Objective To investigate the factors affecting the distribution of Pomacea and project the trends in the spread of suitable distribution areas of Pomacea in 2050 and 2070 in Dali Bai Autonomous Prefecture, so as to provide insights into Pomacea control in the prefecture. Methods The longitudes and latitudes of Pomacea sampling sites were captured based on Pomacea field survey data in 12 cities (counties) of Dali Bai Autonomous Prefecture from 2023 to 2024. A total of 19 climatic factors (annual mean temperature, mean diurnal range, isothermality, temperature seasonality, maximum temperature of the warmest month, minimum temperature of the coldest month, temperature annual range, mean temperature of the wettest quarter, mean temperature of the driest quarter, mean temperature of the warmest month, mean temperature of the coldest month, annual precipitation, precipitation of the wettest month, precipitation of the driest month, precipitation seasonality, precipitation of the wettest quarter, precipitation of the driest quarter, mean temperature of the warmest quarter, and mean temperature of the coldest quarter) and representative concentration pathways (RCPs) were retrieved from the world climate database (www.worldclim.org). All climatic variables were employed to create a maximum entropy (MaxEnt) model. The predictive accuracy of the model was assessed with the area under the receiver operating characteristic (ROC) curve (AUC), and the contributions of these 19 climatic factors to the distribution of Pomacea were analyzed in Dali Bai Autonomous Prefecture using Jackknife test. In addition, the suitable distribution areas of Pomacea were predicted with the MaxEnt model in Dali Bai Autonomous Prefecture in 2024 and in 2050 and 2070 under RCP4.5. Results Data pertaining to 91 Pomacea sampling sites were captured. ROC analysis revealed the MaxEnt model had an AUC value of 0.885 ± 0.088 for predicting the suitable distribution areas of Pomacea in Dali Bai Autonomous Prefecture. Of the 19 climatic factors, the maximum temperature of the warmest month had the highest contribution to the distribution of Pomacea in Dali Bai Autonomous Prefecture, followed by mean temperature of the driest quarter, mean temperature of the wettest quarter and minimum temperature of the coldest month. The suitable distribution area of Pomacea was predicted to be 14 555.69 km² in Dali Bai Autonomous Prefecture in 2024, and would expand gradually to the southeastern part of the prefecture in the future due to climatic factors. The suitable distribution areas of Pomacea were projected to expand to 21 475.61 km² in 2050 and 25 782.52 km² in 2070 in Dali Bai Autonomous Prefecture, respectively. Conclusions Temperature is an important contributor to the distribution of Pomacea in Dali Bai Autonomous Prefecture, and the suitable distribution area of Pomacea will gradually expand to the southeastern part of the prefecture in 2050 and 2070.

Anopheles stephensi is an important malaria vector in many Southeast Asian countries, and is also a widely distributed Anopheles species in parts of Asia. As a potential vector of malaria and other mosquito-borne diseases, Anopheles stephensi had a relative wide distribution in China. This review gives a brief overview of the morphological characteristics and geographical distribution of Anopheles stephensi, which has been reported in South China, Southwest China and East China, including but not limited to Guangdong, Guangxi, Hainan, Guizhou, Sichuan, Xizang, Yunnan, Fujian and other provinces. Thanks to the continuous and effective disease surveillance and mosquito control strategies, the risk of malaria epidemic in China has been greatly reduced. However, Anopheles stepheni is highly invasive and adaptable, in addition to its rapid spread in global distribution, together with global climate anomalies and other factors, there still exists a certain transmission risk of the diseases related to Anopheles stepheni in some parts of China. In order to consolidate the achievements of malaria prevention and control, it is still necessary to conduct continuous monitoring of Anopheles stephensi and other malaria vectors, and to consolidate the implementation of malaria control measures in China.

