[Analysis of capability of examining helminthes: National technique competition of parasitic disease diagnosis in 2013].

OBJECTIVES: To understand the ability of worm detection of staff of centers for disease control and prevention (CDC) in China, so as to promote the ability construction. METHODS: In each province, four competitors were selected from the institutions of parasitic diseases control to attend the National Technique Competition for Parasitic Disease Diagnosis and the results of competition were collected and analyzed. RESULTS: The average scores of microscopic identification and slide preparation of all the 124 competitors were 27.3 and 7.6 respectively and the scores were increased significantly (t = 3.169, 5.009, both P < 0.05) compared to those in 2012. The average detection rate of helminthes was 62.7%, and it was increased significantly (χ2 = 28.630, P < 0.05) compared to that in 2012. The scores of competitors of different genders, ages, and profession titles were significantly different (t = 1.400, 2.080, F = 2.366-3.864, all P < 0.05). The scores of competitors of provinces with the control task of parasites were higher than those without any control task (t = 6.650, 4.630, both P < 0.01). CONCLUSIONS: The competition has enhanced the ability of staff of CDCs, especially for the young staff. However, the ability of detection for soil transmitted helminth eggs should be intensified. Monitoring sites should be established in low endemic areas of parasites and provinces without the prevention and control task and the training for the professional staff should be strengthened.

[Correlation between soil-transmitted nematode infections and children's growth].

OBJECTIVE: To understand the infection status of soil-transmitted nematodes in southwest China and the correlation between soil-transmitted nematode infections and children's growth. METHODS: The prevalence of soil-transmitted nematode infections was determined by Kato-Katz technique, and in part of the children, the examination of Enterobius vermicularis eggs was performed by using the cellophane swab method. The influencing factors were surveyed by using a standardized questionnaire. The relationship between soil-transmitted nematode infections and children's growth was analyzed by the ordinary least square (OLS) method. RESULTS: A total of 1 707 children were examined, with a soil-transmitted nematode infection rate of 22.2%. The results of OLS analysis showed that there existed the negative correlation between soil-transmitted nematode infections and the indexes of children's growth including BMI, the weight-for-age Z score and height-for-age Z score. Furthermore, other correlated variables included the age, gender, educational level of mother and raising livestock and poultry, etc. CONCLUSIONS: Children' s retardation is still a serious issue in the southwest poor areas of China and correlated with the infections of soil-transmitted nematodes. For improving children's growth, it is greatly significant to enhance the deworming and health education about parasitic diseases in mothers.

[Enterobius vermicularis infection status among children in 9 provinces/autonomous regions/municipalities of China].

OBJECTIVE: To investigate the infection status of Enterobius vermicularis among children in 9 Provinces/Autonomous regions/Municipalities (P/A/M) of China, and analyze its risk factors. METHOD: From April to December 2011, one provincial capital (prefecture-level city) and one county (city, district) were chosen as investigation spots from Guangdong, Guangxi, Hainan, Chongqing, Sichuan, Zhejiang, Fujian, Anhui and Guizhou, respectively. Children aged 2 to 12 were examined by using adhesive cellophane anal swab with round-bottom tube. Information of children's family condition, health behavior and school environment were collected by questionnairing. RESULTS: 14 964 children were examined, and 14 582 qualified questionnaires were collected. The total prevalence was 17.8% (2 659/14 964). Of the 9 P/A/M, the prevalence was highest in Hainan Province (51.1%, 869/1 701) and lowest in Anhui Province (0.8%, 13/1 589). The prevalence in urban areas (7.3%, 552/7 581) was lower than that of rural areas (28.5%, 2 107/7 383) (chi2 = 1156.73, P < 0.01). The highest prevalence in urban and rural areas was found in Haikou City(38.0%, 322/847) and Wanning City (64.1%, 547/854) of Hainan Province. The prevalence rate in males and females was 17.4% (1 410/8 128) and 18.3% (1249/6 834), respectively (chi2 = 2.192, P > 0.05). The highest prevalence in males (61.2%, 300/490) and females (67.9%, 247/364) was found in children of Wanning City. Multivariate logistic regression analysis showed that residence, education level of parents, occupation of parents, nail biting, types of classroom ground and type of boarding were the risk factors on E. vermicularis infection. CONCLUSION: The prevalence of enterobiasis in children is still high in many areas of China, and the prevention and control measures should be taken according to the risk factors.

[Investigation on prevalence of soil-transmitted nematode infections and influencing factors for children in southwest areas of China].

