring of dog feces, quarantine of sheep from other regions, as well as the population health education in key areas should be strengthened.

[Effect of mass chemotherapy in late stage of soil-borne nematodiasis control].

OBJECTIVE: To evaluate the effects and influencing factors of mass chemotherapy in the late stage of soil-borne nematodiasis control so as to provide the evidence for the development of control programs. METHODS: Six villages were divided into three groups: the target chemotherapy, the selective chemotherapy and the control. By observation in three consecutive years, the indexes, mass infection rates, infection degrees and re-infections of soil-borne nematodes, were compared among the 3 groups. The influencing factors were also analyzed. RESULTS: The population infection rates of soil- borne nematodes decreased by 85.94%, 43.10% and 20.87%, respectively, in the three groups after chemotherapy compared with those before the intervention. A higher hookworm infection rate appeared and the chemotherapy effect was impacted in the target chemotherapy group, as some key population applied fresh human waste in vegetable plots. The re-infection rate was 16.65 times of the new infection rate. CONCLUSIONS: Chemotherapy is still useful in the late stage of soil-borne nematode control. It is more important to enhance management of using manure and health education on focus population.

[Epidemiological survey of echinococcosis in some areas of Jiangsu Province].

OBJECTIVE: To understand the prevalence of echinococcosis in some areas of Jiangsu Province, so as to provide the evidence for making practical control measures. METHODS: The cases were determined by a retrospective survey and case-clues survey. All canine feces were tested by immunological fecal antigen in the villages of the local infection suspected cases. The antigen-positive feces were detected for E. chinococcus eggs by Kato-Katz technique. A serological investigation was administrated to search infected persons by double methods of enzyme-labeled immune assay and point immuno-gold filtration assay in the focus groups around the local infection suspected cases, and some students aged from seven to twelve years in their townships and in five different-orientation townships sampled randomly in their counties. The antibody-positive people were confirmed further by using imaging detection. RESULTS: There were 10 imported cases and 16 local infection suspected cases. Twenty canine feces were positive among 1 938 samples, and the positive rate was 1.03%. However, no pathogen was found. Of 12 473 serum samples, 72 were positive in sera immunological antibody test (0.58%), but no cystic nodules were found by imaging detection. CONCLUSION: There is no direct evidence for confirming the presence of infectious source and foci of echinococcosis in Jiangsu Province. However, the surveillance of echinococcosis is still needed.

[Surveillance of soil-transmitted nematodiasis in northern Jiangsu Province from 2006 to 2010].

OBJECTIVE: To evaluate the control effect on soil-transmitted nematodiasis in surveillance sites of northern Jiangsu Province. METHODS: According to "The Monitoring Program on Soil-transmitted Nematodiasis in Jiangsu Province", the eggs of soil-transmitted nematodes were detected by the Kato-Katz technique and cellophane anal swab technique, and the infection rates were predicted by the horizontal average speed development method in the surveillance sites from 2006 to 2010. RESULTS: The overall infection rate of soil-transmitted nematodes declined to 3.13% and the intensities of the infections were mild in past 5 years in the northern Jiangsu Province, and the infection rates of Ascaris lumbricoides, hookworm, Trichuris trichiura and Enterobius vermicularis were 0.77%, 0.89%, 1.49 and 1.19%, respectively. The overall infection rates showed a downtrend. The predicted result also demonstrated that the future infection rates should keep a continuous downtrend, but the decreasing speed should be slower than before. CONCLUSION: The infections of soil-transmitted nematodes in the northern Jiangsu Province have been controlled basically, and we should adjust the control strategy including surveillance and chemotherapy in the main risk population.

[Epidemic situation and control of soil-transmitted nematodiasis in Jiangsu Province].

OBJECTIVE: To analyze the prevalence changes and the control measures of soil-transmitted nematodiases in Jiangsu Province in the recent 20 years and evaluate the control effect, so as to explore the control strategies and measures appropriate to current epidemic characteristics. METHODS: The data on surveillance, control measures and control effect of soil-transmitted nematodiases in Jiangsu Province from 1990 to 2009 were collected and analyzed. RESULTS: Different control programs were taken in different control stages in Jiangsu Province. A total of 106 916.6 thousand person-times accepted chemotherapy and 2 042.9 thousand person-times were surveyed in the last 20 years. The infection rate of soil-transmitted nematodiases was 1.31% in 2009, which decreased by 97.79% comparing with 59.32% in 1990. The results showed that the control effectiveness was significant. CONCLUSIONS: The epidemic situation of soil-transmitted nematodiases has been controlled effectively in Jiangsu province. In order to consolidate the control achievements, the control strategies should put emphasis on health education, water supply and sanitation and environment sanitation improvement, meanwhile, the surveillance and medication in key population should continue to be strengthened, as well as soil-transmitted control among migrant population.

[Process for lymphatic filariasis elimination in Jiangsu Province, China].