Objective To investigate the changes in eosinophil counts and the activation of microglial cells in the brain tissues of mice at different stages of Angiostrongylus cantonensis infection, and to examine the role of microglia in regulating the progression of angiostrongyliasis and unravel the possible molecular mechanisms. Methods Fifty BALB/c mice were randomly divided into the control group and the 7-d, 14-d, 21-day and 25-d infection groups, of 10 mice in each group. All mice in infection groups were infected with 30 stage III A. cantonensis larvae by gavage, and animals in the control group was given an equal amount of physiological saline. Five mice were collected from each of infection groups on days 7, 14, 21 d and 25 d post-infection, and 5 mice were collected from the control group on the day of oral gavage. The general and focal functional impairment was scored using the Clark scoring method to assess the degree of mouse neurological impairment. Five mice from each of infection groups were sacrificed on days 7, 14, 21 d and 25 d post-infection, and 5 mice from the control group were sacrificed on the day of oral gavage. Mouse brain tissues were sampled, and the pathological changes of brain tissues were dynamically observed using hematoxylin and eosin (HE) staining. Immunofluorescence staining with eosinophilic cationic protein (ECP) and ionized calcium binding adaptor molecule 1 (Iba1) was used to assess the degree of eosinophil infiltration and the counts of microglial cells in mouse brain tissues in each group, and the morphological parameters of microglial cells (skeleton analysis and fractal analysis) were quantified by using Image J software to determine the morphological changes of microglial cells. In addition, the expression of M1 microglia markers Fcγ receptor III (Fcgr3), Fcγ receptor IIb (Fcgr2b) and CD86 antigen (Cd86), M2 microglia markers Arginase 1 (Arg1), macrophage mannose receptor C-type 1 (Mrc1), chitinase-like 3 (Chil3), and phagocytosis genes myeloid cell triggering receptor expressed on myeloid cells 2 (Trem2), CD68 antigen (Cd68), and apolipoprotein E (Apoe) was quantified using real-time quantitative reverse transcription PCR (RT-qPCR) assay in the mouse cerebral cortex of mice post-infection. Results A large number of A. cantonensis larvae were seen on the mouse meninges surface post-infection, and many neuronal nuclei were crumpled and deeply stained, with a large number of bleeding points in the meninges. The median Clark scores of mouse general functional impairment were 0 (interquartile range, 0), 0 (interquartile range, 0.5), 6 (interquartile range, 1.0), 14 (interquartile range, 8.5) points and 20 (interquartile range, 9.0) points in the control group and the 7-d, 14-d, 21-d and 25-d groups, respectively (H = 22.45, P < 0.01), and the median Clark scores of mouse focal functional impairment were 0 (interquartile range, 0), 2 (interquartile range, 2.5), 7 (interquartile range, 3.0), 18 (interquartile range, 5.0) points and 25 (interquartile range, 6.5) points in the control group and the 7-d, 14-d, 21-d and 25-d groups, respectively (H = 22.72, P < 0.01). The mean scores of mice general and focal functional impairment were all higher in the infection groups than in the control group (all P values < 0.05). Immunofluorescence staining showed a significant difference in the eosinophil counts in mouse brain tissues among the five groups (F = 40.05, P < 0.000 1), and the eosinophil counts were significantly higher in mouse brain tissues in the 14-d (3.08 ± 0.78) and 21-d infection groups (5.97 ± 1.37) than in the control group (1.00 ± 0.28) (both P values < 0.05). Semi-quantitative analysis of microglia immunofluorescence showed a significant difference in the counts of microglial cells among the five groups (F = 17.66, P < 0.000 1), and higher Iba1 levels were detected in mouse brain tissues in 14-d (5.75 ± 1.28), 21-d (6.23 ± 1.89) and 25-d infection groups (3.70 ± 1.30) than in the control group (1.00 ± 0.30) (all P values < 0.05). Skeleton and fractal analyses showed that the branch length [(162.04 ± 34.10) μm vs. (395.37 ± 64.11) μm; t = 5.566, P < 0.05] and fractal dimension of microglial cells (1.30 ± 0.01 vs. 1.41 ± 0.03; t = 5.266, P < 0.05) were reduced in mouse brain tissues in the 21-d infection group relative to the control group. In addition, there were significant differences among the 5 groups in terms of M1 and M2 microglia markers Fcgr3 (F = 48.34, P < 0.05), Fcgr2b (F = 55.46, P < 0.05), Cd86 (F = 24.44, P < 0.05), Arg1 (F = 31.18, P < 0.05), Mrc1 (F = 15.42, P < 0.05) and Chil3 (F = 24.41, P < 0.05), as well as phagocytosis markers Trem2 (F = 21.19, P < 0.05), Cd68 (F = 43.95, P < 0.05) and Apoe (F = 7.12, P < 0.05) in mice brain tissues. Conclusions A. cantonensis infections may induce severe pathological injuries in mouse brain tissues that are characterized by massive eosinophil infiltration and persistent activation of microglia cells, thereby resulting in progressive deterioration of neurological functions.

