[Assessment and analysis of risks of realizing schistosomiasis transmission control in Jiangxi Province].

OBJECTIVE: To evaluate the situation of realizing schistosomiasis transmission control in Jiangxi Province. METHODS: The situation of reaching the criteria of schistosomiasis transmission control was evaluated by using the method of field surveys combined with retrospective investigations. RESULTS: The schistosome infection in human was kept at a stable low level, and the infection rate in residents was below 1% in 90.24% (536/594) of whole epidemic controlled villages. There were 45 spots with schistosome infected Oncomelania hupensis snails in 38 pieces of marshland. The epidemic situation in livestock showed less optimistic than that in human, and the infection rate in bovine was higher than 1% in 19.87% (118/594) of the whole epidemic controlled villages. CONCLUSIONS: Currently, the prevalence of schistosomiasis is at a low level in 9 infection-controlled counties of Jiangxi Province. More favorable situation has emerged to the realization of schistosomiasis transmission control. However, it is necessary to strengthen the infectious sources control with emphasis on bovine so as to achieve the goal of transmission control in whole province in 2015.

[Studies on spray of niclosamide ethanolamine salt II observation on prevention of Schistosoma japonicum infection in bovine].

OBJECTIVE: To investigate the spray of niclosamide ethanolamine salt on prevention of bovine schistosomiasis in the field so as to provide a technical support for the improvement of schistosomiasis control strategy. METHODS: A total of 160 buffalo were selected as experimental objects marked by ear-mark numbers. All the buffalo were administered with praziquantel and then randomly divided into 3 groups, which were sprayed with niclosamide ethanolamine salt (500 ml per head) every 15 d (Group A), every 30 d (Group B) and an agent without niclosamide ethanolamine salt every 15 d (Group C as the control), respectively. The buffalo's droppings were collected to examine the eggs of schistosome every 30 days during the trial. RESULTS: Ninety days after the spraying, the prevalence rates of schistosomiasis were 4.00%, 4.08%, and 24.49% in the Group A, Group B, and Group C, respectively. Compared with the control group (Group C), the decline prevalence rates of schistosomiasis were 83.67% and 83.34% in the Group A and Group B, respectively. CONCLUSIONS: The buffalo spraying with 1% niclosamide ethanolamine salt can reduce schistosomiasis prevalence in bovine, that is this intervention has an obvious protective effect.

[Study on immune status of patients with schistosomiasis japonica in Poyang Lake region II characterization of cellular immune in schistosomiasis patients].

OBJECTIVE: To observe the characterization of cellular immune of schistosomiasis japonica patients in low endemic area of Poyang Lake region. METHODS: The schistosomiasis patients who were positive by stool detections were selected as study subjects, and the individuals who were negative by stool detections in three consecutive years were selected as negative controls. The CD4+T cell, CD8+T cell and CD4+CD25+Treg in venous blood of the study subjects were detected by using flow cytometry. In vitro, cytokine (IFN-gamma and IL-10) production of PBMC in response to soluble egg antigen (SEA) and soluble worm antigen preparation (SWA) were measured by ELISA. RESULTS: The levels of CD4+CD25+Treg in individuals who were positive by stool detections (5.99 +/- 1.60)% were higher than those of the negative (5.04 +/- 1.64)%, and the difference was significant (t = 3.261, P < 0.01). One year after the treatment, the levels of IFN-gamma were significantly higher (Stimulated by SEA before and after the treatment, the mean levels were 121.97 and 2 564.03 pg/ml, respectively; stimulated by SWA before and after treatment, the mean levels were 102.89 and 646.26 pg/ml, respectively) and IL-10 were significant lower in patients who were positive by stool detections (Stimulated by SEA before and after treatment, the mean level were 294.75 and 122.43 pg/ml, respectively; stimulated by SWAP before and after treatment, the mean cytokine levels were 110.10 and 31.85 pg/ml, respectively). CONCLUSION: The increase of induced CD4+CD25+Treg is one of causes that down-regulate cellular immune of human body after infection with Schistosoma japonicum.

[Study on immune status of patients with schistosomiasis japonica in Poyang Lake region I characterization of antigen-specific antibody isotype responses to Schistosoma japonicum].

OBJECTIVE: To understand the characterization and levels of antibody isotype responses to soluble egg antigen (SEA) and adult worm antigen (AWA) of Schistosoma japonicum in schistosomiasis patients in Poyang Lake region. METHODS: Antibody isotype IgG, IgG1, IgG2, IgG3, IgG4, IgE, IgM and IgA responses to SEA and AWA in the sera of individuals from endemic and non-endemic areas were determined by indirect ELISA. RESULTS: The levels of antigen-specific antibody isotypes in the sera of patients with egg positive were significantly higher than those of people with egg negative and normal control population from non-endemic area (P < 0.001), and except for anti-SEA IgG2 and anti-AWA IgG4 and IgE antibodies, the levels of antibody isotypes in the sera of people with egg negative in endemic area were significantly higher than those of normal control population from non-endemic area (P < 0.05). In the population with egg positive, children had higher levels of anti-SEA IgM and IgG1 and anti-AWA IgM antibody, and lower AWA specific IgG than adults. There was no significant difference between the male and female except for the male had higher levels of IgG (F = 4.677, P = 0.032) and IgG1 (F = 5.55, P = 0.020)against AWA. Three months post-treatment, the levels of IgG1, IgG3, IgG4 antibody responses to SEA deceased significantly (P < 0.001, P = 0.029, P = 0.044), and almost all the antibody levels decreased significantly (P < 0.05) twelve months post-treatment, except for SEA specific IgE and IgM and AWA specific IgG4 and IgM antibodies. CONCLUSIONS: The levels of antigen-specific antibody isotypes in the sera of patients with egg positive are significantly higher than those of people with egg negative and normal control population from non-endemic area. Almost all of antibody levels decrease significantly twelve months post-treatment. The levels of antibody isotypes in the sera of people with egg negative in endemic area are significantly higher than those of population from non-endemic area, giving a clue that the selection of negative control of schistosomiasis diagnostic kit should be noticed.

