Schistosoma japonicum-infected sentinel mice: Surveillance and spatial point pattern analysis in Hubei province, China, 2010-2018.

OBJECTIVES: Progress in national schistosomiasis control in China has successfully reduced disease transmission in many districts. However, a low transmission rate hinders conventional snail surveys in identifying areas at risk. In this study, Schistosoma japonicum-infected sentinel mice surveillance was conducted to identify high-risk areas of schistosomiasis transmission in Hubei province, China. METHODS: The risk of schistosomiasis transmission was assessed using sentinel mice monitoring in Hubei province from 2010 to 2018. Field detections were undertaken in June and September, and the sentinel mice were kept for approximately 35 days in a laboratory. They were then dissected to determine whether schistosome infection was present. Ripley's K-function and kernel density estimation were applied to analyze the spatial distribution and positive point pattern of schistosomiasis transmission. RESULTS: In total, 190 sentinel mice surveillance sites were selected to detect areas of schistosomiasis infection from 2010 to 2018, with 29 (15.26%) sites showing infected mice. Of 4723 dissected mice, 256 adult worms were detected in 112 infected mice. The infection rate was 2.37%, with an average of 2.28 worms detected per infected mouse. Significantly more infected mice were detected in the June samples than in the September samples (χ2=12.11, p<0.01). Ripley's L(d) index analysis showed that, when the distance was ≤34.52km, the sentinel mice infection pattern showed aggregation, with the strongest aggregation occurring at 7.86km. Three hotspots were detected using kernel density estimation: at the junction of Jingzhou District, Gong'an County, and Shashi District in Jingzhou City; in Wuhan City at the border of the Huangpi and Dongxihu Districts, and in the Hannan and Caidian Districts. CONCLUSION: The results showed that sentinel mice surveillance is useful in identifying high-risk areas, and could provide valuable information for schistosomiasis prevention and control, especially concerning areas along the Yangtze River, such as the Fu-Lun, Dongjing-Tongshun, and Juzhang River basins.

Administrative village-based spatial distribution specificity of Oncomelania hupensis and its relationship with water systems in Hubei Province / 中国血吸虫病防治杂志

Objective To investigate the spatial distribution of Oncomelania hupensis snail habitats at the administrative village scale in schistosomiasis-endemic areas of Hubei Province, so as to provide scientific bases for precise control of O. hupensis snails in the province. Methods Data regarding snail distribution at the village level in Hubei Province in 2017 were collected to create a spatial analysis database of snail distribution in Hubei Province. The spatial aggregations of O. hupensis distribution were analyzed using Moran’s I index and Local Moran’s I index. In addition, the distances from schistosomiasis-endemic villages to the Yangtze River were captured using the software ArcGIS 13.0, and their correlations with area of snail habitats were examined with the Spearman correlation method. Results O. hupensis snails were mainly distributed in 5 450 endemic villages from 63 counties of 13 cities in Hubei Province in 2017. The global spatial autocorrelation analysis showed spatial aggregations in the areas of historically accumulated snail habitats, current areas of snail habitats, areas of snail habitats outside the embankment and snail habitats inside the embankment (all Z Scores > 0, all P values < 0.05), and no spatial aggregation was seen in the areas of snail habitats in hilly areas (Z Score > 0, P > 0.05). There were four types of spatial distribution of historically accumulated areas of snail habitats, areas of current snail habitats, areas of snail habitats outside the embankment and snail habitats inside the embankment, including the high-high type (H-H type), high-low type (H-L type), low-high type (L-H type) and random distribution type, and a high percentage of the H-H type was found. There were 340, 125 and 110 endemic villages with the H-H type of areas of historically accumulated snail habitats, current areas of snail habitats and areas of snail habitats outside the embankment, and these villages were mainly concentrated in Wuhan and Jingzhou cities, with almost consistent spatial aggregation locations. There were 319 endemic villages with the H-H type of distribution of snail habitats inside the embankment, which were mainly distributed in Jingzhou, Xiaogan and Huangshi cities. In addition, the areas of historically accumulated snail habitats, current areas of snail habitats and areas of snail habitats outside the embankment negatively correlated with the distance from the endemic villages to the Yangtze River (r = −0.094, P < 0.01; r = −0.225, P < 0.01; r = −0.177, P < 0.01). Conclusion The clustering areas of snail habitats along the Yangtze River Basin, notably the villages near the Yangtze River are key regions for snail monitoring and control in Hubei Province.