Objective To investigate the origin of Biomphalaria straminea in China, so as to provide insights into assessment of schistosomiasis mansoni transmission risk and B. straminea control. Methods Guanlan River, Dasha River, Shenzhen Reservoir, upper and lower reaches of Kuiyong River, and Xinzhen River in Shenzhen, China, were selected as sampling sites. Ten Biomphalaria samples were collected from each site, and genomic DNA was extracted from Biomphalaria samples. DNA samples were obtained from 15 B. straminea sampled from 5 sampling sites in Minas Gerais State, Pará State, Federal District, Pernambuco State, and Sao Paulo State in Brazil, South America. Cytochrome c oxidase I (COI) and mitochondrial 16S ribosomal RNA (16S rRNA) genes were sampled using the above DNA templates, and the amplified products were sequenced. The COI and 16S rRNA gene sequences were downloaded from GenBank, and the sampling sites were acquired. All COI and 16S rRNA gene sequences were aligned and evolutionary trees of B. straminea were created based on COI and 16S rRNA gene sequences to identify the genetic similarity and evolutionary relationship between B. straminea samples from China and South America. Results A total of 60 COI gene sequences with a length of 529 bp and 3 haplotypes were obtained from B. straminea sampled from China. There were 165 COI gene sequences of B. straminea retrieved from GenBank, and following alignment with the above 60 gene sequences, a total of 33 haplotypes were obtained. Phylogenetic analysis showed that the three haplotypes of B. straminea from China were clustered into one clade, among which the haplotype China11 and three B. straminea samples from Brazil retrieved from GenBank belonged to the same haplotype. Geographical evolution analysis showed that the B. straminea samples from three sampling sites along eastern coasts of Brazil had the same haplotype with China11, and B. straminea samples from other two sampling sites were closely, genetically related to China11. A total of 60 16S rDNA gene sequences with approximately 322 bp in length were amplified from B. straminea in China, with 2 haplotypes identified. A total of 70 16S rDNA gene sequences of B. straminea were captured from GenBank. Phylogenetic analysis showed that Biomphalaria snails collected from China were clustered into a clade, and the haplotype China64 and the haplotype 229BS from Brazil shared the same haplotype. The 49 16S rDNA gene sequences of B. straminea from 25 sampling sites in southern Brazil, which were captured from GenBank, were included in the present analysis, and the B. straminea from 3 sampling sites shared the same haplotype with China64 in China. Geographical evolution analysis based on COI and 16S rRNA gene sequences showed that B. straminea sampled from eastern coastal areas of Brazil shared the same haplotypes in two gene fragment sequences with Biomphalaria snails collected from China. Conclusions The Biomphalaria snails in China are characterized as B. straminea, which have a low genetic diversity. The Biomphalaria snails in China have a high genetic similarity with B. straminea sampled from eastern coastal areas of Brazil, which may have originated from the eastern coastal areas of Brazil.