OBJECTIVE: To understand the infection status and main risk factors of soil-transmitted nematodes in southwest China so as to provide the evidence for making the control programs for soil-transmitted nematodiasis. METHODS: The prevalence of soil-transmitted nematode infections was determined by Kato-Katz technique and influencing factors were surveyed by using a standardized questionnaire, and in part of the children, the examination of Enterobius vermicularis eggs was performed by using the cellophane swab method. The relationship between soil-transmitted nematode infections and influencing factors was analyzed by the multiple probit estimated method. RESULTS: A total of 1 707 children were examined, with a soil-transmitted nematode infection rate of 22.2%, the crowd infection rates ofAscaris lumbricoides, hookworm, and Trichuris trichiura were 16.0%, 3.8% and 6.6% respectively and 495 children were examined on Enterobius vermicularis eggs, with the infection rate of 5.1%. The results of probit estimated analysis suggested that the effects of 4 factors on soil-transmitted nematode infections were significant (all P values were less than 0.05), namely the number of sib, educational level of mother, drinking unboiled water and raising livestock and poultry. Among the factors above, the educational level of mother could reduce the probability of infection (ME = -0.074), while the number of sib, drinking unboiled water and raising livestock and poultry could increase the probability of the infections (with ME of 0.028, -0.112 and 0.080, respectively). CONCLUSIONS: Soil-transmitted nematode infection rates are still in a high level for children in southwest poor areas of China, with Ascaris lumbricoides as a priority. The changes of children's bad health habits, raising livestock and poultry habits, and implementing the health education about parasitic diseases in mothers would be of great significance for the prevention and control of soil-transmitted nematodiasis.

New perspectives on host-parasite interplay by comparative transcriptomic and proteomic analyses of Schistosoma japonicum.

Schistosomiasis remains a serious public health problem with an estimated 200 million people infected in 76 countries. Here we isolated ~ 8,400 potential protein-encoding cDNA contigs from Schistosoma japonicum after sequencing circa 84,000 expressed sequence tags. In tandem, we undertook a high-throughput proteomics approach to characterize the protein expression profiles of a number of developmental stages (cercariae, hepatic schistosomula, female and male adults, eggs, and miracidia) and tissues at the host-parasite interface (eggshell and tegument) by interrogating the protein database deduced from the contigs. Comparative analysis of these transcriptomic and proteomic data, the latter including 3,260 proteins with putative identities, revealed differential expression of genes among the various developmental stages and sexes of S. japonicum and localization of putative secretory and membrane antigens, enzymes, and other gene products on the adult tegument and eggshell, many of which displayed genetic polymorphisms. Numerous S. japonicum genes exhibited high levels of identity with those of their mammalian hosts, whereas many others appeared to be conserved only across the genus Schistosoma or Phylum Platyhelminthes. These findings are expected to provide new insights into the pathophysiology of schistosomiasis and for the development of improved interventions for disease control and will facilitate a more fundamental understanding of schistosome biology, evolution, and the host-parasite interplay.

[Study on the mixed testing of serum samples in seroepidemiological survey of parasitic diseases].

OBJECTIVE: In order to accumulate experiences for improving the efficiency in serological tests, the present study on mixed testing of serum samples was performed by taking the serological test of trichinellosis and toxoplasmosis as the examples, and had proved the effects on cost-effectiveness of seroepidemiological survey of parasitic disease with method of mixed-samples test. METHODS: According to the binomial distribution principle, to develop an approach to the feasibility of mixed testing of serum samples, and to work on a cost-effectiveness analysis of one-by-one testing and mixed testing using hygienic economic analysis method was performed. For serological test of trichinellosis and toxoplasmosis, 3 kinds of mixed testing methods, namely 3 serum sample mixture, 5 serum sample mixture and 10 serum sample mixture, were performed. RESULTS: The results showed that all the 3 kinds of mixed tests of trichinellosis and toxoplasmosis showing positive result if only 1 weak positive serum sample were mixed with. When the serum samples being mixed were all negative ones, then among the 24 groups tested with each kind of negative serum sample mixture of trichinellosis (3 serum samples, 5 serum samples and 10 serum samples), they all showed negative. However, among the 12 groups tested with 2 kinds of negative serum mixture of toxoplasmosis (3 serum samples and 5 serum samples), all showed negative while among the 18 groups tested with the 10 serum sample mixture, 16 groups showed negative and 2 were positive. The mixed testing of trichinellosis and toxoplasmosis showed that the efficiency of mixed testing was related to the serological positive rate of the parasitic diseases to be examined. When serological positive rate was 10%, the efficiency of mixed testing was higher in 4 serum sample group. When serological positive rate was 1%, the efficiency of mixed testing was higher in 10 serum sample group and when serological positive rate was 0.1%, the in crease of the size of mixed serum samples could decrease the number of testing, but the prerequisite was that there must be one positive sample, so that the positivity for all the mixed tests could be detected. If mixed testing were performed on all negative samples, no positivity could be detected. CONCLUSION: The result of cost-effectiveness analysis demonstrated that for seroepidemiological survey of parasitic diseases, the cost for mixed testing was low, especially when the serological positive rate was expected low (< or = 1%, thus the mixed testing could save a large amount of the cost.