Comparison of three data mining models for prediction of advanced schistosomiasis prognosis in the Hubei province.

BACKGROUND: In order to better assist medical professionals, this study aimed to develop and compare the performance of three models-a multivariate logistic regression (LR) model, an artificial neural network (ANN) model, and a decision tree (DT) model-to predict the prognosis of patients with advanced schistosomiasis residing in the Hubei province. METHODOLOGY/PRINCIPAL FINDINGS: Schistosomiasis surveillance data were collected from a previous study based on a Hubei population sample including 4136 advanced schistosomiasis cases. The predictive models use LR, ANN, and DT methods. From each of the three groups, 70% of the cases (2896 cases) were used as training data for the predictive models. The remaining 30% of the cases (1240 cases) were used as validation groups for performance comparisons between the three models. Prediction performance was evaluated using area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and accuracy. Univariate analysis indicated that 16 risk factors were significantly associated with a patient's outcome of prognosis. In the training group, the mean AUC was 0.8276 for LR, 0.9267 for ANN, and 0.8229 for DT. In the validation group, the mean AUC was 0.8349 for LR, 0.8318 for ANN, and 0.8148 for DT. The three models yielded similar results in terms of accuracy, sensitivity, and specificity. CONCLUSIONS/SIGNIFICANCE: Predictive models for advanced schistosomiasis prognosis, respectively using LR, ANN and DT models were proved to be effective approaches based on our dataset. The ANN model outperformed the LR and DT models in terms of AUC.

The inflammatory cytokine IL-22 promotes murine gliomas via proliferation.

Interleukin (IL)-22 is newly identified proinflammatory cytokine involved in the T helper (Th)17 and Th22 response. However, the possible role of IL-22 in glioma remains uncertain. The results of the present study demonstrated higher expression levels of IL-22 and the receptor IL-22BP in the brain of GL261 glioma-inoculation mice, suggesting the regulatory role of IL-22 in glioma. Injection of IL-22 increased the severity of glioma in vivo and higher expression levels of IL-6, IL-1ß and tumor necrosis factor (TNF)-α were detected in the brain using ELISA following IL-22 injection. To elucidate the mechanism underlying the effects of IL-22, the present study aimed firstly to determine the expression levels of IL-22 receptor in a glioma cell line via reverse transcription quantitative polymerase chain reaction. IL-22 treatment significantly increased the expression levels of signal transducer and activator of transcription (STAT)3 and the mRNA expression levels of STAT6 compared with the vehicle control. These results suggested that IL-22 may activate the Janus kinase (JAK)/STAT signaling pathway in glioma. Furthermore, IL-22 positively regulated the proliferation of glioma, consistent with its role in vivo. Conversely, IL-22-deficient mice exhibited prolonged survival compared with wild-type (WT) mice, and the expression levels of inflammatory cytokines were decreased in the brain of IL-22 knock-out (KO) mice compared with WT mice. Concordant with these results, it was observed that IL-22-neutralising antibody was able to increase the survival of mice with glioma and attenuate the disease by significantly reducing the cytokine levels in the brain. In conclusion, the results of the present study demonstrated that expression levels of IL-22 in the brain of mice with glioma may enhance symptoms due to the increased cytokine production of IL-6, IL-1ß and TNF-α; this is consistent with IL-6/JAK/STAT signalling activation in vitro. Decreasing the expression levels of IL-22, achieved either with IL-22-KO mice or IL-22-neutralising antibody demonstrated protective effects on glioma development. Therefore, IL-22 may serve as a potential therapeutic target for glioma.