Objective To evaluate the potential risk of transmission of angiostrongyliasis by common freshwater snails in Dali Bai Autonomous Prefecture, Yunnan Province, so as to provide insights into local surveillance of angiostrongyliasis. Methods Common freshwater snails were collected from Dali Bai Autonomous Prefecture, Yunnan Province from March to April, 2020, and identified and bred in laboratory. SD rats were infected with third-stage larvae of Angiostrongylus cantonensis that were isolated from commercially available Pomacea canaliculata snails in Dali Bai Autonomous Prefecture, and freshwater snails were infected with the first-stage larvae of A. cantonensis that were isolated from the feces of SD rats 39 days post-infection at room temperature. The developmental process and morphological characteristics of worms in hosts were observed, and the percentages of A. cantonensis infections in different species of freshwater snails were calculated. Then, SD rats were infected with the third-stage larvae of A. cantonensis that were isolated from A. cantonensis-infected freshwater snails, and the larval development and reproduction was observed. Results More than 3 000 freshwater snail samples were collected from farmlands, ditches and wetlands around Erhai Lake in Dali Bai Autonomous Prefecture, and Cipangopaludina chinensis, P. canaliculata, Parafossarulus striatulus, Oncomelania hupensis robertsoni, Galba pervia, Physa acuta, Radix swinhoei, Assiminea spp., Tricula spp. and Bellamya spp. were morphologically identified. A total of 105 commercially available P. canaliculata snails were tested for A. cantonensis infections, and 2 P. canaliculata snails were found to be infected with A. cantonensis, in which the third-stage larvae of A. cantonensis were isolated. Ten species of freshwater snails were artificially infected with the third-stage larvae of A. cantonensis, and all 10 species of freshwater snails were found to be infected with A. cantonensis, with the highest positive rate of A. cantonensis infections in Bellamya spp. (62.3%, 137/204), and the lowest in C. chinensis (35.5%, 11/31). After SD rats were infected with the third-stage larvae of A. cantonensis isolated from different species of freshwater snails, mature adult worms of A. cantonensis were yielded. Conclusions Multiple species of freshwater snails may serve as intermediate hosts of A. cantonensis under laboratory conditions in Dali Bai Autonomous Prefecture of Yunnan Province. Further investigations on natural infection of A. cantonensis in wild snails in Dali Bai Autonomous Prefecture seem justified.

Objective:To study the population distribution of Pomacea spp. in Shandong Province and the risk of angiostrongyliasis cantonensis in the local population, and to provide a basis for scientific prevention and control of related diseases. Methods:From July to December 2021, Yanzhou District of Jining City, Ningyang County of Taian City, and Dongying District of Dongying City were selected as surveillance sites to investigate the population and distribution range of Pomacea spp., live snail samples were collected for morphological and genetic identification, and Pomacea spp. infected with the larva of Angiostrongylus cantonensis was detected by lung test. At the same time, sentinel hospital case surveillance was carried out in Yanzhou District, Jining City, and questionnaire was used to study the local residents' awareness of angiostrongyliasis cantonensis and their personal health behaviors. Results:A total of 312 live snail samples were collected. After morphological identification, they were all Pomacea spp.. After gene sequencing, two populations of Pomacea canaliculata and Pomacea maculata were found. No positive snails infected with Angiostrongylus cantonensis were found. A total of 126 patients with headache as the main neurological symptom were admitted to the sentinel hospital, but there were no monitoring cases that met the inclusion criteria. Among the survey population, 48.38% (134/277) of the respondents had heard of angiostrongyliasis cantonensis, 44.77% (124/277) knew that eating Margarya melanioides might cause angiostrongyliasis cantonensis, and 83.39% (231/277) had no related unhealthy eating behavior. Conclusion:Pomacea spp. is found and reported for the first time in Shandong Province, and there is a risk of population infection with angiostrongyliasis cantonensis.

Angiostrongyliasis cantonensis is an emerging infectious disease in China. Snails are intermediate hosts of Angiostrongylus cantonensis and play a critical role in the transmission of angiostrongyliasis cantonensis. Detection of A. cantonensis in snails is an important part of epidemiological surveys. Currently, the rapid developments in the techniques for detection of A. cantonensis in snails facilitate the surveillance of angiostrongyliasis cantonensis and provide an important support for angiostrongyliasis cantonensis prevention and control. This review summarizes the advances in the techniques for detection of A. cantonensis in snails.

Angiostrongylus cantonensis is a food-borne zoonotic parasite, and human infection may cause eosinophilic meningitis. Non-coding RNAs (ncRNAs) may regulate physiological and pathological processes at multiple biological levels; however, there are few studies pertaining to the regulatory role of ncRNAs in A. cantonensis infection. Based on publications retrieved from PubMed, Wanfang Data and CNKI, the regulatory role of ncRNAs in A. cantonensis infections mainly includes immune responses, cell apoptosis and signaling transduction, and ncRNAs may serve as biomarkers for diagnosis of angiostrongyliasis. This review summarizes the main roles of ncRNAs in A. cantonensis infections and the underlying mechanisms, so as to provide insights into diagnosis and treatment of angiostrongyliasis.