Rapid kinetic rate assay of the serum alpha-L-fucosidase in patients with hepatocellular carcinoma by using a novel substrate.

BACKGROUND: Developing kinetic rate assay kit for alpha-L-fucosidase (AFU) by using a novel substrate 2-chloro-4-nitrophenyl-alpha-L-fucopyranoside (CNPF) and clinical implication in the diagnosis of hepatocellular carcinoma (HCC). METHODS: We have evaluated the new kinetic rate assay kit using a novel substrate for serum AFU employing Hitachi 7170 automated analyzer. The reaction was carried out at 37 degrees C, monitoring the wavelength at 405 nm. Serum samples from 884 Chinese subjects including 518 healthy adults and 366 patients were determined using this kit. RESULTS: The linearity was observed up to 300 U/L. The intra-assay precision (n=10) was S.D. 0.47; CV 2.6 (AFU activity, 17.8 U/L), S.D. 0.31; CV 0.79% (AFU activity, 39.71 U/L) and S.D. 0.79; CV 0.77% (AFU activity, 102 U/L). The day-to-day assay precision (n=10) was 3.96% (AFU activity: 41.1 U/L). There was no significant interference of various substances such as ascorbic acid (6 g/L), hemoglobin (220 mg/L) and bilirubin (200 mg/L). Serum AFU value for healthy adults was estimated at 22.8+/-7.1 U/L. No significant difference was found between male and female groups (p>0.05). The mean value of serum AFU activity in patients with HCC was significantly higher than in patients with cirrhosis, chronic hepatitis, other malignant neoplasm, other diseases and control subjects. No significant differences were found between controls and patients with cirrhosis, chronic hepatitis, patients, other malignant neoplasm and other diseases. The sensitivity and specificity was 81.5% and 85.4%, respectively. CONCLUSIONS: Serum alpha-L-fucosidase is a useful maker in the diagnosis of HCC. The assay had high sensitivity and specificity. The procedure determined is simple, rapid, convenient, and can be adapted to automated clinical analyzers for use in large-scale screening for early diagnosis of HCC.

Evolutionary and biomedical implications of a Schistosoma japonicum complementary DNA resource.

Schistosoma japonicum causes schistosomiasis in humans and livestock in the Asia-Pacific region. Knowledge of the genome of this parasite should improve understanding of schistosome-host interactions, biomedical aspects of schistosomiasis and invertebrate evolution. We assigned 43,707 expressed sequence tags (ESTs) derived from adult S. japonicum and their eggs to 13,131 gene clusters. Of these, 35% shared no similarity with known genes and 75% had not been reported previously in schistosomes. Notably, S. japonicum encoded mammalian-like receptors for insulin, progesterone, cytokines and neuropeptides, suggesting that host hormones, or endogenous parasite homologs, could orchestrate schistosome development and maturation and that schistosomes modulate anti-parasite immune responses through inhibitors, molecular mimicry and other evasion strategies.

[Prokaryotic expression of gene encoding Schistosoma japonicum SjE16 and its potential application in immunodiagnosis].

OBJECTIVE: To sub-clone and express the gene encoding Schistosoma japonicum calcium-binding protein (SjE16) and study its immunological response. METHODS: The specific primers were designed according to the expressed sequence tags (ESTs) sequence, which was used for amplification of the encoding sequence from the cDNA clone containing SjE16. The gene was subcloned into pGEX4T-1 plasmid and expressed. The rSjE16 was tested for its immunological response by ELISA. RESULTS: The gene encoding Schistosoma japonicum SjE16 was cloned and expressed successfully. The immunogenicity and diagnostic potential of rSjE16 were investigated. It was demonstrated by immunoassay in rabbits that the specificity and sensitivity of the test were 94.1% (16/17) and 88.2% (15/17), respectively, and the level of antibody titer of the untreated group reached a peak at 9-11 wk post infection and maintained high at least for 21 wk post infection, while the antibody level in the treated group rapidly decreased to pre-infection level in 11 wk after treatment. In human, the specificity of the test was 98.3% (57/58); the sensitivity of acute and chronic patient serum assay was 85.5% (53/62) and 70.2% (40/57), respectively. CONCLUSION: The recombinant protein of SjE16 (rSjE16) was acquired. It can be recognized by the sera from schistosomiasis patients, and the level of antibodies decreased quickly after treatment in experimental rabbits, which implicates the potential value for the evaluation of chemotherapy and detection of active infection.