[Molluscicidal effect comparison between TDS and MNSC in field].

OBJECTIVE: To compare the molluscicidal effects between "Luo-wei" (TDS), a plant molluscicide in 4 percent, and metaldehyde and niclosamide (MNSC) in the field. METHODS: A natural ecological environment with Oncomelania hupensis was selected as the test area, the test concentrations of TDS and MNSC were 2.5 g/m3 and 2 ml/m3 respectively by the immersion method; the test doses of TDS and MNSC were 3 g/m2 and 2 ml/m2 respectively by the spray method; the doses of WPN in a control group were 2 g/m3 and 2 g/m2 respectively by the two methods above-mentioned. The molluscicidal effects between TDS and MNSC were compared by using the synchronous design method and parallel comparative method. RESULTS: In the TDS group, the death rate of snails was 90.70% by immersion for 24 hours, reached to 81.40% after spraying for 7 days, and there were no significant differences among the observation time points in molluscicidal effects (P > 0.05). One day after the spraying, the death rate of snails was less in the TDS group compared with that in the MSCN group (P < 0.01), but the death rates of snails were similar in both groups 3 days after the spraying (P > 0.05). In the MSCN group, the death rate of snails was 99.17% by immersion for 24 hours, reached to 66.07% by spraying for 1 day. In the WPS group, the death rate of snails was 97.15% by immersion for 24 hours, reached to 71.43% after spraying for 1 day, and there were no significant differences (both P > 0.05). CONCLUSION: TDS has a good molluscicidal activity and stable efficacy, and the molluscicidal effect of TDS is similar to that of MSCN in the filed, but the molluscicidal sensitivity of TDS is lower than that of MSCN.

[Development of performance evaluation and management system on advanced schistosomiasis medical treatment].

OBJECTIVE: To construct a performance evaluation and management system on advanced schistosomiasis medical treatment, and analyze and evaluate the work of the advanced schistosomiasis medical treatment over the years. METHODS: By applying the database management technique and C++ programming technique, we inputted the information of the advanced schistosomiasis cases into the system, and comprehensively evaluated the work of the advanced schistosomiasis medical treatment through the cost-effect analysis, cost-effectiveness analysis, and cost-benefit analysis. RESULTS: We made a set of software formula about cost-effect analysis, cost-effectiveness analysis, and cost-benefit analysis. This system had many features such as clear building, easy to operate, friendly surface, convenient information input and information search. It could benefit the performance evaluation of the province's advanced schistosomiasis medical treatment work. CONCLUSION: This system can satisfy the current needs of advanced schistosomiasis medical treatment work and can be easy to be widely used.

[Analysis of advanced schistosomiasis situation in Hubei Province, 2004-2011].

There were 39 996 cases of advanced schistosomiasis in Hubei Province, 2004-2011, and most of them were of ascites type. During the period of 8 years, the assistance rate was 97.14%, the cure rate was 14.54%, the mortality rate was 5.59%, and the newly increased rates and the mortality rates declined year by year.

Protection of mice against Chlamydophila abortus infection with a bacteriophage-mediated DNA vaccine expressing the major outer membrane protein.

A bacteriophage-delivered DNA vaccine against Chlamydophila abortus was constructed by cloning a eukaryotic cassette containing the ompA gene (which expresses the Major Outer Membrane Protein) into a bacteriophage lambda vector. Four groups, each of 20 BALB/c mice were inoculated separately with the phage vaccine, a conventional DNA vaccine based on the same ompA expression cassette, a live attenuated vaccine (strain 1B) or the empty phage vector. The phage and DNA vaccines and empty phage vector were administered intramuscularly on days 0, 14 and 28; the attenuated vaccine was given once on day 0. Half the animals in each group were challenged on day 42 by intraperitoneal injection of live C. abortus and sacrificed on day 49. Phage-vaccinated mice developed moderate antibody levels against C. abortus and yielded higher levels of IFN-γ and IL-2 compared with the attenuated live vaccine group. Clearance of chlamydiae from spleens was significantly better in the attenuated vaccine group compared with the phage vaccine group, while both groups were significantly superior to the DNA vaccine and control groups (p<0.01). Although levels of protection in the mouse model were lower in phage-vaccinated animals, than in 1B vaccinated animals, phage vaccines offer several other advantages, such as easier handling and safety, potentially cheaper production and no chance of reversion to virulence. Although these are preliminary results in a model system, it is possible that with further optimisation immunization with phage vaccines may provide a novel way to improve protection against C. abortus infection and trials in large animals are currently being initiated.