Objective: To analyze the epidemiological and clinical characteristics of patients with 2019 novel coronavirus (2019-nCoV) infection in Shenyang. Methods: The epidemiological and clinical characteristics of 30 patients diagnosed with 2019-nCoV infection admitted to Shenyang sixth people's hospital on January 22, 2020 and February 8, 2020 were retrospectively analyzed. Results: Among the 30 cases, 21 were imported, including 17 from Hubei Province and four from other provinces. Nine cases were local infections. There were 18 men and 12 women, aging from 21 to 72 years with the median of 43 years. Eight cases had underlying diseases including hypertension, diabetes, coronary heart disease and bronchitis. On admission, two (7%) cases were mild, 19 (63%) cases were ordinary, eight (27%) cases were severe, and one (3%) case was critical. Clinical manifestations mainly include fever, with or without upper respiratory tract symptoms, normal, decreased or slightly increased white blood cell counts, mainly decreased lymphocyte counts, normal or increased c-reactive protein, and normal procalcitonin. The computed tomography (CT) of the early stage of the lungs showed that multiple patchy ground glass shadows were mainly accompanied by consolidation, which often involved both lungs or multiple lobes of one lung. At the moment, the clinical treatment mainly included respiratory support, symptomatic treatment, antiviral treatment adn anti-bacterial treatment. By February 15, a total of nine cases were cured and discharged, including one mild case, six ordinary cases, and two severe cases. In the comparisons between mild/ordinary patients and severe/critical patients, the fever duration in the severe/critical group (median 11.5 d) was significantly longer than that in the light/normal group (median 2 d) (Z=-2.292, P=0.022), and the laboratory tests indicated elevated d-dimer levels (Z=-2.669, P=0.008) and more cases with neutrophilic/lymphocyte ratio > 3 (Z=-4.071, P<0.01). Conclusions In Shenyang, the early cases with 2019-nCoV infection are mainly imported cases, and expanding local infections gradually develop. Clinical manifestations are mainly characterized by fever and cough. Lung CT performance shows multiple ground glass shadows, mainly accompanied by consolidation. CT changes in the lungs should be closely monitored during the treatment, and CT findings in the lungs may change earlier than the clinical manifestations. Prolonged fever duration, elevated d-dimer level and neutrophil/lymphocyte ratio >3 could be used as early warning indicators for severe cases.

Objective To study the dynamic diffusion characteristics of Biomphalaria straminea in Shenzhen, Dongguan and Huizhou of Southern China. Methods B. straminea was monitored at 25 investigation points along 10 river channels in Shenzhen, Dongguan and Huizhou by salvaging method. The diffusion characteristics of snails along with water in the Guihua New Village section of the Guanlan River and the Dawei Village section of the Longgang River were analyzed by GPS location drift test. In addition, the influence of flooding on the diffusion of B. straminea in the Kuichong River both before and after Typhoon ^"Shanzhu^" was analyzed by monitoring the hydrology and distribution of snails. Results In March and October from 2016 to 2018, a total of 1 176 kg of floating objects were salvaged in rivers in Shenzhen, Dongguan and Huizhou. Scattered B. straminea were found on water hyacinths. Drift test of floats with GPS showed that the average drift speed of GPS floating objects was close to the river surface velocity. Affected by river current and wind direction, the GPS floats quickly drifted to the river bank and stopped in the stagnant area due to the blockade of water plants, stone and the bending of the shoreline. The drift distance of each time was between 136 - 715m. The test results of salvaged floating objects found that the loss rates of B. straminea were 46.70% - 60.00% and 22.10% - 30.80%, in the Guihua New Village section of the Guanlan River and the Dawei Village section of the Longgang River, respectively, which were significantly affected by the floating weight, river velocity and drifting distance. The analysis of the hydrology and distribution of B. straminea in the Kuichong River both before and after Typhoon ^"Shanzhu^" showed that the density of B. straminea in the river was significantly reduced by the flood. Conclusion B. straminea is mainly transported as suspended matter in water body, and flooding was an important factor in its long-distance diffusion.