[Evaluation on application of common diagnosis methods for schistosomiasis japonica in endemic areas of China. III. Analysis and evaluation of underestimation of prevalence of Schistosoma japonicum infection by routine Kato-Katz technique].

OBJECTIVE: To understand the rates of underestimation of Schistosoma japonicum infection by Kato-Katz technique with different stool samples and different smears in field site. METHODS: With 27 Kato-Katz thick smears (3 stool samples with 9 thick smears each) for 3 consecutive years as a "gold standard", the rates of underestimation of schistosome infection by Kato-Katz technique with different stool samples and different smears were evaluated in a schistosomiasis endemic village. RESULTS: The examined rates of schistosome infection increased and the rates of underestimation decreased gradually with the increase of the number of Kato-Katz thick smears examined. The rates of underestimation of 3 smears were 40.98%-50.80% and the rates of underestimation of 6 smears were 25.48%-32.39%. The rates of schistosome infection based on the reading of 27 Kato-Katz thick smears were 10.96% in 2008, 8.54% in 2009 and 3.73% in 2010 respectively, but the rates of underestimation of various Kato-Katz thick smears were similar. There were no significant differences among the readings of 3, 6, and 9 smears of 1 stool sample, 3, 6 and 9 smears of 3 stool samples, 6 smears of 2 stool samples, 6 smears of 1 stool sample, and 6 smears of 3 stool samples. CONCLUSIONS: In a community with low-intensity of schistosome infection, the rate of underestimation is big by Kato-Katz technique with the reading of 3 smears of 1 stool sample. It suggested that it is better to increase smears rather than the number of stool samples examined.

[Canonical correlation and redundancy analysis on the indices of abdominal ultrasonography of schistosomiasis japonica].

OBJECTIVE: To explore the correlation of the ultrasound indices of liver and spleen in schistosomiasis japonica and with infection frequency, infection time and EPG. METHODS: The canonical correlation was applied to analyze the correlation of the hepatosplenic ultrasound indices in schistosomiasis japonica, and the correlation of the ultrasound indices with infection frequency, infection time and EPG. The proportions of variation related to each other in liver and spleen were analyzed by the redundancy analysis. RESULTS: The correlation coefficients of the first pair correlation canonical variable were 0.7842, 0.5483 and 0.5800, 0.4220, respectively, in males and females without infection, males and females with infection history (P<0.01). The correlation coefficients of the first pair correlation canonical variable were 0.6063, 0.5215 and 0.6595, 0.3849, respectively, in male negatives and female negatives, male positives and female positives (P<0.01). In groups of males and females without infection, the variations of liver ultrasound indices related with the variation of spleen ultrasound indices were 43.5% and 17.5% respectively, and in groups infection history, they were 22.1% and 11.4% respectively. In male and female negative groups, the variations of liver ultrasound indices related with the variation of spleen ultrasound indices were 26.8% and 16.8% respectively, and in positive groups, they were 27.6% and 10.7% respectively. The infection frequency, infection time and EPG in the stool-positive groups were not significantly related with the canonical variables of liver and spleen ultrasound indices (P>0.05). CONCLUSION: There is a significant canonical correlation between the liver and spleen ultrasound indices in schistosomiasis japonica, especially in males. In groups with infection history, the infection frequency, infection time and EPG of those stool-positives are not relevant to the canonical variables of liver and spleen ultrasound indices.

[Principal component analysis on ultrasound indexes of schistosomiasis and the assessment on prevalence rate].

OBJECTIVE: To explore the synthetical index for diagnosing schistosomiasis with ultrasound and to assess the prevalence rate with the index. METHODS: Ultrasound indexes of schistosomiasis Japonicum were analyzed by principal component analysis, and the synthetical indexes were assessed by ROC curve. RESULTS: Among the abnormal rates of the 6 indexes, the lowest was 1.6% comparing with the highest of 59.5%. Significant difference was noficed among the abnormal rates (chi(2) = 631.1, P < 0.01). The individual correlation of the six indexes to each other as will as with age distribution was significant (P < 0.05). The three principal components reflected the degree of pathological changes on liver and spleen. The first principal component was the factor reflecting the degree of liver pathological changes, and the second and third principal components reflected the degree of pathological changes on spleen. The synthetical index D(1) = 0.047X(1) + 0.428X(2) + 1.247X(3) + 0.095X(4) + 0.002X(5) + 0.213X(6) - 12.837 was found by adding the three weight principal components, and it's area under the ROC curve was 0.957. When -1.70 was taken as the critical value, the abnormal rate of population was 66.3%, close to the resident's actual prevalence rate 66.9%. CONCLUSION: Ultrasonography was considered as a method which could rapidly assessing the resident's prevalence rate in the endemic areas of schisitosomiasis Japonicum, and could also provide powerful information for development of strategy on chemotherapy.