Isolation and characterization of peacock Chlamydophila psittaci infection in China.

The objective of this study was to isolate and identify suspected pathogens from peacocks and peacock farmers with severe pneumonia and to investigate its potential association with peacocks' pneumonia, caused by Chlamydophila psittaci infection. A clinical examination of infected peacocks identified birds with symptoms of anorexia, weight loss, yellowish droppings, airsacculitis, sinusitis, and conjunctivitis, whereas the infected farmers showed high fever and respiratory distress. Immunofluorescence tests detected chlamydial antigens in pharyngeal swabs (12 of 20) and lung tissue samples (four of five) from peacocks. One of four swabs taken from farmers was also positive by the same test. Specific anti-chlamydia immunoglobulin G was detected in 16 of 20 peacocks and four of four peacock farmers. The isolated pathogen was able to grow in specific-pathogen-free (SPF) chicken embryos and McCoy cell lines and was identified as Chlamydiae by immunofluorescence assay and PCR. Avian influenza virus, Newcastle disease virus, and infectious bronchitis virus were eliminated as potential causative agents after pharyngeal swabs inoculated onto the chorioallantoic membrane of embryonate eggs failed to recover viable virus. PCR and restriction fragment length polymorphism indicated the ompA gene from the isolate was similar to that of avian C. psittaci type B. Three-week-old SPF chickens challenged with the peacock isolate via intraperitoneal injection showed a typical pneumonia, airsacculitis, and splenitis. Subsequently, the inoculating strain was recovered from the lungs of challenged birds. This is the first report of C. psittaci infection in peacocks and peacock farmers.

Co-administration of the polysaccharide of Lycium barbarum with DNA vaccine of Chlamydophila abortus augments protection.

Lycium barbarum polysaccharides (LBP) can stimulate moderate immune responses therefore could potentially be used as a substitute for oil adjuvants in veterinary vaccines. In the present study, it was shown that the isolated active component of LBP3a, combined with a DNA vaccine encoding the major outer membrane protein (MOMP) of Chlamydophila abortus, induced protection in mice against challenge. Sixty BALB/c mice were randomly assigned to 5 groups. Sub-fractions of polysaccharide LBP3a, at 12.5, 25 and 50 mg/kg concentrations, respectively, were mixed with a pCI-neo::MOMP (pMOMP) vaccine. Mice administrated with pCI-neo + LBP3a were served as a control. All mice were inoculated at day 0, 14, and 28, and challenged on day 44. The effects of LBp3a on serum antibody levels, in vitro lymphocyte proliferation, the activity of interleaukin-2 (IL-2), interferon-γ (IFN-γ), tumor necrosis factor α(TNF-α)and chlamydia clearance were determined. A combination of DNA vaccine and LBP3a induced significantly higher antibody levels in mice, higher T cell proliferation and higher levels of IFN-γ and IL-2. Mice immunized with DNA and LBP3a also showed significantly higher levels of chlamydia clearance in mice spleens and a greater Th1 immune response. The immunoenhancement induced by 25 mg/kg LBP3a is more effective than that induced by a 12.5 and 50 mg/kg. This implies that LBP3a at 25 mg/kg has a high potential to be used as an effective adjuvant with a DNA vaccine against swine Chlamydophila abortus.