OBJECTIVE: To review the process of lymphatic filariasis elimination in Jiangsu Province, and summarize the control experience. METHODS: The data of epidemic status, control and surveillance of lymphatic filariasis were collected and analyzed in Jiangsu Province from 1950s to 1990s. RESULTS: Lymphatic filariasis was endemic in 71 counties (cities) among all 75 counties (cities) in Jiangsu Province. Filariasis bancrofti distributed widely in the province, and in some areas of the south of Jiangsu, there were filariasis bancrofti and Brug' s filariasis co-existing. Before 1971, the microfilaria rate (mfr) in some areas had ever reached 20. 15% , from 1979, large scale control programme was carried out and the mfr in all endemic villages decreased to below 1% , and in 1989, the rate dropped to 0.016%. By 2001, the whole regions of the province reached the criteria of filariasis elimination. CONCLUSION: The elimination of lymphatic filariasis in Jiangsu Province provides valuable experience for lymphatic filariasis control in other areas.

[Purification of Clonorchis sinensis native protein and their application in immunodiagnosis of clonorchiasis].

Lots of purified antigens have been obtained from crude antigens of Clonorchis sinensis. Some of them have applied to immunodiagnosis of clonorchiasis in laboratory. Here, we review purification methods, diagnostic efficacy and application prospect of purified antigens.

[Performance evaluation of rural latrine renovation in key schistosomiasis control areas, Jiangsu Province].

OBJECTIVE: To evaluate the hygienic, environmental, social and economic benefits achieved by rural latrine renovation in key schistosomiasis control areas, Jiangsu Province. METHODS: Eights villages (evaluation villages) that finished and the three villages (control villages) that did not finish the latrine renovation work were sampled and investigated through field visits, questionnaire, referring to information and so on, to collect relevant data, and human waste samples were detected for laboratory indicators in hygiene and environment, in key schistosomiasis control areas in three counties (cities, districts), Jiangsu Province. RESULTS: A total of 11 villages and 220 households were investigated. In the evaluation villages, the owning rate and quality conformity rate of three-format sanitary latrines were 98.6% and 98.8%, respectively. The human schistosome infection rate, intestinal parasite infection rate, the incidence of intestinal infectious diseases, and related medical costs decreased by 100%, 44.5%, 34.2% and 82.8%, respectively, compared with those before latrine renovation. In laboratory testing, the removal rates of fecal coliform values, CODcr, BOD5 and ammonia nitrogen in the third cell of household latrine were 99.99%, 68.50%, 63.17% and 52.30%, respectively, compared to those in the first cell. The village appearance had changed fundamentally, the villagers were satisfied with the latrine renovation, and their health knowledge and health behavior improved significantly. CONCLUSIONS: Rural latrine renovation in key schistosomiasis control areas has got great achievements in hygienic, environmental, social and economic benefits. It plays an important role in the promotion of schistosomiasis control, economic development and social harmony.

[Cloning, expression and evaluation on effect in serological diagnosis of cysteine protease of Clonorchis sinensis].

OBJECTIVE: To clone and express the cysteine protease of Clonorchis sinensis and evaluate its effect on immunodiagnosis of human clonorchiasis. METHODS: Based on a cysteine protease gene fragment of C. sinensis (CS-CP, GenBank accession: AF093242), a pair of primers were designed and amplified from total cDNA of C. sinensis, and the gene was cloned into plasmid pPIC9K and expressed in Pichia pastoris GS115. The expressed product was purified. Ten BALA/c mice were immunized with the purified CS-CP, and the anti CS-CP antibody in the sera of immunized mice was tested with ELISA. Finally, its effect on serodiagnosis was evaluated with Dot-ELISA and Western blot. RESULTS: The CS-CP gene (approximately 927 bp) was successfully amplified, cloned and expressed in Pichia pastoris GS115. The sera of mice immunized with purified rCS-CP could be recognized by the soluble antigen of C. sinensis adult worms and its special anti CS-CP antibody titer was high (1: 64 000). The rCS-CP was probed by Dot-ELISA and Western-blot with sera from patients with clonorchiasis and other parasitic infections, and it had a sensitivity of 91.7% (55/60) in diagnosis of clonorchiasis and a specifity of 97.6% (82/84) for healthy population. The rCS-CP had no cross-reaction with the patients of schistosomiasis japonica, but had a cross-reactivity of 20.0% (2/10) with the patients with paragonimiasis westermani. CONCLUSIONS: rCS-CP possesses a favorable diagnostic effect and it is a better serodiagnostic one among recombinant antigens.

[Malaria epidemic situation in Jiangsu Province in 2006].

In 2006, there were 767 reported malaria cases in Jiangsu Province with an incidence of 1.07 per thousand and increased by 16.57% in comparison to the previous year. Positive rate of blood examination in local febrile patients was 0.08% (293/361 896) but 1.23% (251/204 40) in mobile population (P<0.01). Cases with relapses occupied 9.00% of the total. The density of Anopheles sinensis was 0.61 per net and increased by 110% more than the year 2005 (0.29/net). It is indicated that the increase of A. sinensis density has been the main factor for malaria recurrence in the area north of Huaihe River in the Province.